Anderson, JF; Vossbrinck, CR; Andreadis, TG; Iton, A; Beckwith, WH 3rd; Mayo, DR. A phylogenetic approach to following West Nile virus in Connecticut. Proceedings of the National Academy of Sciences of the United States of America. 2001 Nov 6; 98(23): 12885-9. ISSN: 0027-8424.

NAL Call No.: 500 N21P

Descriptors:   genetic strains, geographic clusters of mutants, strain dissemination, phylogeny, virus classification, DNA primers, Cercopithecus-aethiops, skunk, birds, mosquitoes, Connecticut WN virus isolates.

Molecular sequence data: GENBANK/AF206517; GENBANK/AF206518; GENBANK/AF206519; GENBANK/AF206520; GENBANK/AF385215; GENBANK/AF385216; GENBANK/AF385217; GENBANK/AF385218; GENBANK/AF385219; GENBANK/AF385220; GENBANK/AF385221; GENBANK/AF385222; GENBANK/AF385223; GENBANK/AF385224; GENBANK/AF385225; GENBANK/AF385226; GENBANK/AF385227; GENBANK/AF385228; GENBANK/AF385229; GENBANK/AF385230; GENBANK/AF385231; GENBANK/AF385232; GENBANK/AF385233; GENBANK/AF385234; GENBANK/AF385235; GENBANK/AF385236; GENBANK/AF385237; GENBANK/AF385238; GENBANK/AF385239; GENBANK/AF385240; GENBANK/AF385241; GENBANK/AF385242; GENBANK/AF385243; GENBANK/AF385244; GENBANK/AF385245; GENBANK/AF385246; GENBANK/AF385247; GENBANK/AF385248; GENBANK/AF385249; GENBANK/AF385250; GENBANK/AF385251; GENBANK/AF385252; GENBANK/AF385253; GENBANK/AF385254; GENBANK/AF385255; GENBANK/AF385256; GENBANK/AF385257; GENBANK/AF385258; GENBANK/AF385259; GENBANK/AF385260; GENBANK/AF385261; GENBANK/AF385262; GENBANK/AF385263; GENBANK/AF385264; GENBANK/AF385265; GENBANK/AF385266; GENBANK/AF385267; GENBANK/AF385268; GENBANK/AF385269; GENBANK/AF385270; GENBANK/AF385271; GENBANK/AF385272; GENBANK/AF385273; GENBANK/AF385274; GENBANK/AF385275; GENBANK/AF385276; GENBANK/AF385277; GENBANK/AF385278; GENBANK/AF385279; GENBANK/AF385280; GENBANK/AF385281; GENBANK/AF385282; GENBANK/AF385283; GENBANK/AF385284; GENBANK/AF385285; GENBANK/AF385286; GENBANK/AF385287; GENBANK/AF385288; GENBANK/AF385289; GENBANK/AF385290; GENBANK/AF385291; GENBANK/AF385292

Abstract: The 1999 outbreak of West Nile (WN) virus in the northeastern United States was the first known natural occurrence of this flavivirus in the Western Hemisphere. In 1999 and 2000, 82 independent Connecticut WN virus isolates were cultured from nine species of birds, five species of mosquitoes, and one striped skunk. Nucleotide sequences obtained from these isolates identified 30 genetic changes, compared with WN-NY99, in a 921-nt region of the viral genome beginning at nucleotide position 205 and ending at 1125. This region encodes portions of the nucleocapsid and envelope proteins and includes the entire coding regions for the premembrane and membrane proteins. Amino acid changes occurred at seven loci in six isolates relative to the WN-NY99 strain. Although 34 of the isolates showed sequences identical to the WN-NY99 isolate, we were able to show geographical-based clusters of mutations. In particular, 26 isolates were characterized by mutation of C to T at position 858. This group apparently originated in Stamford, CT and disseminated to sites located as far as 54 miles from Stamford. Sequences of WN virus isolated from both brain and heart tissues from the same avian host were identical in all 14 tested individual birds, suggesting that the mutations we have documented are real and not caused by culture, RNA extraction, or PCR procedures. We conclude that this portion of the viral genome will enable us to follow the geographical and temporal movement of variant WN virus strains as they adapt to North America.  


Anderson, J F; Vossbrinck, C R; Andreadis, T G; Iton, A; Beckwith, W H 3rd; Mayo, D R. Characterization of West Nile virus from five species of mosquitoes, nine species of birds, and one mammal. Annals of the New York Academy of Sciences. 2001 Dec; 951: 328-31. ISSN: 0077-8923.

NAL Call No.: 500 N484 

Descriptors: virus genetics, isolation and purification, Culicidae, mosquitoes, phylogeny, skunks, birds. 


Andreadis, T G; Anderson, J F; Vossbrinck, C R. Mosquito surveillance for West Nile virus in Connecticut, 2000: isolation from Culex pipiens, Cx. restuans, Cx. salinarius, and Culiseta melanura. Emerging Infectious Diseases.

2001 Jul-Aug; 7(4): 670-4. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   surveillance data from June to October, mosquito infection rates with WN, seasonal differences in mosquito transmission, virus amplication patterns, Culex  species as disease vectors, sentinel surveillance, Cercopithecus aethiops, epidemiology, Vero cells, virus genetics, Connecticut.

Abstract: Fourteen isolations of West Nile (WN) virus were obtained from four mosquito species (Culex pipiens [5], Cx. restuans [4], Cx. salinarius [2], and Culiseta melanura [3]) in statewide surveillance conducted from June through October 2000. Most isolates were obtained from mosquitoes collected in densely populated residential locales in Fairfield and New Haven counties, where the highest rates of dead crow sightings were reported and where WN virus was detected in 1999. Minimum field infection rates per 1,000 mosquitoes ranged from 0.5 to 1.8 (county based) and from 1.3 to 76.9 (site specific). Cx. restuans appears to be important in initiating WN virus transmission among birds in early summer; Cx. pipiens appears to play a greater role in amplifying virus later in the season. Cs. melanura could be important in the circulation of WN virus among birds in sylvan environments; Cx. salinarius is a suspected vector of WN virus to humans and horses.


Anonymous.  Serosurveys for West Nile virus infection--New York and Connecticut counties, 2000. MMWR Morbidity and Mortality Weekly Report. 2001 Jan 26; 50(3): 37-9. ISSN: 0149-2195.

NAL Call No.: RA407.3 M56

Descriptors: West Nile fever epidemiology, areas of epizootic West Nile virus activity, CDC data, bird/avian mortality, humans, Connecticut, New York.

Abstract: In 2000, 21 persons were reported with acute illness attributed to West Nile virus (WNV) infection; 19 were hospitalized with encephalitis or meningitis. Of the 21, 10 resided in the Staten Island borough (Richmond County) of New York City. Other ill persons resided in nine other counties--Kings (Brooklyn), New York (Manhattan), and Queens counties in New York; Hudson, Passaic, Monmouth, Morris, and Bergen counties in New Jersey; and Fairfield County in Connecticut. Because ill persons represent only a fraction of the persons who are infected, many more persons probably were infected in 2000. To determine the prevalence of recently acquired WNV infection and associated risk factors for infection, random household cluster serosurveys were conducted in Staten Island and portions of Fairfield County, Connecticut, and Suffolk County, New York, during October-November 2000. All three areas had intense WNV epizootics as determined by avian mortality and mosquito surveillance systems. This report summarizes the preliminary results of this survey and indicates that in areas with intense epizootic WNV activity, asymptomatic or mildly symptomatic human infections can occur.


Anonymous. West Nile virus activity--eastern United States, 2001. MMWR Morbidity and Mortality Weekly Report. 2001 Jul 27; 50(29): 617-9. ISSN: 0149-2195.

NAL Call No.: RA407.3 M56

Descriptors:   ArboNET surveillance system data, epidemiology, birds, Culex mosquitoes, mammals, viral isolation and purification, Mid-Atlantic region.

Abstract: In 2000, ArboNET, an enhanced human and animal surveillance system designed to monitor the geographic spread of West Nile virus (WNV) in the United States and to identify areas at increased risk for human infections with WNV, detected WNV activity in the District of Columbia and 12 states. This system, first implemented in the District of Columbia and 20 states along the Atlantic and Gulf coasts, was later expanded throughout the continental United States. This report summarizes ArboNET data from January 1 through July 25, 2001, which documents epizootic WNV activity in the southeast and indicates the need for widespread implementation of WNV prevention activities.


Anonymous. West Nile virus infection may be greater than previously thought. FDA Consumer. 2001 Sep-Oct; 35(5): 8. ISSN:  0362-1332.

NAL Call No.: HD9000.9 U5A1

Descriptors:   viral pathogenecity, disease prevalence, pathogenecity, epidemiology, New York.  


Anomymous. Proceedings of the International Conference on West Nile virus. April 5-7, 2001. White Plains, New York, USA. Annals of the New York Academy of Sciences. 2001 Dec; 951: 1-374. ISSN: 0077-8923.

NAL Call No.: 500 N484 

Descriptors:   West Nile fever epidemiology, prevention and control, transmission, humans and animal species affected.


Arroyo, J; Miller, C A; Catalan, J; Monath, T P. Yellow fever vector live-virus vaccines: West Nile virus vaccine development. Trends in Molecular Medicine. 2001 Aug; 7(8): 350-4. ISSN: 1471-4914.

Descriptors: gene sequence modification on viral function, attenuated live virus as a vaccine candidate, recombinant technology, proteins, therapeutic use, adverse effects, immunology.  

Abstract: By combining molecular-biological techniques with our increased understanding of the effect of gene sequence modification on viral function, yellow fever 17D, a positive-strand RNA virus vaccine, has been manipulated to induce a protective immune response against viruses of the same family (e.g. Japanese encephalitis and dengue viruses). Triggered by the emergence of West Nile virus infections in the New World afflicting humans, horses and birds, the success of this recombinant technology has prompted the rapid development of a live-virus attenuated candidate vaccine against West Nile virus.


Asnis, D S; Conetta, R; Waldman, G; Teixeira, A A. The West Nile virus encephalitis outbreak in the United States (1999-2000): from Flushing, New York, to beyond its borders. Annals of the New York Academy of Sciences. 2001 Dec; 951: 161-71. ISSN: 0077-8923.

NAL Call No.: 500 N484 

Descriptors:  disease history in Western Hemisphere; flavivirus; endemic in Africa and Middle East, and S.W. Asia; New York City outbreak, epidemiology.

Abstract: Viruses cause most forms of encephalitis. The two main types responsible for epidemic encephalitis are enteroviruses and arboviruses. The City of New York reports about 10 cases of encephalitis yearly. Establishing a diagnosis is often difficult. In August 1999, a cluster of five patients with fever, confusion, and weakness were admitted to a community hospital in Flushing, New York. Flaccid paralysis developed in four of the five patients, and they required ventilatory support. Three, less severe, cases presented later in the same month. An investigation was conducted by the NewYork City (NYC) and New York State (NYS) health departments and the national Centers for Disease Control and Prevention (CDC). The West Nile virus (WNV) was identified as the etiologic agent. WNV is an arthropod-borne flavivirus, with a geographic distribution in Africa, the Middle East, and southwestern Asia. It has also been isolated in Australia and sporadically in Europe but never in the Americas. The majority of people infected have no symptoms. Fever, severe myalgias, headache, conjunctivitis, lymphadenopathy, and a roseolar rash can occur. Rarely, encephalitis or meningitis is seen. The NYC outbreak resulted in the first cases of WNV infection in the Western Hemisphere and the first arboviral infection in NYC since yellow fever in the nineteenth century. The WNV is now a public health concern in the United States.


Beasley, D W; Li, L; Suderman, M T; Barrett, A D. West Nile virus strains differ in mouse neurovirulence and binding to mouse or human brain membrane receptor preparations. Annals of the New York Academy of Sciences. 2001 Dec; 951: 332-5. ISSN: 0077-8923.

NAL Call No.: 500 N484

Descriptors:   viral proteins, genetics, mouse brain tissue sampling, neuropathology, virulence, receptor binding, mouse model, humans, molecular sequence data. 


Beck, BR. Hermann Feldmeier: West-Nile-virus ante portas. [Comment on Hermann Feldmeier: West Nile virus ante portas] Schweizerische Rundschau fur Medizin Praxis Revue Suisse de Medecine. 2001 Jan 25; 90(4): 127. ISSN: 1013-2058. Letter in German.

Descriptors: viral horse diseases, virus isolation and purification.


Bernard, K.A.; Kramer, L.D. West Nile virus activity in the United States, 2001. Viral Iimmunology. 2001; 14(4): 319-38. ISSN: 0882-8245.

Descriptors: review article, viral ecology, pathobiology and physiology, transmission patterns, vectors, reservoirs, epidemic comparisons, other arboviruses, vector transmission cycles.

Abstract: West Nile virus (WNV) first appeared in the naive environment of the Western Hemisphere in 1999 in New York. Genetic analysis determined that the virus was introduced into the United States from the Mediterranean Basin. This review discusses the spread of the virus in 2001 from the initial focus in Queens, New York, to widespread activity in the eastern and midwestern United States. It concentrates on viral ecology, epizootiology, pathology, prediction, and prevention. Research questions to further our understanding of the transmission cycle of WNV are discussed, including host-preference studies, molecular confirmation of implicated mosquito vectors, and survival of WNV in the temperate environment of the United States. Comparisons are drawn with two other arboviruses enzootic in the United States, eastern equine encephalitis, and St. Louis encephalitis viruses. Although not recently introduced, these two viruses also demonstrated increased activity in the United States in 2001.


Bernard, K A; Maffei, J G; Jones, S A; Kauffman, E B; Ebel, G; Dupuis, A P 2nd; Ngo, K A; Nicholas, D C; Young, D M; Shi, P Y; Kulasekera, V L; Eidson, M; White, D J; Stone, W B; Kramer, L D. West Nile virus infection in birds and mosquitoes, New York State, 2000. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 679-85. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Abstract: West Nile (WN) virus was found throughout New York State in 2000, with the epicenter in New York City and surrounding counties. We tested 3,403 dead birds and 9,954 mosquito pools for WN virus during the transmission season. Sixty-three avian species, representing 30 families and 14 orders, tested positive for WN virus. The highest proportion of dead birds that tested positive for WN virus was in American Crows in the epicenter (67% positive, n=907). Eight mosquito species, representing four genera, were positive for WN virus. The minimum infection rate per 1,000 mosquitoes (MIR) was highest for Culex pipiens in the epicenter: 3.53 for the entire season and 7.49 for the peak week of August 13. Staten Island had the highest MIR (11.42 for Cx. pipiens), which was associated with the highest proportion of dead American Crows that tested positive for WN virus (92%, n=48) and the highest number of human cases (n=10).

Descriptors:   mortality in bird species, susceptibility of birds, mosquito pools, Culex pipiens, Aedes, Anopheles, New York epidemiology, American crows mortality, transmission and spread of disease to humans and animals   


Borowski, P; Niebuhr, A; Mueller, O; Bretner, M; Felczak, K; Kulikowski, T; Schmitz, H. Purification and characterization of West Nile virus nucleoside triphosphatase (NTPase)/helicase: evidence for dissociation of the NTPase and helicase activities of the enzyme. Journal of Virology. 2001 Apr; 75(7): 3220-9. ISSN:  0022-538X.

NAL Call No.: QR360.J6

Descriptors:   viral genetics, enzyme molecular structure, ATPase, acid anhydride, hydrolases, viral isolation and purification, Vero cells, RNA helicases, adenosine triphosphate pharmacology, Cercopithecus-aethiops, guanine, Vero cells

Abstract: The nucleoside triphosphatase (NTPase)/helicase associated with nonstructural protein 3 of West Nile (WN) virus was purified from cell culture medium harvested from virus-infected Vero cells. The purification procedure included sequential chromatography on Superdex-200 and Reactive Red 120 columns, followed by a concentration step on an Ultrogel hydroxyapatite column. The nature of the purified protein was confirmed by immunoblot analysis using a WN virus-positive antiserum, determination of its NH(2) terminus by microsequencing, and a binding assay with 5'-[(14)C]fluorosulfonylbenzoyladenosine. Under optimized reaction conditions the enzyme catalyzed the hydrolysis of ATP and the unwinding of the DNA duplex with k(cat) values of 133 and 5.5 x 10(-3) s(-1), respectively. Characterization of the NTPase activity of the WN virus enzyme revealed that optimum conditions with respect to the Mg(2+) requirement and the monovalent salt or polynucleotide response differed from those of other flavivirus NTPases. Initial kinetic studies demonstrated that the inhibition (or activation) of ATPase activity by ribavirin-5'-triphosphate is not directly related to changes in the helicase activity of the enzyme. Further analysis using guanine and O(6)-benzoylguanine derivatives revealed that the ATPase activity of WN virus NTPase/helicase may be modulated, i.e., increased or reduced, with no effect on the helicase activity of the enzyme. On the other hand the helicase activity could be modulated without changing the ATPase activity. Our observations show that the number of ATP hydrolysis events per unwinding cycle is not a constant value.


Brinton, MA. Host factors involved in West Nile virus replication. Annals of the New York Academy of Sciences. 2001 Dec; 951: 207-19. ISSN: 0077-8923.

NAL Call No.: 500 N484 

Descriptors:   post viral replication factors, cell proteins in host, viral RNA promoters, protein isolation and purification, birds, Culicidae, mammals, birds, mice, disease susceptibility, carrier proteins, RNA binding-Proteins, West Nile virus genetics.

Abstract: Viruses use cell proteins during many stages of their replication cycles, including attachment, entry, translation, transcription/replication, and assembly. Mutations in the cell proteins involved can cause disruptions of these critical host-virus interactions, which in turn can affect the efficiency of virus replication. These host-virus interactions also represent novel targets for the development of new antiviral agents. The different alleles of the murine Flv gene confer resistance or susceptibility to flavivirus-induced disease and provide a natural mutant system for the study of a host protein that can alter the outcome of a flavivirus infection. Since flaviviruses, such as West Nile virus, replicate in mosquitoes, mammals, and birds during their natural transmission cycles, it is expected that the critical cell proteins used by these viruses will be ones that are highly conserved between divergent host species. Our laboratory has focused on the identification and characterization of the flavivirus resistance gene product and of cell proteins that interact with the 3' terminal regions of the West Nile virus genomic and antigenomic RNAs. The 3' terminal regions of the viral RNAs function as promotors for viral RNA replication. Cell proteins that bind to the viral 3' RNAs were detected by gel shift and UV-induced cross-linking assays. Individual proteins were then purified and partially sequenced. Mutation of a mapped, protein-binding site within the 3' terminal region of the viral RNA in an infectious West Nile virus clone was used to demonstrate the functional importance of one of the cell proteins for efficient West Nile virus replication. Data from additional studies suggested possible roles for this viral RNA-cell protein interaction during the flavivirus replication cycle.


Bunning, M L; Bowen, R A; Cropp, B; Sullivan, K; Davis, B; Komar, N; Godsey, M; Baker, D; Hettler, D; Holmes, D; Mitchell, C J. Experimental infection of horses with West Nile virus and their potential to infect mosquitoes and serve as amplifying hosts. Annals of the New York Academy of Sciences. 2001 Dec; 951: 338-9. ISSN: 0077-8923.

NAL Call No.: 500 N484 

Descriptors: Aedes mosquito as disease, vectors, transmission of horse diseases, virology,  pathogenicity, amplifying of viral disease, immunologic response.


Byrne, S N; Halliday, G M; Johnston, L J; King, N J. Interleukin-1beta but not tumor necrosis factor is involved in West Nile virus-induced Langerhans cell migration from the skin in C57BL/6 mice. Journal of Investigative Dermatology. 2001 Sep; 117(3): 702-9. ISSN:  0022-202X.

NAL Call No.: 448.8 J8292 

Descriptors: interleukin-1 immunology, Langerhans cells, skin, tumor necrosis factor, cell movement, experimental infection in a mouse model, draining lymph, flow cytometry.

Abstract: Langerhans cells are bone marrow-derived epidermal dendritic cells. They migrate out of the epidermis into the lymphatics and travel to the draining lymph nodes where they are responsible for the activation of T cells in the primary immune response. Tumor necrosis factor and interleukin-1beta, have previously been shown to be responsible for Langerhans cell migration in response to contact sensitizers in BALB/C mice; however, which cytokines are responsible for mediating Langerhans cell migration in response to a replicating cutaneously acquired virus such as the West Nile virus, are not known. We have devised a method for identifying Langerhans cells in the draining lymph nodes using E-cadherin labeling and flow cytometry. We infected tumor necrosis factor-deficient gene knockout mice (tumor necrosis factor-/-) intradermally with West Nile virus and found that levels of Langerhans cell emigration and accumulation in the draining lymph nodes were similar to wild-type C57BL/6 mice. This was borne out by the finding that high levels of systemic neutralizing anti-tumor necrosis factor antibody failed to inhibit the migration of Langerhans cells from the epidermis and their accumulation in the draining lymph nodes in wild-type C57BL/6 mice. In West Nile virus-infected, tumor necrosis factor-/- mice treated with systemic neutralizing anti-interleukin-1beta antibodies, however, migration of Langerhans cells from the epidermis and their accumulation in the draining lymph nodes were significantly inhibited compared with control antibody-treated, infected animals. The results indicate that Langerhans cell migration, accumulation in the draining lymph nodes and the initiation of lymph node shut-down in response to a cutaneous West Nile virus infection is dependent on interleukin-1beta and can occur in the absence of tumor necrosis factor.


Campbell, G L; Grady, L J; Huang, C; Lanciotti, R; Kramer, L; Roehrig, J T; Shope, R E.  Laboratory testing for West Nile virus: panel discussion. Annals of the New York Academy of Sciences. 2001 Dec; 951: 179-94. ISSN: 0077-8923.

NAL Call No.: 500 N484 

Descriptors: West Nile virus, diagnosis, immunology, blood antigens, ELISA, reverse transcriptase PCR, epidemiology, viral genetics, viral isolation and purification.


Cannon, C E; Pavlin, J A; Vaeth, M F; Ludwig, G V; Writer, J V; Pagac, B B; Goldenbaum, M B; Kelley, P W. Department of Defense West Nile virus surveillance. Annals of the New York Academy of Sciences. 2001 Dec; 951: 340-2. ISSN: 0077-8923.

NAL Call No.: 500 N484 

Descriptors:  U.S. Department of Defense, surveillance program, epidemiology, ELISA assay, mammals, humans, Culicidae, vector virology, U.S.


Cantile, C.; F. Del Piero; G. Di Guardo; M. Arispici. Pathologic and immunohistochemical findings in naturally occurring West Nile virus infection in horses. Veterinary Pathology. July 2001. v. 38 (4) p. 414-421. ISSN: 0300-9858.

NAL call no:  41.8 P27

Descriptors: horses, West Nile virus, West Nile fever, pathology, lesions, immunohistochemistry, animal tissues, viral antigens, phenotypes, central nervous system, organs, USA, Italy.


Carlson, RH.  West Nile virus in the USA--an update. Lancet Infectious Diseases. 2001 Oct; 1(3): 143. ISSN: 1473-3099.

Descriptors:  epidemiology, disease vectors, disease reservoirs, transmission factors, bird migration, disease spread, U.S.


Ceianu, C S; Ungureanu, A; Nicolescu, G; Cernescu, C; Nitescu, L; Tardei, G; Petrescu, A; Pitigoi, D; Martin, D; Ciulacu Purcarea, V; Vladimirescu, A; Savage, H M. West nile virus surveillance in Romania: 1997-2000. Viral Immunology.

2001; 14(3): 251-62. ISSN: 0882-8245.

Descriptors:  West Nile virus immunology, sentinel surveillance, wild bird diseases, humans, Culex mosquito virology, domestic fowl, seasonal persistence.

Abstract: In response to the 1996 West Nile (WN) fever epidemic that occurred in Bucharest and southeastern Romania, a surveillance program was established. The surveillance system detected 39 clinical human WN fever cases during the period 1997-2000: 14 cases in 1997, 5 cases in 1998, 7 cases in 1999, and 13 cases in 2000. Thirty-eight of the 39 case-patients lived in the greater Danube Valley of southern Romania, and 1 case-patient resided in the district of Vaslui, located on the Moldavian plateau. The estimated annual case incidence rate for the surveillance area during the period 1997-2000 was 0.95 cases per million residents. Thirty-four cases were serologically confirmed, and 5 cases were classified as probable. Twenty-four case-patients presented with clinical symptoms of meningitis (62%), 12 with meningoencephalitis (31%), 1 with encephalitis (3%), and 2 with febrile exanthema (5%). Five of the 39 cases were fatal (13%). Fourteen case-patients resided in rural areas, and 25 in urban and suburban areas, including 7 case-patients who resided in Bucharest. The ages of case-patients ranged from 8 to 76 years with a median age of 45 years. Twenty-four case-patients were males and 15 were females. Dates of onset of illness occurred from May 24 through September 25, with 82% of onset dates occurring in August and September. Limited entomological surveillance failed to detect WN virus. Retrospective sampling of domestic fowl in the vicinity of case-patient residences during the years 1997-2000 demonstrated seroprevalence rates of 7.8%-29%. Limited wild bird surveillance demonstrated seroprevalence rates of 5%-8%. The surveillance data suggest that WN virus persists focally for several years in poorly understood transmission cycles after sporadic introductions or that WN virus is introduced into Romania at relatively high rates, and persists seasonally in small foci.


Cherry, B; Trock, S C; Glaser, A; Kramer, L; Ebel, G D; Glaser, C; Miller, J R. Sentinel chickens as a surveillance tool for West Nile virus in New York City, 2000. Annals of the New York Academy of Sciences. 2001 Dec; 951: 343-6. ISSN: 0077-8923.

NAL Call No.: 500 N484 

Descriptors:  disease incidence, disease monitoring, chickens as sentinel animals, domestic fowl, disease prevention and control, ELISA, predictive value of tests, immunology.


Covello, V T; Peters, R G; Wojtecki, J G; Hyde, R C. Risk communication, the West Nile virus epidemic, and bioterrorism: responding to the communication challenges posed by the intentional or unintentional release of a pathogen in an urban setting. Journal of Urban Health Bulletin of the New York Academy of Medicine. 2001 Jun; 78(2): 382-91. ISSN:  1099-3460.

Descriptors: disease risk assessment communication, theoretical perspective, risk communication models, communication management, bioterrorism psychology, New York City.

Abstract: The intentional or unintentional introduction of a pathogen in an urban setting presents severe communication challenges. Risk communication--a science-based approach for communicating effectively in high-concern situations--provides a set of principles and tools for meeting those challenges. A brief overview of the risk communication theoretical perspective and basic risk communication models is presented here, and the risk communication perspective is applied to the West Nile virus epidemic in New York City in 1999 and 2000 and to a possible bioterrorist event. The purpose is to provide practical information on how perceptions of the risks associated with a disease outbreak might be perceived and how communications would be best managed.


Craven, R B; Roehrig, J T. West Nile virus. JAMA -- The Journal of the American Medical Association. 2001 Aug 8; 286(6): 651-3. ISSN: 0098-7484.

NAL Call No.: 448.9 Am37

Descriptors:  disease diagnosis, epidemiology, disease prevention and control, birds, insect vectors, Culicidae, viral isolation and purification, therapy.  


Davis, B S; Chang, G J; Cropp, B; Roehrig, J T; Martin, D A; Mitchell, C J; Bowen, R; Bunning, M L. West Nile virus recombinant DNA vaccine protects mouse and horse from virus challenge and expresses in vitro a noninfectious recombinant antigen that can be used in enzyme-linked immunosorbent assays. Journal of Virology. 2001 May; 75(9): 4040-7. ISSN:  0022-538X.

NAL Call No.: QR360.J6

Descriptors: intramuscular administration of vaccines, recombinant plasmid expressing WN virus prM and E proteins, efficacy in mice and horses, anitigen form cell culture, disease prevention and control.

Abstract: Introduction of West Nile (WN) virus into the United States in 1999 created major human and animal health concerns. Currently, no human or veterinary vaccine is available to prevent WN viral infection, and mosquito control is the only practical strategy to combat the spread of disease. Starting with a previously designed eukaryotic expression vector, we constructed a recombinant plasmid (pCBWN) that expressed the WN virus prM and E proteins. A single intramuscular injection of pCBWN DNA induced protective immunity, preventing WN virus infection in mice and horses. Recombinant plasmid-transformed COS-1 cells expressed and secreted high levels of WN virus prM and E proteins into the culture medium. The medium was treated with polyethylene glycol to concentrate proteins. The resultant, containing high-titered recombinant WN virus antigen, proved to be an excellent alternative to the more traditional suckling-mouse brain WN virus antigen used in the immunoglobulin M (IgM) antibody-capture and indirect IgG enzyme-linked immunosorbent assays. This recombinant antigen has great potential to become the antigen of choice and will facilitate the standardization of reagents and implementation of WN virus surveillance in the United States and elsewhere.


Deubel, V; Gubler, D J; Layton, M; Malkinson, M. West Nile virus: a newly emergent epidemic disease. Emerging Infectious Diseases. 2001; 7(3 Suppl): 536. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:  emerging disease epidemiology, Culex mosquitoes virology, disease prevention and control, birds as disease reservoirs, epidemiology, role of migratory birds.


Dohm, D.J.; M. Turell. Effect of incubation at overwintering temperatures on the replication of West Nile virus in New York Culex pipiens (Diptera: Culicidae). Journal of Medical Entomology. May 2001. v. 38 (3) p. 462-464. ISSN: 0022-2585.

NAL call no:  421 J828

Descriptors: Culex pipiens, West Nile virus, disease vectors, experimental infections, mosquitoes, viral replication, disseminated infections, overwintering, environmental temperature, simulation, New York.

Abstract: We examined the effect of simulated overwintering temperatures on West Nile (WN) virus replication in Culex pipiens L. derived from mosquitoes collected during the autumn 1999 WN epizootic in New York. The WN virus was a strain isolated from a dead crow also collected during this outbreak. Virus was recovered from most mosquitoes held exclusively at 26 degrees C. In contrast, none of the mosquitoes held exclusively at the lower temperatures had detectable infections. When mosquitoes were transferred to 26 degrees C after being held at 10 degrees C for 21-42 d, infection and dissemination rates increased with increased incubation at 26 degrees C. Future studies involving the attempted isolation of WN virus from overwintering mosquitoes may benefit from holding the mosquitoes at 26 degrees C before testing for infectious virus.


Ebel, G D; Dupuis, A P 2nd; Ngo, K; Nicholas, D; Kauffman, E; Jones, S A; Young, D; Maffei, J; Shi, P Y; Bernard, K; Kramer, L D. Partial genetic characterization of West Nile virus strains, New York State, 2000. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 650-3. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors: viral strains analysis, envelope genes, nucleotide sequences, reverse transcriptase PCR, viral amplification methodologies, genetic differences.

Abstract: We analyzed nucleotide sequences from the envelope gene of 11 West Nile (WN) virus strains collected in New York State during the 2000 transmission season to determine whether they differed genetically from each other and from the initial strain isolated in 1999. The complete envelope genes of these strains were amplified by reverse transcription-polymerase chain reaction. The resulting sequences were aligned, the genetic distances were computed, and a phylogenetic tree was constructed. Ten (0.7%) of 1,503 positions in the envelope gene were polymorphic in one or more sequences. The genetic distances were 0.003 or less. WN virus strains circulating in 2000 were homogeneous with respect to one another and to a strain isolated in 1999.  


Eidson, M "Neon needles" in a haystack: the advantages of passive surveillance for West Nile virus. Annals of the New York Academy of Sciences. 2001 Dec; 951: 38-53. ISSN: 0077-8923.

NAL Call No.: 500 N484 

Descriptors:  disease reservoirs, epidemiology, population surveillance, crow mortality rates, virus levels, correlation of dead crows to human disease. 

Abstract: Passive surveillance is usually viewed as less efficient for case ascertainment than active surveillance. However, for diseases with nonhuman animal reservoirs, active surveillance can be like looking for a needle in a haystack and may be prohibitively expensive. Fortunately for surveillance of West Nile virus (WNV) in the northeast US, the dead crows have served as "neon needles in a haystack"--indicators of viral activity that call attention to themselves. In 2000, laboratory testing of dead birds, including all species, birds found singly, with signs of trauma, or no compatible pathology, provided the first confirmation of viral activity in most areas. The surveillance factor most closely associated with the number of human cases was the dead crow density. In 2001, dead crow densities will be used as an additional index for monitoring human risk and need for prevention and control activities. If there are few crows in an area, if their case-fatality rate is reduced, or if there is public complacency about reporting dead crow sightings, this passive surveillance indicator may not be helpful in identifying areas likely to have occasional human cases or an outbreak.


Eidson, M; Komar, N; Sorhage, F; Nelson, R; Talbot, T; Mostashari, F; McLean, R. Crow deaths as a sentinel surveillance system for West Nile virus in the northeastern United States, 1999. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 615-20. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:  virus prevalence, surveillance, songbirds, dead crows as indicators of viral activity, relationship of bird mortality to human cases, disease reservoir, geographic distribution, New Jersey, New York, Connecticut.

Abstract: In addition to human encephalitis and meningitis cases, the West Nile (WN) virus outbreak in the summer and fall of 1999 in New York State resulted in bird deaths in New York, New Jersey, and Connecticut. From August to December 1999, 295 dead birds were laboratory-confirmed with WN virus infection; 262 (89%) were American Crows (Corvus brachyrhynchos). The New York State Department of Health received reports of 17,339 dead birds, including 5,697 (33%) crows; in Connecticut 1,040 dead crows were reported. Bird deaths were critical in identifying WN virus as the cause of the human outbreak and defining its geographic and temporal limits. If established before a WN virus outbreak, a surveillance system based on bird deaths may provide a sensitive method of detecting WN virus.


Eidson, M; Kramer, L; Stone, W; Hagiwara, Y; Schmit, K. Dead bird surveillance as an early warning system for West Nile virus. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 631-5. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors: early detection, virus surveillance system, dead diseased crows, songbirds, correlation between bird deaths and human disease, mosquito vector control, predictive value of tests, sentinel surveillance, New York.

Abstract: As part of West Nile (WN) virus surveillance in New York State in 2000, 71,332 ill or dead birds were reported; 17,571 (24.6%) of these were American Crows. Of 3,976 dead birds tested, 1,263 (31.8%) were positive for WN virus. Viral activity was first confirmed in 60 of the state's 62 counties with WN virus-positive dead birds. Pathologic findings compatible with WN virus were seen in 1,576 birds (39.6% of those tested), of which 832 (52.8%) were positive for WN virus. Dead crow reports preceded confirmation of viral activity by several months, and WN virus-positive birds were found >3 months before the onset of human cases. Dead bird surveillance appears to be valuable for early detection of WN virus and for guiding public education and mosquito control efforts.


Eidson, M; Miller, J; Kramer, L; Cherry, B; Hagiwara, Y. Dead crow densities and human cases of West Nile virus, New York State, 2000. Emerging Infectious Diseases. 2001 Jul Aug; 7(4): 662 4. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors: epidemiolgy, monitoring of dead crow densities, viral levels, correlation with human cases, specimen collection and testing, disease reservoirs, New York City.

Abstract: In 2000, Staten Island, New York, reported 10 human West Nile virus cases and high densities of dead crows. Surrounding counties with <2 human cases had moderate dead crow densities, and upstate counties with no human cases had low dead crow densities. Monitoring such densities may be helpful because this factor may be determined without the delays associated with specimen collection and testing.  


Epstein, P R. West Nile virus and the climate. Journal of Urban Health Bulletin of the New York Academy of Medicine. 2001 Jun; 78(2): 367-71. ISSN: 1099-3460.

Descriptors:  factors affecting survival and disease spread, urban dwelling birds and mosquitoes, effect of warm winters and spring drought, vector control measures, breeding places, climatic change, mosquito borne diseases, ovicides and larvicides, North America.

Abstract: West Nile virus is transmitted by urban-dwelling mosquitoes to birds and other animals, with occasional "spillover" to humans. While the means by which West Nile virus was introduced into the Americas in 1999 remain unknown, the climatic conditions that amplify diseases that cycle among urban mosquitoes, birds, and humans are warm winters and spring droughts. This information can be useful in generating early warning systems and mobilizing timely and the most environmentally friendly public health interventions. The extreme weather conditions accompanying long-term climate change may also be contributing to the spread of West Nile virus in the United States and Europe.


Farello, C A; Sorhage, F E; Bresnitz, E A; Grant, C. West Nile virus: New Jersey's 2000 experience and surveillance plans for 2001. New Jersey Medicine the Journal of the Medical Society of New Jersey. 2001 Jul; 98(7): 25-32.

ISSN: 0885-842X.

Descriptors:  viral prevelance and dead birds surveillance program, transmission patterns, disease prevention and control, virus isolation and purification, New Jersey.


Garmendia, A E; Van Kruiningen, H J; French, R A. The West Nile virus: its recent emergence in North America. Microbes and Infection Institut Pasteur. 2001 Mar; 3(3): 223-9. ISSN:  1286-4579.

NAL Call No.: QR180 M53

Descriptors:   review article, history of disease emergence starting in 1999, humans, horses, wild birds, correlation between human disease and bird mortality, mosquito vectors, Chiroptera virology, bats, Culicidae virology, surveillance data.

Abstract: West Nile fever emerged in New York in the summer of 1999 when seven people, several horses and thousands of wild birds died. It was soon established that the human disease and the mortality of birds were related. Continued surveillance detected West Nile virus in mosquitoes, birds, horses, small mammals, bats and humans, and has shown its spread to several northeastern states. These events confirm the establishment of West Nile virus endemically in the United States.


Gotham, I J; Eidson, M; White, D J; Wallace, B J; Chang, H G; Johnson, G S; Napoli, J P; Sottolano, D L; Birkhead, G S; Morse, D L; Smith, P F.   West Nile virus: a case study in how NY State Health Information infrastructure facilitates preparation and response to disease outbreaks. Journal of Public Health Management and Practice. 2001 Sep; 7(5): 75-86. ISSN: 1078-4659  

Descriptors:   New York State Health Information Network, integrated surveillance system, humans, birds, other mammals, mosquitoes, tracking, retrieval of data on disease outbreaks, disaster planning, communication plans.  

Abstract: New York's (NY) Health Information Network (HIN) provided timely access to West Nile virus (WNV) data during the initial outbreak in the late Summer 1999. In December 1999, NY developed a plan to deal with WNV in 2000 that required an integrated surveillance system for humans, birds, mammals, and mosquitoes. The HIN infrastructure allowed NY to deploy this system statewide in three months. Local health departments throughout NY used the system to report, track, and retrieve surveillance data as WNV spread throughout NY in 2000. The HIN infrastructure includes partnerships, training/support, technical capacity and architecture similar to NEDSS as proposed by the US CDC.


Groot, de A S; Saint Aubin, C; Bosma, A; Sbai, H; Rayner, J; Martin, W.  Rapid determination of HLA B*07 ligands from the West Nile virus NY99 genome. Emerging Infectious Diseases. 2001 Jul Aug; 7(4): 706 13. ISSN: 1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:  T lymphocyte epitopes, subunit vaccine development, genome mapping, rapid and inexpensive methodologies, ligands useful for cell-mediated response, possible diagnostic reagents.

Abstract: Defined T cell epitopes for West Nile (WN) virus may be useful for developing subunit vaccines against WN virus infection and diagnostic reagents to detect WN virus-specific immune response. We applied a bioinformatics (EpiMatrix) approach to search the WN virus NY99 genome for HLA B*07 restricted cytotoxic T cell (CTL) epitopes. Ninety-five of 3,433 WN virus peptides scored above a predetermined cutoff, suggesting that these would be likely to bind to HLA B*07 and would also be likely candidate CTL epitopes. Compared with other methods for genome mapping, derivation of these ligands was rapid and inexpensive. Major histocompatibility complex ligands identified by this method may be used to screen T cells from WN virus-exposed persons for cell-mediated response to WN virus or to develop diagnostic reagents for immunopathogenesis studies and epidemiologic surveillance.


Hadfield, T L; Turell, M; Dempsey, M P; David, J; Park, E J. Detection of West Nile virus in mosquitoes by RT-PCR. Molecular and Cellular Probes. 2001 Jun; 15(3): 147-50. ISSN: 0890-8508.

NAL Call No.: 0890-8508

Descriptors:   reverse transcriptase PCR assay, TaqMan, viral assay method, infected mosquitoes, eastern equine encephalitis virus, Ilheus virus, yellow fever virus, level of accuracy. 

Abstract: A reverse transcriptase-polymerase chain reaction (RT-PCR) assay employing <<TaqMan>> detection technology was developed to identify West Nile virus in experimentally infected mosquitoes. The specificity of the assay was evaluated with the following viruses: eastern equine encephalitis, Ilheus, West Nile and yellow fever viruses. The limits of detection were determined using West Nile viral RNA extracted from serial dilutions of virus culture in infected mosquitoes. Limit of detection was 5 PFU from extracted mosquitoes. We were able to detect the presence of one infected mosquito in a pool of 50 repeatedly. When the RT-PCR was used with coded samples of intrathoracically-infected and uninfected mosquitoes, the assay detected the virus in all infected mosquitoes. Analytic sensitivity and specificity were 100%. This assay offers an efficient and rapid method of identifying West Nile virus in infected mosquitoes or cell culture.


Hadler, J; Nelson, R; McCarthy, T; Andreadis, T; Lis, M J; French, R; Beckwith, W; Mayo, D; Archambault, G; Cartter, M. West Nile virus surveillance in Connecticut in 2000: an intense epizootic without high risk for severe human disease.

Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 636-42. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   monitoring bird deaths, testing dead crows and songbirds, horse disease levels, trapping and testing mosquitoes, human seropervalance survey, animal sentinel surveillance, Culex virology, insect vector monitoring, Connecticut.

Abstract: In 1999, Connecticut was one of three states in which West Nile (WN) virus actively circulated prior to its recognition. In 2000, prospective surveillance was established, including monitoring bird deaths, testing dead crows, trapping and testing mosquitoes, testing horses and hospitalized humans with neurologic illness, and conducting a human seroprevalence survey. WN virus was first detected in a dead crow found on July 5 in Fairfield County. Ultimately, 1,095 dead crows, 14 mosquito pools, 7 horses, and one mildly symptomatic person were documented with WN virus infection. None of 86 hospitalized persons with neurologic illness (meningitis, encephalitis, Guillain-Barre-like syndrome) and no person in the seroprevalence survey were infected. Spraying in response to positive surveillance findings was minimal. An intense epizootic of WN virus can occur without having an outbreak of severe human disease in the absence of emergency adult mosquito management.


Hayes, C G. West Nile virus: Uganda, 1937, to New York City, 1999. Annals of the New York Academy of Sciences. 2001 Dec; 951: 25-37. ISSN: 0077-8923.

NAL Call No.: 500 N484 

Descriptors:   review article, 3 urban epidemics, risk factors, viral virulence changes, 60 years of observations about West Nile virus, Culex, pathogenicity, New York, Uganda.

Abstract: West Nile virus, first isolated in 1937, is among the earliest arthropod-borne viruses discovered by humans. Its broad geographical distribution, not uncommon infection of humans, transmission by mosquitoes, and association with wild birds as enzootic hosts were well documented by the mid-1960s. However, West Nile virus was not considered to be a significant human pathogen because most infections appeared to result in asymptomatic or only mild febrile disease. Several epidemics had been documented prior to 1996, some involving hundreds to thousands of cases in mostly rural populations, but only a few cases of severe neurological disease had been reported. The occurrence between 1996 and 1999 of three major epidemics, in southern Romania, the Volga delta in southern Russia, and the northeastern United States, involving hundreds of cases of severe neurological disease and fatal infections was totally unexpected. These were the first epidemics reported in large urban populations. A significant factor that appeared in common to all three outbreaks was the apparent involvement of the common house mosquito, Culex pipiens, as a vector. This species had not previously been implicated as important in the transmission of West Nile virus. In addition the epidemic in the northeastern United States was unusual in the association of West Nile virus infection with fatal disease of birds, suggesting a change in the virulence of the virus toward this host. Understanding the risk factors that contributed to these three urban epidemics is important for minimizing the potential for future occurrences. This review will attempt to compare observations on the biology of West Nile virus made over about 60 years prior to the recent epidemics to observations made in association with these urban epidemics.


Hindiyeh, M; Shulman, L M; Mendelson, E; Weiss, L; Grossman, Z; Bin, H. Isolation and characterization of West Nile virus from the blood of viremic patients during the 2000 outbreak in Israel. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 748-50. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   phylogenetic analysis of the West Nile virus, disease outbreaks in Israel in 2000, 2 isolates related to New York isolate and Russian isolate,  RNA viral analysis; reverse transcriptase.   

Abstract: We report the isolation of West Nile (WN) virus from four patient serum samples submitted for diagnosis during an outbreak of WN fever in Israel in 2000. Sequencing and phylogenetic analysis revealed two lineages, one closely related to a 1999 New York isolate and the other to a 1999 Russian isolate.


Hinkle N. Equine cases of West Nile virus from 1 January through 19 September, 2001. Vector Ecology Newsletter. 2001, 32: 3.

Descriptors: survey of West Nile virus in horses, veterinary diseases, disease incidence, Alabama, Connecticut, Florida, Georgia, Kentucky, Louisiana, Massachusetts, New Jersey, Pennsylvania, Virginia.


Hodgson, J.C.; A. Spielman; N. Komar; C. Krahforst; G. Wallace; R. Pollack. Interrupted blood-feeding by Culiseta melanura (Diptera: Culicidae) on European starlings. Journal of Medical Entomology. Jan 2001. v.38 (1) p. 59-66. ISSN: 0022-2585.

NAL call no:  421 J828

Descriptors: Culiseta melanura, mosquitoes, hematophagy, feeding frequency, blood meals, engorgement, volume, Turdus migratorius, Sturnus vulgaris, reservoir hosts, host preferences, animal behavior, defense, disease vectors, eastern equine encephalitis virus, robins, starlings, Massachusetts.

Abstract: To determine whether Culiseta melanura (Coquillett) mosquitoes tend to take multiple blood meals when birds of certain species serve as hosts, we compared the frequencies with which such mosquitoes fed upon caged starlings and robins and determined whether similar volumes of blood were imbibed from each. The blood of robins (Turdus migratorius) and European starlings (Sturnus vulgaris) was marked contrastingly by injecting birds with rubidium or cesium salts. Caged birds were placed together in a natural wetland setting overnight. Mosquitoes captured nearby on the following morning were analyzed for each of the elemental markers. Where marked robins and starlings were equally abundant, 43% of freshly engorged Cs. melanura fed on more than or equal to two hosts. More Cs. melanura fed on robins than on starlings. Individual mosquitoes tended to contain far more robin- than starling-associated marker, indicating that mosquitoes "feasted" on robins but only "nibbled" on starlings. Mosquitoes marked with both elements apparently fed meagerly on the starlings then abundantly on the robins. Our estimates of bloodmeal volume indicate that 85% of mosquitoes that fed on marked starlings obtained <0.5 microliter of blood from them. We suggest that defensive behavior by starlings interrupts mosquito blood-feeding and that, in a communal roost of starlings, each mosquito will tend to feed on more than one bird, thereby promoting rapid transmission of such ornithonotic arboviruses as eastern equine encephalomyelitis virus and West Nile virus.


Johnson, D J; Ostlund, E N; Pedersen, D D; Schmitt, B J.  Detection of North American West Nile virus in animal tissue by a reverse transcription-nested polymerase chain reaction assay. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 739-41. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors: RT nested PCR virus detection method, bird tissue samples, infected cell cultures, sensitivity to detection of virus in equine tissues.

Abstract: A traditional single-stage reverse transcription-polymerase chain reaction (RT-PCR) procedure is effective in determining West Nile (WN) virus in avian tissue and infected cell cultures. However, the procedure lacks the sensitivity to detect WN virus in equine tissue. We describe an RT-nested PCR (RT-nPCR) procedure that identifies the North American strain of WN virus directly in equine and avian tissues.


Jupp, PG. The ecology of West Nile virus in South Africa and the occurrence of outbreaks in humans. Annals of the New York Academy of Sciences. 2001 Dec; 951: 143-52.ISSN: 0077-8923.

NAL Call No.: 500 N484

Descriptors:  review paper, research/studies in South Africa’s inland plateau, epizootic transmission cycle, mosquitoes, birds as viral reservoirs and disease spreaders, dogs, Culex species, strain causes mild illness in humans, Culex univittatus, Culex theileri, vector mosquitoes.  

Abstract: This paper reviews studies done on West Nile virus (WNV) in South Africa, mainly between 1962 and 1980 on the temperate inland plateau (Highveld and Karoo). The virus is maintained in an enzootic transmission cycle between feral birds and the ornithophilic mosquito Culex univittatus. About 30 avian species have been shown to be involved without mortality. Humans, and other mammals, although they may have antibodies, are considered blind-alleys in the transmission cycle except perhaps some dogs. Cx. univittatus also transfers infection to humans, almost invariably causing only a mild illness. Its usually low anthropophilism may explain why annual human infection on the Highveld is limited to sporadic cases. Besides multiple isolations from field collections of Cx. univittatus, this mosquito is both highly susceptible to the virus and an efficient transmitter. Culex theileri is a minor vector. In the summer of 1974 there was a large epidemic in the dry Karoo after unusual rains: there were many human cases, the infection rate in Cx. univittatus was 39.0/1000, and postepidemic immune rates in humans and birds were high. In 1984 there was an epizootic in Gauteng Province in the Highveld with an infection rate in Cx. univittatus reaching 9.6/1000 and more human infections than usual. The much lower immune rates in the KwaZulu-Natal coastal lowlands than on the plateau and the single isolation from Cx. neavei, which replaces Cx. univittatus in the lowlands, are explained by the low susceptibility of Cx. neavei to the virus. Genetic relatedness of isolates from different countries showed two lineages, with one lineage comprising only African isolates, including 25 South African strains, which had a sequence homology of 86.3-100%. This suggests that the viral enzooticity does not depend on annual importation of virus in migrant birds.


Kallio S; Hanninen ML. West Nile-viruksen aiheuttamat epidemiat: kirjallisuuskatsaus [Epidemics caused by West Nile virus: a literature review.] Suomen Elainlaakarilehti. 2001, 107: 9, 501-504; 11 ref. In Finnish.

NAL Call No.: 41.8 N813

Descriptors:   history of pathogenic virus migration out of the Nile area of Africa, Romania, biology of disease, control of vector mosquitoes, mosquito control via larvae control, transmission factors.  


Kauffman, E B; Bernard, K A; Jones, S A; Maffei, J; Ngo, K; Kramer, L D. West Nile virus laboratory surveillance program: cost and time analysis. Annals of the New York Academy of Sciences. 2001 Dec; 951: 351-3. ISSN: 0077-8923.

NAL Call No.: 500 N484

Descriptors: virology study, economics, epidemiology, isolation and purification, disease prevention and control, viral genetics, disease population surveillance, costs and cost analysis, Culicidae mosquito vectors, reverse transcriptase polymerase chain reaction, viral genetics, New York State program.  


Klimes, J.; Z. Juricova; I. Literak; P. Schanilec; E. Silva. Prevalence of antibodies to tickborne encephalitis and West Nile flaviviruses and the clinical signs of tickborne encephalitis in dogs in the Czech Republic. Veterinary Record. Jan 6, 2001. v. 148 (1) p. 17-20. ISSN: 0042-4900.

NAL call no:  41.8 V641

Descriptors: dogs, tickborne encephalitis virus, seroprevalence, antibodies, tickborne encephalitis, West Nile virus, clinical aspects, cross reaction, rottweiler, Czech Republic.


Komar, N. West Nile virus surveillance using sentinel birds. Annals of the New York Academy of Sciences. 2001 Dec; 951: 58-73. ISSN: 0077-8923.

NAL Call No.: 500 N484 

Descriptors:   monitoring of virus levels, sentinel house sparrows and pigeons, selection of  monitoring sites, Culex pipiens disease vectors. 

Abstract: Captive and free-ranging birds have been used for decades as living sentinels in arbovirus surveillance programs. This review summarizes information relevant to selecting sentinel bird species for use in surveillance of West Nile (WN) virus. Although experience using avian sentinels for WN virus surveillance is limited, sentinels should be useful for both detecting and monitoring WN virus transmission; however, sentinel bird surveillance systems have yet to be adequately tested for use with the North American strain of WN virus. Captive chickens are typically used for arbovirus surveillance, but other captive species may be used as well. Serosurvey and experimental infection data suggest that both chickens and pigeons show promise as useful captive sentinels; both species were naturally exposed during the epizootics in New York City, 1999-2000, and both species develop antibodies after infection without becoming highly infectious to Culex pipiens vectors. Wild bird species that should be targeted for use as free-ranging sentinels include house sparrows and pigeons. The ideal wild bird should be determined locally on the basis of seroprevalence studies. Interpreting serological data generated from studies using free-ranging sentinel birds is complex, however. Sentinel bird monitoring sites should be selected in enzootic transmission foci. Several years of observation may be required for selection of effective sentinel monitoring sites.


Komar, N; Panella, N A; Boyce, E. Exposure of domestic mammals to West Nile virus during an outbreak of human encephalitis, New York City, 1999. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 736-8. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   monitoring of disease in horses, dogs and cats, possible role as sentinels, immunology, neutralization tests, seroepidemiology studies, New York City.

Abstract: We evaluated West Nile (WN) virus seroprevalence in healthy horses, dogs, and cats in New York City after an outbreak of human WN virus encephalitis in 1999. Two (3%) of 73 horses, 10 (5%) of 189 dogs, and none of 12 cats tested positive for WN virus-neutralizing antibodies. Domestic mammals should be evaluated as sentinels for local WN virus activity and predictors of the infection in humans.    


Komar, N; Panella, N A; Burns, J E; Dusza, S W; Mascarenhas, T M; Talbot, T O. Serologic evidence for West Nile virus infection in birds in the New York City vicinity during an outbreak in 1999. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 621-5. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   seropositive songbirds, domestic geese, chickens, house sparrows, Canada geese, rock doves, sentinel animals, viral reservoirs, bood sampling.  

Abstract: As part of an investigation of an encephalitis outbreak in New York City, we sampled 430 birds, representing 18 species in four orders, during September 13-23, 1999, in Queens and surrounding counties. Overall, 33% were positive for West Nile (WN) virus-neutralizing antibodies, and 0.5% were positive for St. Louis encephalitis virus-neutralizing antibodies. By county, Queens had the most seropositive birds for WN virus (50%); species with the greatest seropositivity for WN virus (sample sizes were at least six) were Domestic Goose, Domestic Chicken, House Sparrow, Canada Goose, and Rock Dove. One sampled bird, a captive adult Domestic Goose, showed signs of illness; WN virus infection was confirmed. Our results support the concept that chickens and House Sparrows are good arbovirus sentinels. This study also implicates the House Sparrow as an important vertebrate reservoir host.


Kramer, L D; Bernard, K A West Nile virus in the western hemisphere. Current Opinion in Infectious Diseases. 2001 Oct; 14(5): 519-25. ISSN:  0951-7375

Descriptors:   review article, disease introduction into New York City, disease establishment, transmission biology and cycle, disease vector mosquitoes, prevention and control of spread, invasive species. 

Abstract: West Nile virus first appeared in the western hemisphere in 1999 in New York. Genetic analysis determined that the virus was introduced from the Mediterranean Basin. This review discusses the establishment of West Nile virus in the naive environment of the northeastern USA, its ecology, epizootiology, pathology, prevention and prediction, as well as laboratory studies that have been conducted to elucidate the transmission cycle.


Kramer, L D; Bernard, K A. West Nile virus infection in birds and mammals. Annals of the New York Academy of Sciences. 2001 Dec; 951: 84-93. ISSN: 0077-8923.

NAL Call No.: 500 N484

Descriptors:   dead bird sampling, percentage carrying West Nile virus, highest mortality in crows, kidney viremia levels, experimental infection in mice.  

Abstract: West Nile virus (WNV) was found throughout New York State in year 2000. The epicenter was located in New York City with a high level of activity in the immediately surrounding counties, including Rockland, Westchester, Nassau, and Suffolk. During 2000, WNV testing was performed by the Wadsworth Center on 3,687 dead birds, representing 153 species, 46 families, and 18 orders. There were 1,203 WNV-positive birds, representing 63 species, 30 families and 14 orders. The percentage of WNV-positive birds was 33% for all birds tested throughout the state, with no significant difference in infection rates in migratory versus resident birds, although significantly more resident birds were submitted for testing. The highest apparent mortality for the entire season was observed in American crows in Staten Island, a location that also showed the highest minimal infection rate in Culex pipiens complex mosquitoes. Studies examining tissue tropism of WNV in corvids and noncorvids from the epicenter and from remote locations indicated that the kidney was the most consistently infected tissue in birds, regardless of level of infection. The brain was the next most consistently positive tissue. The differences in infection among the tissues were most apparent when low levels of virus were present. Experimental mouse inoculation demonstrated a classical flavivirus infection pattern.


Krenick, F; Jany, W; Clarke, J L 3rd. Sumithrin: from inception to integration within West Nile virus programs. Annals of the New York Academy of Sciences. 2001 Dec; 951: 354-6. ISSN: 0077-8923.

NAL Call No.: 500 N484

Descriptors:   Culicidae vector mosquito prevention and control, insecticides, pyrethrins, efficacy.


Kulas, K E; Demarest, V L; Franchell, C S; Wong, S J. Use of an arboviral immunofluorescent assay in screening for West Nile virus. Annals of the New York Academy of Sciences. 2001 Dec; 951: 357-60. ISSN: 0077-8923.

NAL Call No.: 500 N484

Descriptors:   fluorescent antibody technique, blood screening diagnostic test, predictive value of test, immunology, West Nile virus diagnosis, isolation and purification. 


Kulasekera, V L; Kramer, L; Nasci, R S; Mostashari, F; Cherry, B; Trock, S C; Glaser, C; Miller, J R. West Nile virus infection in mosquitoes, birds, horses, and humans, Staten Island, New York, 2000. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 722-5. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   disease transition model, Culex pipiens, Culex restuans, primary enzootic and epizootic vectors among birds, Culex salinariun as bridge vector for humans, Aedes/Ochlerotatus as bridge vectors for horse infections. 

Abstract: West Nile (WN) virus transmission in the United States during 2000 was most intense on Staten Island, New York, where 10 neurologic illnesses among humans and 2 among horses occurred. WN virus was isolated from Aedes vexans, Culex pipiens, Cx. salinarius, Ochlerotatus triseriatus, and Psorophora ferox, and WN viral RNA was detected in Anopheles punctipennis. An elevated weekly minimum infection rate (MIR) for Cx. pipiens and increased dead bird density were present for 2 weeks before the first human illness occurred. Increasing mosquito MIRs and dead bird densities in an area may be indicators of an increasing risk for human infections. A transmission model is proposed involving Cx. pipiens and Cx. restuans as the primary enzootic and epizootic vectors among birds, Cx. salinarius as the primary bridge vector for humans, and Aedes/Ochlerotatus spp. as bridge vectors for equine infection.


Lanciotti Robert S; Kerst Amy J; Nasci Roger S; Godsey Marvin S; Mitchell Carl J; Savage Harry M; Komar Nicholas; Panella Nicholas A; Allen Becky C; Volpe Kate E; Davis Brent S; Roehrig John T. Rapid detection of West Nile virus from human clinical specimens, field-collected mosquitoes, and avian samples by a TaqMan reverse transcriptase-PCR assay. Journal of Clinical Microbiology. November, 2001; 38 (11): 4066-4071.  ISSN: 0095-1137.

NAL Call No.: QR46.J6

Descriptors:   rapid TaqMan detection assay, various laboratory and field tested specimens, comparison, reverse transcriptase PCR assay, virus isolation in Vero cells, tissues from humans, wild mosquitoes, bird tissues, surveillance method, surveillance tool, oligonucleotide primers and FAM- and TAMRA-labeled WN virus-specific probes.


Langevin, S A; Bunning, M; Davis, B; Komar, N. Experimental infection of chickens as candidate sentinels for West Nile virus. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 726-9. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   duration and level of viremia, serology, chickens, experimental infections, needle and oral inoculations, sentinel species, antibody levels, vector mosquitoes.

Abstract: We evaluated the susceptibility, duration and intensity of viremia, and serologic responses of chickens to West Nile (WN) virus (WNV-NY99) infection by needle, mosquito, or oral inoculation. None of 21 infected chickens developed clinical disease, and all these developed neutralizing antibodies. Although viremias were detectable in all but one chicken, the magnitude (mean peak viremia <10,000 PFU/mL) was deemed insufficient to infect vector mosquitoes. WNV-NY99 was detected in cloacal and/or throat swabs from 13 of these chickens, and direct transmission of WNV-NY99 between chickens occurred once (in 16 trials), from a needle-inoculated bird. Nine chickens that ingested WNV-NY99 failed to become infected. The domestic chickens in this study were susceptible to WN virus infection, developed detectable antibodies, survived infection, and with one exception failed to infect cage mates. These are all considered positive attributes of a sentinel species for WN virus surveillance programs.


Li, W; Brinton, M A. The 3' stem loop of the West Nile virus genomic RNA can suppress translation of chimeric mRNAs. Virology. 2001 Aug 15; 287(1): 49-61. ISSN:  0042-6822.

NAL Call No.: 448.8 V81

Descriptors:   viral genetic effects, RNA translation inhibition, nucleic acid conformation, Northern blotting, ELISA,  hamsters. Abstract: Cis-acting elements that regulate translation have been identified in the 3' noncoding regions (NCRs) of cellular and viral mRNAs. As one means of analyzing the effect on translation of the conserved 3' terminal RNA structure of the West Nile virus (WNV) genome, the translation efficiencies of chimeric mRNAs composed of a CAT reporter gene flanked by viral or nonviral 5' and 3' terminal sequences were compared. In vitro, the WNV 3'(+) stem loop (SL) RNA reduced the translation efficiencies of chimeric mRNAs with either viral or nonviral 5' NCRs, suggesting that a specific 3'-5' RNA-RNA interaction was not involved. In contrast, the 3' terminal sequence of a togavirus, rubella virus, enhanced translation efficiency. The WNV 3'(+)SL reduced translation efficiency both in cis and in trans and of both capped and uncapped chimeric mRNAs. We have previously reported that three cellular proteins bind specifically to the WNV 3'(+)SL RNA. Competition between the WNV 3'(+)SL and the 5' terminus of the chimeric mRNAs for proteins involved in translation initiation could explain the translation inhibition observed. Copyright 2001 Academic Press.


Malkinson, M; Weisman, Y; Pokamonski, S; King, R; Deubel, V. Intercontinental transmission of West Nile virus by migrating white storks. Emerging Infectious Diseases. 2001; 7(3 Suppl): 540. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   disease transmission, bird physiology, West Nile virus dispersion patterns, greographic movement of disease, Europe, Israel, migration birds as disease reservoirs, storks. 


Marfin, A A; Petersen, L R; Eidson, M; Miller, J; Hadler, J; Farello, C; Werner, B; Campbell, G L; Layton, M; Smith, P; Bresnitz, E; Cartter, M; Scaletta, J; Obiri, G; Bunning, M; Craven, R C; Roehrig, J T; Julian, K G; Hinten, S R; Gubler, D J. Widespread West Nile virus activity, eastern United States, 2000. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 730-5. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   ArboNET, cooperative inter-state surveillance system, data collection of disease spread in the U.S., animal disease as predictors of human risks of disease, disease outbreaks, birds, horses, Culicidae mosquitoes, songbird disease, epidemiology.

Abstract: In 1999, the U.S. West Nile (WN) virus epidemic was preceded by widespread reports of avian deaths. In 2000, ArboNET, a cooperative WN virus surveillance system, was implemented to monitor the sentinel epizootic that precedes human infection. This report summarizes 2000 surveillance data, documents widespread virus activity in 2000, and demonstrates the utility of monitoring virus activity in animals to identify human risk for infection.


McLean, R G; Ubico, S R; Docherty, D E; Hansen, W R; Sileo, L; McNamara, T S. West Nile virus transmission and ecology in birds. Annals of the New York Academy of Sciences. 2001 Dec; 951: 54-7. ISSN: 0077-8923.

NAL Call No.: 500 N484

Descriptors:   captive crows, experimental infection, 1999 NY strain of virus, viremic levels, controls   infected by possible oral transmission, direct transmission.

Abstract: The ecology of the strain of West Nile virus (WNV) introduced into the United States in 1999 has similarities to the native flavivirus, St. Louis encephalitis (SLE) virus, but has unique features not observed with SLE virus or with WNV in the old world. The primary route of transmission for most of the arboviruses in North America is by mosquito, and infected native birds usually do not suffer morbidity or mortality. An exception to this pattern is eastern equine encephalitis virus, which has an alternate direct route of transmission among nonnative birds, and some mortality of native bird species occurs. The strain of WNV circulating in the northeastern United States is unique in that it causes significant mortality in exotic and native bird species, especially in the American crow (Corvus brachyrhynchos). Because of the lack of information on the susceptibility and pathogenesis of WNV for this species, experimental studies were conducted at the USGS National Wildlife Health Center. In two separate studies, crows were inoculated with a 1999 New York strain of WNV, and all experimentally infected crows died. In one of the studies, control crows in regular contact with experimentally inoculated crows in the same room but not inoculated with WNV succumbed to infection. The direct transmission between crows was most likely by the oral route. Inoculated crows were viremic before death, and high titers of virus were isolated from a variety of tissues. The significance of the experimental direct transmission among captive crows is unknown.


Mishra, A C; Mourya, D T. Transovarial transmission of West Nile virus in Culex vishnui mosquito. Indian Journal of Medical Research. 2001 Dec; 114: 212-4. ISSN:  0971-5916.

Descriptors:   Culex vishnui mosquito, biology of transovarial transmission of West Nile virus, 1st and 2nd gonotropic cycles, role of mosquito in maintaining population of West Nile virus,

Abstract: The phenomenon of transovarial transmission (TOT) of West Nile (WN) virus in Culex vishnui was studied. The virus was detected in the progeny of both first and second gonotropic cycles (G1 and G2). About 5.56 per cent pools of F1 progeny from the parent females infected by the oral route were found positive for WN virus. This is the first report of TOT of WN virus in this species of mosquito. The occurrence of this phenomenon is of considerable importance in view of complex natural cycle of the virus and the high density of this vector species in nature. The results suggest that this mosquito may be involved in the maintenance of this virus in nature.


Monath, TP. Prospects for development of a vaccine against the West Nile virus. Annals of the New York Academy of Sciences. 2001 Dec; 951: 1-12. ISSN: 0077-8923.

NAL Call No.: 500 N484

Descriptors:   feasibility of vaccine development, humans, horses, formalin inactivated virus-based vaccine, comparison with live attenuated recombinant vaccine, viron, West Nile virus protein coat.

Abstract: Vaccination provides the ultimate measure for personal protection against West Nile disease. The development of a West Nile vaccine for humans is justified by the uncertainty surrounding the size and frequency of future epidemics. At least two companies (Acambis Inc. and Baxter/immuno) have initiated research and development on human vaccines. West Nile encephalitis has also emerged as a significant problem for the equine industry. One major veterinary vaccine manufacturer (Ft. Dodge) is developing formalin-inactivated and naked DNA vaccines. The advantages and disadvantages of formalin-inactivated whole virion vaccines, Japanese encephalitis vaccine for cross-protection, naked DNA, and live attenuated vaccines are described. A novel technology platform for live, attenuated recombinant vaccines (ChimeriVax) represents a promising approach for rapid development of a West Nile vaccine. This technology uses yellow fever 17D as a live vector for envelope genes of the West Nile virus. Infectious clone technology is used to replace the genes encoding the prM and E structural proteins of yellow fever 17D vaccine virus with the corresponding genes of West Nile virus. The resulting virion has the protein coat of West Nile, containing all antigenic determinants for neutralization and one or more epitopes for cytotoxic T lymphocytes. The genes encoding the nucleocapsid protein, nonstructural proteins, and untranslated terminal regions responsible for replication remain those of the original yellow fever 17D virus. The chimeric virus replicates in the host like yellow fever 17D but immunizes specifically against West Nile virus.


Morrey J D; Smee D F; Sidwell R W. In vitro evaluation of compounds against West Nile virus. Antiviral Research. April, 2001; 50 (1): A70. ISSN: 0166-3542. Fourteenth International Conference on Antiviral Research, Seattle, Washington, USA, April 08-12, 2001.

NAL Call No.: QR355.A5

Descriptors: New York isolate, Vero cell line, anti-viral drugs, 2-thio-6-azauridine enzyme inhibitor drug,  6-azauridine enzyme inhibitor drug, GTP synthesis, IMP dehydrogenase, OMP decarboxylase, TTP synthesis, UTP synthesis, adenosine analogs, cyclopentenylcytosine [CPE-C] enzyme inhibitor drug, pyrazofurin enzyme inhibitor drug, selenazofurin enzyme inhibitor drug.


Musa Hindiyeh; Shulman LM; Mendelson E; Weiss L; Grossman Z; Bin H. Isolation and characterization of West Nile virus from the blood of viremic patients during the 2000 outbreak in Israel. Emerging Infectious Diseases. 2001, 7: 4, 748-750; 17 ref. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   viral strain lineages, 1999 New York isolate, Russian isolates, Israel isolate.


Nasci, R S; Savage, H M; White, D J; Miller, J R; Cropp, B C; Godsey, M S; Kerst, A J; Bennett, P; Gottfried, K; Lanciotti, R S. West Nile virus in overwintering Culex mosquitoes, New York City, 2000. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 742-4. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   overwintering adult mosquitoes tested for West Nile virus, RT  PCR, Culex pipiens, vector mosquitoes in northeastern U.S, Aedes cytology, Vero cells, seasonal effects. 

Abstract: After the 1999 West Nile (WN) encephalitis outbreak in New York, 2,300 overwintering adult mosquitoes were tested for WN virus by cell culture and reverse transcriptase-polymerase chain reaction. WN viral RNA and live virus were found in pools of Culex mosquitoes. Persistence in overwintering Cx. pipiens may be important in the maintenance of WN virus in the northeastern United States.


Nasci, R S; White, D J; Stirling, H; Oliver, J A; Daniels, T J; Falco, R C; Campbell, S; Crans, W J; Savage, H M; Lanciotti, R S; Moore, C G; Godsey, M S; Gottfried, K L; Mitchell, C J. West Nile virus isolates from mosquitoes in New York and New Jersey, 1999. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 626-30. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   mosquitoes survival, 24 mosquitoes species, 15 isolates of West Nile virus, main reservoir is Culex pipiens, other Culex sp, Aedes, Anopheles, Cereopithecus aethiops, viral genetics.

Abstract: An outbreak of encephalitis due to West Nile (WN) virus occurred in New York City and the surrounding areas during 1999. Mosquitoes were collected as part of a comprehensive surveillance program implemented to monitor the outbreak. More than 32,000 mosquitoes representing 24 species were tested, and 15 WN virus isolates were obtained. Molecular techniques were used to identify the species represented in the WN virus-positive mosquito pools. Most isolates were from pools containing Culex pipiens mosquitoes, but several pools contained two or more Culex species.


Ng, M L; Tan, S H; Chu, J J. Transport and budding at two distinct sites of visible nucleocapsids of West Nile (Sarafend) virus. Journal of Medical Virology. 2001 Dec; 65(4): 758-64. ISSN: 0146-6615.

Descriptors:   cryo-immunoelectron microscopy, capsid proteins, neocapsid particles, nucleocapsid physiology, replication cycle, viral envelope protein analysis, virus ultrastructure, Vero cells.

Abstract: It has been difficult to detect and visualize the physical nucleocapsid particles during the replication process of the flaviviruses. The use of cryo-immunoelectron microscopy has clearly revealed the capsid proteins and nucleocapsid particles of West Nile (Sarafend) virus (a flavivirus) for the first time. Physical nucleocapsid particles accumulated in large numbers from 8 hr postinfection. Double immunolabeling of the envelope and capsid proteins showed a close association of these structural proteins for most of the replication cycle. By 10 hr postinfection, budding of nucelocapsids from the plasma membrane was very obvious. Although maturation at the plasma membrane was the dominant mode, during late infection, intracellular maturation into large vacuoles was also observed.


Nolen, R S. Nation's zoos and aquariums help track West Nile virus. JAMA -- Journal of the American Veterinary Medical Association. 2001 Nov 15; 219(10): 1327, 1330. ISSN:  0003-1488.

NAL Call No.: 41.8 Am3

Descriptors:   wild and captive animals susceptibility to West Nile virus, horses, songbirds, monitoring of disease spread, zoological parks and aquarium animal collections.


Panella, N A; Kerst, A J; Lanciotti, R S; Bryant, P; Wolf, B; Komar, N. Comparative West Nile virus detection in organs of naturally infected American Crows (Corvus brachyrhynchos). Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 754-5. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   West Nile virus disease in birds, deaths of American crows, levels of virus in various organ tissues, detection in brain tissue.

Abstract: Widespread deaths of American Crows (Corvus brachyrhynchos)were associated with the 1999 outbreak of West Nile (WN) virus in the New York City region. We compared six organs from 20 crow carcasses as targets for WN virus detection. Half the carcasses had at least one positive test result for WN virus infection. The brain was the most sensitive test organ; it was the only positive organ for three of the positive crows. The sensitivity of crow organs as targets for WN virus detection makes crow death useful for WN virus surveillance.


Parquet, M C; Kumatori, A; Hasebe, F; Morita, K; Igarashi, A. West Nile virus-induced bax-dependent apoptosis.

FEBS Letters. 2001 Jun 29; 500(1-2): 17-24. ISSN: 0014-5793.

NAL Call No.: QD415.F4

Descriptors:   cell lines, K562 and Neuro-2a cells, cell shrinkage, chromatin concdensation, subdiploid DNA content, DAN destruction, cell wall membrane changes, viral replication.

Abstract: The mechanism of cell death induced by West Nile virus (WNV), a causative agent of human febrile syndrome and encephalitis, was investigated. WNV-infected K562 and Neuro-2a cells manifested the typical features of apoptosis, including cell shrinkage, chromatin condensation and subdiploid DNA content by flow cytometry. DNA fragmentation into nucleosomal size and changes in outer cell membrane phospholipid composition were also observed in K562 cells. UV-inactivated virus failed to induce the above-mentioned characteristics, suggesting that viral replication may be required for the induction of apoptosis by WNV. Additionally, signals involved in WNV-induced apoptosis are associated with the up-regulation of bax gene expression.


Petersen, L R; Roehrig, J T. West Nile virus: a reemerging global pathogen. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 611-4. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   zoonotic virus, emerging disease epidemiology, genetics, virus strains, isolation and purification, viral metabolism, review article, virulence mutations, Culex mosquitoes, insect vectors, world-wide pathogen movements.


Petersen LR; Roehrig JT; Petersen LR (ed.); Roehrig JT. West Nile virus. Emerging Infectious Diseases. 2001, 7: 4, 611-764. ISSN:  1080-6040. Special issue focusing on West Nile virus with 30 papers on a variety of topics.

NAL Call No.: RA648.5 E46

Descriptors:   biology, ecology and epidemiology of West Nile virus, surveillance systems, disease outbreaks, genetics, Culicidae mosquito vectors, humans, horses, birds, detection.


Sardelis, M.R.; M. Turell. Ochlerotatus j. japonicus in Frederick County, Maryland: discovery, distribution, and vector competence for West Nile virus. Journal of the American Mosquito Control Association. June 2001. v. 17 (2) p. 137-141. ISSN: 8756-971X.

NAL call no:  QL536.J686

Descriptors: Culicidae, Aedes albopictus, surveys, oviposition traps, mosquitoes, geographical distribution, new geographic records, disease vectors, vector competence, West Nile virus, disseminated infections, disease transmission, Maryland.


Sardelis, M R; Turell, M J; Dohm, D J; O'Guinn, M L. Vector competence of selected North American Culex and Coquillettidia mosquitoes for West Nile virus. Emerging Infectious Diseases. 2001 Nov-Dec; 7(6): 1018-22. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   viral transmission efficiency, vector potential of various mosquito species, Culex restuans, Culex salinarius, Culex quinquefasciatus, Culex nigripalpus, Coquillettidia perturbans, chickens, North America.

Abstract: To control West Nile virus (WNV), it is necessary to know which mosquitoes are able to transmit this virus. Therefore, we evaluated the WNV vector potential of several North American mosquito species. Culex restuans and Cx. salinarius, two species from which WNV was isolated in New York in 2000, were efficient laboratory vectors. Cx. quinquefasciatus and Cx. nigripalpus from Florida were competent but only moderately efficient vectors. Coquillettidia perturbans was an inefficient laboratory vector. As WNV extends its range, exposure of additional mosquito species may alter its epidemiology.


Shi , P Y; Kauffman, E B; Ren, P; Felton, A; Tai, J H; Dupuis, A P 2nd; Jones, S A; Ngo, K A; Nicholas, D C; Maffei, J; Ebel, G D; Bernard, K A; Kramer, L D. High-throughput detection of West Nile virus RNA. Journal of Clinical Microbiology. 2001 Apr; 39(4): 1264-71. ISSN: 0095-1137.

NAL Call No.: QR46.J6

Descriptors: surveillance protocols, automated RNA extraction, amplification and detection, robotic system, hight sensitivity method. RT PCR, virus isolation and purification, time factors,  large scale viral RNA surveillance.

Abstract: The recent outbreaks of West Nile virus (WNV) in the northeastern United States and other regions of the world have made it essential to develop an efficient protocol for surveillance of WNV. In the present report, we describe a high-throughput procedure that combines automated RNA extraction, amplification, and detection of WNV RNA. The procedure analyzed 96 samples in approximately 4.5 h. A robotic system, the ABI Prism 6700 Automated Nucleic Acid workstation, extracted RNA and set up reactions for real-time reverse transcription (RT)-PCR in a 96-well format. The robot extracted RNA with a recovery as efficient as that of a commercial RNA extraction kit. A real-time RT-PCR assay was used to detect and quantitate WNV RNA. Using in vitro transcribed RNA, we estimated the detection limit of the real-time RT-PCR to be approximately 40 copies of RNA. A standard RT-PCR assay was optimized to a sensitivity similar to that of the real-time RT-PCR. The standard assay can be reliably used to test a small number of samples or to confirm previous test results. Using internal primers in a nested RT-PCR, we increased the sensitivity by approximately 10-fold compared to that of the standard RT-PCR. The results of the study demonstrated for the first time that the use of an automated system for the purpose of large-scale viral RNA surveillance dramatically increased the speed and efficiency of sample throughput for diagnosis.


Sibbald, B. Quebec clears way for use of aerial pesticides to combat West Nile virus. Canadian Medical Association Journal . 2001 Aug 21; 165(4): 463. ISSN: 0820-3946.

NAL Call No.: R11 C3

Descriptors:   Canada, disease prevention, arial spraying for mosquito control, malathion, administration and dosages, adverse effects, birds, Quebec.


Snook, C.S.; S. Hyman; F. Del Piero; J. Palmer; E. Ostlund; B. Barr; A. Desrochers; L. Reilly. West Nile virus encephalomyelitis in eight horses. Journal of the American Veterinary Medical Association. May 15, 2001. v. 218 (10) p. 1576-1579. ISSN: 0003-1488.

NAL call no:  41.8 Am3

Descriptors: horses, West Nile virus, West Nile fever, encephalitis, symptoms, clinical aspects, diagnosis, treatment, prognosis, case reports, New York, New Jersey.


SoRelle, R. West Nile virus spreading. Circulation. 2001 Aug 14; 104(7): E9011-3 ISSN: 1524-4539.

Descriptors:  epidemiology, transmission, virus isolation and purification, disease spread, implication for prevention and control.


Swayne, D E; Beck, J R; Smith, C S; Shieh, W J; Zaki, S R. Fatal encephalitis and myocarditis in young domestic geese (Anser anser domesticus) caused by West Nile virus. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 751-3. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:  experimental infection, young geese, effects of disease on geese, clinical signs, possible reservoir for the virus, mosquito vector.

Abstract: During 1999 and 2000, a disease outbreak of West Nile (WN) virus occurred in humans, horses, and wild and zoological birds in the northeastern USA. In our experiments, WN virus infection of young domestic geese (Anser anser domesticus) caused depression, weight loss, torticollis, opisthotonus, and death with accompanying encephalitis and myocarditis. Based on this experimental study and a field outbreak in Israel, WN virus is a disease threat to young goslings and viremia levels are potentially sufficient to infect mosquitoes and transmit WN virus to other animal species.


Trock, S C; Meade, B J; Glaser, A L; Ostlund, E N; Lanciotti, R S; Cropp, B C; Kulasekera, V; Kramer, L D; Komar, N. West Nile virus outbreak among horses in New York State, 1999 and 2000. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 745-7. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   humans/horses disease correlations, epidemiology, Culex mosquitoes species as disease vectors, physiopathology, Aedes, disease pathology, viral genetics, immunology, RT PCR, New York State.

Abstract: West Nile (WN) virus was identifiedin the Western Hemisphere in 1999. Along with human encephalitis cases, 20 equine cases of WN virus were detected in 1999 and 23 equine cases in 2000 in New York. During both years, the equine cases occurred after human cases in New York had been identified.


Turell, M J; Sardelis, M R; Dohm, D J; O'Guinn, M L. Potential North American vectors of West Nile virus. Annals of the New York Academy of Sciences. 2001 Dec; 951: 317-24.ISSN: 0077-8923.

NAL Call No.: 500 N484        

Descriptors:   vector efficiency testing, Culex pipiens, Culex nigripalpus, Culex quinquefasciatus, Culex salinarius, Aedes albopictus, Aedes vexans, Ochlerotatus japonicus, Ochlerotatus sollicitans, Ochlerotatus taeniorhynchus, and Ochlerotatus triseriatus, mosquito from inoculated chicks, environmental factors, populations, lifespan, mosquito feeding habits. 

Abstract: The outbreak of disease in the New York area in 1999 due to West Nile (WN) virus was the first evidence of the occurrence of this virus in the Americas. To determine potential vectors, more than 15 mosquito species (including Culex pipiens, Cx. nigripalpus, Cx. quinquefasciatus, Cx. salinarius, Aedes albopictus, Ae. vexans, Ochlerotatus japonicus, Oc. sollicitans, Oc. taeniorhynchus, and Oc. triseriatus) from the eastern United States were evaluated for their ability to serve as vectors for the virus isolated from birds collected during the 1999 outbreak in New York. Mosquitoes were allowed to feed on one- to four-day old chickens that had been inoculated with WN virus 1-3 days previously. The mosquitoes were incubated for 12-15 days at 26 degrees C and then allowed to refeed on susceptible chickens and assayed to determine transmission and infection rates. Several container-breeding species (e.g., Ae. albopictus, Oc. atropalpus, and Oc. japonicus) were highly efficient laboratory vectors of WN virus. The Culex species were intermediate in their susceptibility. However, if a disseminated infection developed, all species were able to transmit WN virus by bite. Factors such as population density, feeding preference, longevity, and season of activity also need to be considered in determining the role these species could play in the transmission of WN virus.


Turell, M.J.; M. O'Guinn; D. Dohm; J. Jones. Vector competence of North American mosquitoes (Diptera: Culicidae) for West Nile virus. Journal of Medical Entomology. Mar 2001. v. 38 (2) p. 130-134. ISSN: 0022-2585.

NAL call no:  421 J828

Descriptors: Aedes aegypti, Aedes albopictus, Aedes atropalpus, Aedes japonicus, Aedes sollicitans, Aedes taeniorhynchus, Aedes vexans, Culex pipiens, West Nile virus, susceptibility, disseminated infections, disease vectors, vector competence, disease transmission, New York City, Virginia, North America.

Abstract: We evaluated the potential for several North American mosquito species to transmit the newly introduced West Nile (WN) virus. Mosquitoes collected in the New York City metropolitan area during the recent WN virus outbreak, at the Assateague Island Wildlife Refuge, VA, or from established colonies were allowed to feed on chickens infected with WN virus isolated from a crow that died during the 1999 outbreak. These mosquitoes were tested approximately equal to 2 wk later to determine infection, dissemination, and transmission rates. Aedes albopictus (Skuse), Aedes atropalpus (Coquillett), and Aedes japonicus (Theobald) were highly susceptible to infection, and nearly all individuals with a disseminated infection transmitted virus by bite. Culex pipiens L. and Aedes sollicitans (Walker) were moderately susceptible. In contrast, Aedes vexans (Meigen), Aedes aegypti (L.), and Aedes taeniorhynchus (Wiedemann) were relatively refractory to infection, but individual mosquitoes inoculated with WN virus did transmit virus by bite. Infected female Cx. pipiens transmitted WN virus to one of 1,618 F1 progeny, indicating the potential for vertical transmission of this virus. In addition to laboratory vector competence, host-feeding preferences, relative abundance, and season of activity also determine the role that these species could play in transmitting WN virus.


Tyler, KL. West Nile virus encephalitis in America. New England Journal of Medicine. 2001 Jun 14; 344(24): 1858-9. ISSN: 0028-4793.

NAL Call No.: 448.8 N442

Descriptors: disease outbreaks, New York City, epidemiology, virus isolation, PCR, surveillance, diagnosis, transmission. 


Wang, T; Anderson, J F; Magnarelli, L A; Bushmich, S; Wong, S; Koski, R A; Fikrig, E. West Nile virus envelope protein: role in diagnosis and immunity. Annals of the New York Academy of Sciences. 2001 Dec; 951: 325-7. ISSN: 0077-8923.

NAL Call No.: 500 N484

Descriptors:   antibodies, viral envelope proteins, diagnosis, immunology,  inbred C3H mice, recombinant proteins immunology, level of protection, passive immunization, rabbits, mice, diagnostic aid.  

Abstract: The role of antibodies to the West Nile virus envelope (E) protein in serodiagnosis and protection was examined. The E protein was expressed and purified in recombinant form. Antibodies to the E protein were detected in patients with West Nile virus infection. Passive immunization with rabbit anti-E protein sera also partially protected mice from challenge with West Nile virus. The humoral response to the West Nile virus E protein is therefore useful as an aid in the diagnosis and may also play a role in immunity to infection.


Wang, T; Anderson, J F; Magnarelli, L A; Wong, S J; Koski, R A; Fikrig, E. Immunization of mice against West Nile virus with recombinant envelope protein. Journal of Immunology. 2001 Nov 1; 167(9): 5273-7. ISSN: 0022-1767.

Descriptors: recombinant envelope protein, C3H/HeN mice, immunized with E protein, antibody development, level of protection, possible immunization potential for a vaccine.

Abstract: West Nile (WN) virus is a mosquito borne flavivirus that emerged in the United States in 1999 and can cause fatal encephalitis. Envelope (E) protein cDNA from a WN virus isolate recovered from Culex pipiens in Connecticut was expressed in Escherichia coli. The recombinant E protein was purified and used as Ag in immunoblot assays and immunization experiments. Patients with WN virus infection had Abs that recognized the recombinant E protein. C3H/HeN mice immunized with E protein developed E protein Abs and were protected from infection with WN virus. Passive administration of E protein antisera was also sufficient to afford immunity. E protein is a candidate vaccine to prevent WN virus infection.


White, DJ. Vector surveillance for West Nile virus. Annals of the New York Academy of Sciences. 2001 Dec; 951: 74-83. ISSN: 0077-8923.

NAL Call No.: 500 N484

Descriptors:   mosquito and West Nile virus surveillance programs, response plan, vector population data, movement of 8 mosquito species, control efficacy, public health concerns, epidemiology, New York State, Culicidae, sentinel surveillance, virus genetics. 

Abstract: West Nile virus (WNV) was detected in the metropolitan New York City (NYC) area during the summer and fall of 1999. Sixty-two human cases, including seven fatalities, were documented. The New York State Department of Health (NYSDOH) initiated and implemented a statewide mosquito and WNV surveillance system. We developed a WNV response plan designed to provide local health departments (LHD) a standardized means to begin to assess basic mosquito population data and to detect WNV circulation in mosquito populations. During the 2000 arbovirus surveillance season, local health agencies collected 317,676 mosquitoes and submitted 9,952 pools for virus testing. NYSDOH polymerase chain reaction (PCR) testing detected 363 WNV-positive pools. Eight species of mosquitoes were found to be infected. Of the 26 counties conducting mosquito surveillance, WNV-positive mosquitoes were detected only in NYC, on Long Island, and in four counties in the lower Hudson River valley region. LHD larval surveillance provided initial or enhanced mosquito habitat location and characterization and mosquito species documentation. Adult mosquito surveillance provided LHD information on species' presence, density, seasonal fluctuations, virus infection, minimum infection ratios (MIR) and indirect data on mosquito control efficacy after larval or adult control interventions. Collective surveillance activities conducted during 1999 and 2000 suggest that WNV has dispersed throughout the state and may affect local health jurisdictions within NYS, adjacent states, and Canada in future years. Vector surveillance will remain a critical component of LHD programs addressing public health concerns related to WNV.


White, D J; Kramer, L D; Backenson, P B; Lukacik, G; Johnson, G; Oliver, J A; Howard, J J; Means, R G; Eidson, M; Gotham, I; Kulasekera, V; Campbell, S. Mosquito surveillance and polymerase chain reaction detection of West Nile virus, New York State. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 643-9. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:   state-wide mosquito and virus surveillance system, 8 species as disease vectors, exposure risks, PCR testing to confirm the virus, human exposure risks, New York State.

Abstract: West Nile (WN) virus was detected in the metropolitan New York City (NYC) area during the summer and fall of 1999. Sixty-two human cases, 7 fatal, were documented. The New York State Department of Health initiated a departmental effort to implement a statewide mosquito and virus surveillance system. During the 2000 arbovirus surveillance season, we collected 317,676 mosquitoes, submitted 9,952 pools for virus testing, and detected 363 WN virus-positive pools by polymerase chain reaction (PCR). Eight species of mosquitoes were found infected. Our mosquito surveillance system complemented other surveillance systems in the state to identify relative risk for human exposure to WN virus. PCR WN virus-positive mosquitoes were detected in NYC and six counties in the lower Hudson River Valley and metropolitan NYC area. Collective surveillance activities suggest that WN virus can disperse throughout the state and may impact local health jurisdictions in the state in future years.


Xiao, S Y; Guzman, H; Zhang, H; Travassos da Rosa, A P; Tesh, R B. West Nile virus infection in the golden hamster (Mesocricetus auratus): a model for West Nile encephalitis. Emerging Infectious Diseases. 2001 Jul-Aug; 7(4): 714-21. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors: animal disease model, golden hamsters, New York isolate, levels of viremia, antibody responses, symptoms of disease, viral persistence pathogenesis.   

Abstract: This report describes a new hamster model for West Nile (WN) virus encephalitis. Following intraperitoneal inoculation of a New York isolate of WN virus, hamsters had moderate viremia of 5 to 6 days in duration, followed by the development of humoral antibodies. Encephalitic symptoms began 6 days after infection; about half the animals died between the seventh and 14th days. The appearance of viral antigen in the brain and neuronal degeneration also began on the sixth day. WN virus was cultured from the brains of convalescent hamsters up to 53 days after initial infection, suggesting that persistent virus infection occurs. Hamsters offer an inexpensive model for studying the pathogenesis and treatment of WN virus encephalitis.


Yang, J S; Kim, J J; Hwang, D; Choo, A Y; Dang, K; Maguire,-H; Kudchodkar, S; Ramanathan, M P; Weiner, D B. Induction of potent Th1-type immune responses from a novel DNA vaccine for West Nile virus New York isolate (WNV-NY1999). Journal of Infectious Diseases. 2001 Oct 1; 184(7): 809-16. ISSN:  0022-1899.

Descriptors:   DNA vaccine development, encoded West Nile virus capsid protein, mouse model, muscle injections, humoral/cellular responses, lumphocyte responses, T-cells, macrophages, potential use as vaccine evaluated.  

Abstract: West Nile virus (WNV) is a vectorborne pathogen that induces brain inflammation and death. Recently, confirmed cases of infection and deaths have occurred in the United States Mid-Atlantic region. In this study, a DNA vaccine encoding the WNV capsid protein was constructed, and the in vivo immune responses generated were investigated in DNA vaccine-immunized mice. Antigen-specific humoral and cellular immune responses were observed, including a potent induction of antigen-specific Th1 and cytotoxic T lymphocyte responses. Strong induction of Th1-type immune responses included high levels of antigen-specific elaboration of the Th1-type cytokines interferon-gamma and interleukin-2 and beta-chemokines RANTES (regulated upon activation, normal T cell-expressed and secreted) and macrophage inflammatory protein-1beta. Dramatic infiltration of CD4 and CD8 T cells and macrophages also was observed at the muscle injection site. These results support the potential utility of this method as a tool for developing immunization strategies for WNV and other emerging pathogens.


Zeller, HG; Murgue, B. Role des oiseaux migrateurs dans l'epidemiologie du virus West Nile. [The role of migrating birds in the West Nile virus epidemiology.] 10e Colloque sur le controle epidemiologique des maladies infectieuses (CEMI): Epidemiologie, surveillance et prevention des zoonoses, 4 mai 2001, Institut Pasteur, Paris, France. Medecine-et-Maladies-Infectieuses. 2001, 31: Supplement2, 168s-174s; 27 ref. ISSN: 0399-077X. In French with an English summary.

Descriptors:   West Nile virus outbreaks, transmission cycle, epidemiology, movement of disease via migrating birds, factors supporting outbreaks, disease vectors, humans, horses, Culex mosquitoes as disease vectors, susceptible birds, Europe, Africa.


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February 6, 2003