Anonymous. From the Centers for Disease Control and Prevention. Surveillance for West Nile virus in overwintering mosquitoes--New York, 2000. JAMA -- The Journal of the American Medical Association. 2000 May 10; 283(18): 2380-1. ISSN: 0098-7484.

NAL Call No.: 448.9 Am37

Descriptors:  West Nile virus disease vector mosquitoes, levels of virus, overwintering mosquitoes, epidemiology, New York State, Culicidae, prevention and control.   


Anonymous. Guidelines for surveillance, prevention, and control of West Nile virus infection--United States. MMWR Morbidity and Mortality Weekly Report. 2000 Jan 21; 49(2): 25-8. ISSN: 0149-2195.

NAL Call No.: RA407.3 M56

Descriptors:  guidance for surveillance programs, disease prevention and control, CDC and USDA sponsored meeting report, guidelines summary, laboratory techniques and procedures, virus isolation and purification.   

Abstract: The introduction of West Nile (WN) virus in the northeastern United States during the summer and fall of 1999 raised the issue of preparedness of public health agencies to handle sporadic and outbreak-associated vector-borne diseases. In many local and state health departments, vector-borne disease capacity has diminished. Because it is unknown whether the virus can persist over the winter, whether it has already or will spread to new geographic locations, and the public health and animal health implications of this introduction, it is important to establish proactive laboratory-based surveillance and prevention and control programs to limit the impact of the virus in the United States. On November 8 and 9, 1999, CDC and the U.S. Department of Agriculture (USDA) cosponsored a meeting of experts representing a wide range of disciplines to review the outbreak and to provide input and guidance on the programs that should be developed to monitor WN virus activity and to prevent future outbreaks of disease. This report summarizes the guidelines established during this meeting.


Anonymous. Update: West Nile virus activity--Eastern United States, 2000. MMWR Morbidity and Mortality Weekly Report. 2000 Nov 24; 49(46): 1044-7. ISSN: 0149-2195.

NAL Call No.: RA407.3 M56

Descriptors:   disease epidemiology in wild birds, horses, and humans, sentinel chicken flocks, Culicidae mosquitoes virology, virus isolation and purification, levels of disease in Mid-Atlantic states.

Abstract:  Data reported to CDC through the West Nile Virus (WNV) Surveillance System have shown an increase in the geographic range of WNV activity in 2000 compared with 1999, the first year that WNV was reported in the Western Hemisphere. In response to this occurrence of WNV, 17 states along the Atlantic and Gulf coasts, New York City, and the District of Columbia conducted WNV surveillance, which included monitoring mosquitoes, sentinel chicken flocks, wild birds, and potentially susceptible mammals (e.g., horses and humans). In 1999, WNV was detected in four states (Connecticut, Maryland, New Jersey, and New York) . In 2000, epizootic activity in birds and/or mosquitoes was reported from 12 states (Connecticut, Delaware, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, Vermont, and Virginia) and the District of Columbia. Of the 13 jurisdictions, seven also reported severe neurologic WNV infections in humans, horses, and/or other mammal species. This report presents surveillance data reported to CDC from January 1 through November 15.


Anonymous. Update: West Nile virus activity--Northeastern United States, January-August 7, 2000. MMWR Morbidity and Mortality Weekly Report. 2000 Aug 11; 49(31): 714-8. ISSN: 0149-2195.

NAL Call No.: RA407.3 M56

Descriptors:  bird diseases, epidemiology, Culicidae virology, insect vectors,  virus isolation and purification, mosquito monitoring, sentinel chicken flocks, wild birds, surveillance system, Eastern U.S.

Abstract:  Surveillance programs initiated in response to the 1999 West Nile virus (WNV) outbreak have detected increased transmission in the northeastern United States (1). Seventeen states along the Atlantic and gulf coasts, New York City (NYC), and Washington, D.C., have conducted WNV surveillance and are reporting to CDC (1). Surveillance for WNV infection includes monitoring of mosquitoes, sentinel chicken flocks, wild birds, and potentially susceptible mammals (e.g., horses and humans) (2). This report summarizes findings of this surveillance system through August 7, 2000.


Anonymous. West Nile virus activity--New York and New Jersey, 2000. MMWR Morbidity and Mortality Weekly Report. 2000 Jul 21; 49(28): 640-2. ISSN: 0149-2195.

NAL Call No.: RA407.3 M56

Descriptors:   bird diseases, epidemiology, diagnosis, Culicidae, virus isolation and purification, New York, New Jersey. 

Abstract:  In late August 1999, an outbreak of encephalitis caused by West Nile virus (WNV) was detected in New York City and subsequently identified in neighboring counties (1). In response, an extensive mosquito-control and risk-reduction campaign was initiated, including aerial and ground applications of mosquito adulticides throughout the affected areas. No human WNV infections were found in New York City with an onset date after the campaign was completed. Cases continued to occur among humans in surrounding counties that did not undertake mosquito-control efforts until later, suggesting that the campaign may have reduced human risk. In May 2000, CDC issued guidelines to direct national surveillance, prevention, and control efforts (2) and provided funds to support these efforts in 19 state and local health departments where WNV transmission had occurred or where transmission would probably occur based on known bird migration patterns. This report presents the findings of surveillance activities.


Anonymous. West Nile virus in Rhode Island. Journal of the American Veterinary Medical Association. 2000 Sep 15; 217(6): 812. ISSN: 0003-1488.

NAL Call No.: 41.8 Am3

Descriptors:   virology, prevention and control, isolation and purification, songbirds virology, Rhode Island, epidemiology, mosquito control.


Anonymous. West Nile virus in the Americas. Epidemiological Bulletin. 2000 Dec; 21(4): 9-11. ISSN: 0256-1859.

Descriptors:  epidemiology, Culicidae mosquito species, insect vectors of disease, transmission of virus, virus physiology, Mid-Atlantic states, U.S.


Anonymous. Infection a virus West Nile chez des chevaux dans le sud de la France, Septembre 2000. [West Nile virus infection in horses in the south of France, September 2000.] Bulletin Epidemiologique Hebdomadaire. 2000, No. 39, 173. In French.

Descriptors: horses, clinical signs of West Nile virus, control measures to eliminate Culex modestus as disease vector, serological testing, southern France.


Bertrand, T; Bandy, U. West Nile virus surveillance and prevention. Medicine and Health, Rhode Island. 2000 May; 83(5): 160-1. ISSN:  1086-5462.

Descriptors:  epidemiology, disease prevention and control, disease incidence, disease risk factors, Rhode Island. 


Calisher, C H. West Nile virus in the New World: appearance, persistence, and adaptation to a new econiche--an opportunity taken. Viral Immunology. 2000; 13(4): 411-4. ISSN:  0882-8245.

Descriptors:   disease movement, changes in pathogenicity, adaption to U.S. climates, insect disease vectors and reservoirs, disease prevention and control, birds, Culicidae mosquitoes, virus transmission, New York City. 


Cantile, C.; G. Di Guardo; C. Eleni; M. Arispici. Clinical and neuropathological features of West Nile virus equine encephalomyelitis in Italy. Equine Veterinary Journal. Jan 2000. v. 32 (1) p. 31-35. ISSN: 0425 1644.

NAL Call No.:  SF955.E6

Descriptors: horses, encephalitis, West Nile virus, clinical aspects, pathology, outbreaks, Italy.


Cernescu, C; Nedelcu, N I; Tardei, G; Ruta, S; Tsai, T F. Continued transmission of West Nile virus to humans in southeastern Romania, 1997-1998. Journal of Infectious Diseases. 2000 Feb; 181(2): 710-2. ISSN:  0022-1899.

NAL Call No.: 448.8 J821

Descriptors:  disease transmission, monitoring for West Nile virus in sentinel chickens, seroconversion, summer months, Romania.

Abstract: After an epidemic of West Nile (WN) virus neurologic infections in southeastern Romania in 1996, human and animal surveillance were established to monitor continued transmission of the virus. During 1997 and 1998, neurologic infections were diagnosed serologically as WN encephalitis in 12 of 322 patients in 19 southeastern districts and in 1 of 75 Bucharest patients. In addition, amid a countrywide epidemic of measles, the etiology of the febrile exanthem in 2 of 180 investigated cases was determined serologically to be WN fever; 1 case was complicated by hepatitis. Sentinel chickens placed in Bucharest seroconverted to WN virus during the summer months, indicating their potential value in monitoring transmission. The continued occurrence of sporadic WN infections in southeastern Romania in consecutive years after the 1996 epidemic is consistent with local enzootic transmission of the virus.


Chiang, W K. Update on emerging infections from the Centers for Disease Control and Prevention.Update: surveillance for West Nile virus in overwintering mosquitoes--New York, 2000. Annals of Emergency Medicine. 2000 Jul; 36(1): 61-3. ISSN:  0196-0644.

Descriptors:   surveillance data, Culex mosquitoes, RNA, viral genetics, behavior of overwintering mosquitoes, insect vectors and reservoirs, New York City. 


Cooper J; Miller J; Bennett P; White D; Smith P.Update: surveillance for West Nile virus in overwintering mosquitoes - New York, 2000. MMWR Morbidity and Mortality Weekly Report. 2000, 49: 9, 178-179; 7 ref. ISSN: 0149-2195.

NAL Call No.: RA407.3 M56

Descriptors: Culex mosquitoes, virus isolates, detection of viral RNA, New York. 

Abstract:  The results of the analysis, which documented West Nile virus RNA in some Culex mosquito pools collected from structures in New York City, New York, USA between January and February 2000 are summarized. No pools prduced live virus isolates, however 67 pools containing Culex spp. mosquitoes, all of which were collected from Fort Totten, reproducibly demonstrated low but detectable levels of West Nile virus RNA.


Fio, L. Preparing for West Nile virus in California. Journal of Equine Veterinary Science. Aug 2000. v. 20 (8) p. 480, 483-484, 527. ISSN: 0737-0806.

NAL Call No.:  SF951.J65

Descriptors: horses, West Nile virus, West Nile fever, California.


Garmendia, A E; Van Kruiningen, H J; French, R A; Anderson, J F; Andreadis, T G; Kumar, A; West, A B. Recovery and identification of West Nile virus from a hawk in winter. Journal of Clinical Microbiology. 2000 Aug; 38(8): 3110-1. ISSN:  0095-1137.

NAL Call No.: QR46.J6

Descriptors:   redtailed hawk, raptor virology, analysis of brain tissue for West Nile virus, cytoplasmic vesicles, ELISA testing, transmission routes, viral reservoirs, winter season, New York.

Abstract: West Nile virus was recovered from the brain of a red-tailed hawk that died in Westchester County, N.Y., in February 2000. Multiple foci of glial cells, lymphocytes, and a few pyknotic nuclei were observed in the brain. Three to 4 days after inoculation of Vero cells with brain homogenates, cytopathic changes were detected. The presence of West Nile virus antigen in fixed cells or cell lysates was revealed by fluorescent antibody testing or enzyme-linked immunosorbent assay, respectively. Furthermore, Reverse transcriptase-PCR with primers specific for the NS3 gene of West Nile virus resulted in an amplicon of the expected size (470 bp). Electron microscopy of thin sections of infected Vero cells revealed the presence of viral particles approximately 40 nm in diameter, within cytoplasmic vesicles. The demonstration of infection with the West Nile virus in the dead of the winter, long after mosquitoes ceased to be active, is significant in that it testifies to the survival of the virus in the region beyond mosquito season and suggests another route of transmission: in this case, prey to predator.


Gough P. Discovery of West Nile virus in Connecticut and what was learned during the first year. Frontiers of Plant Science. 2000, 52: 2, 2-4. ISSN:   0016-2167.

NAL Call No.: 100 F92

Descriptors: viral isolation and identification, mosquitoes vectors, birds, Culicidae, Connecticut.


Gubler, D J; Campbell, G L; Nasci, R; Komar, N; Petersen, L; Roehrig, J T. West Nile virus in the United States: guidelines for detection, prevention, and control. Viral Immunology. 2000; 13(4): 469-75. ISSN: 0882-8245.

Descriptors:  viral disease epidemiology, diagnosis, prevention and control, disease transmission patterns, Culicidae disease vectors, viral disease reservoirs, public health guidelines for monitoring viral activity, Northeast, U.S. 

Abstract:  The epidemic/epizootic of West Nile (WN) encephalitis in the northeastern United States in the summer and fall of 1999 was an unprecedented event, underscoring the ease with which emerging infectious pathogens can be introduced into new geographic areas in today's era of rapid transportation and increased movement of people, animals, and commodities. This epidemic/epizootic and the increased frequency of other exotic pathogens being imported into the United States raises the issue of whether local, state, and national public health agencies are prepared to deal with epidemics/epizootics of vector-borne infectious diseases. The overwintering of WN virus and the epizootic transmission in the summer of 2000 reinforces the need to rebuild the public health infrastructure to deal with vector-borne diseases in this country. This article summarizes guidelines for surveillance, prevention, and control of WN virus that were drafted in December 1999 to help prepare state and local health departments for monitoring WN virus activity in the spring and summer of 2000 and also summarizes the data collected from those surveillance systems through September 2000.


Holloway, M. Outbreak not contained. West Nile virus triggers a reevaluation of public health surveillance. Scientific American. 2000 Apr; 282(4): 20, 22. ISSN:  0036-8733.

NAL Call No.: 470 Sci25

Descriptors: epidemiology, songbird surveillance, chickens, Culicidae mosquito vectors, disease prevention and control.


Hubalek, Z. European experience with the West Nile virus ecology and epidemiology: could it be relevant for the New World? Viral Immunology. 2000; 13(4): 415-26. ISSN:  0882-8245.

Descriptors:   review article, West Nile virus epidemiology, Culex pipiens biotype molestus, vector cycles, transmission and population factors, human health risks, horses, migratory birds, four component surveillance system, virus isolation and purification.  

Abstract:  A review of West Nile virus (WNV) and the epidemiology of West Nile fever (WNF) in Europe is presented. European epidemics of WNF reveal some general features. They usually burst out with full strength in the first year, but few cases are observed in the consecutive 1 to 2 (exceptionally 3) years, whereas smaller epidemics or clusters of cases only last for one season. The outbreaks are associated with high populations of mosquitoes (especially Culex spp.) caused by flooding and subsequent dry and warm weather, or formation of suitable larval breeding habitats. Urban WNF outbreaks associated with Culex pipiens biotype molestus are dangerous. Natural (exoanthropic, sylvatic) foci of WNV characterized by the wild bird-ornithophilic mosquito cycle probably occur in many wetlands of climatically warm and some temperate parts of Europe; these foci remain silent but could activate under circumstances supporting an enhanced virus circulation due to appropriate abiotic (weather) and biotic (increased populations of vector mosquitoes and susceptible avian hosts) factors. It is very probable that WNV strains are transported between sub-Saharan Africa and Europe by migratory birds. The surveillance system for WNF should consist of four main components: (1) monitoring of mosquito populations and their infection rate; (2) wild vertebrate surveys; (3) sentinel birds (domestic ducks rather than chickens); and (4) monitoring of human disease. In the case of persisting high risk of WNF for humans and equids in certain enzootic areas, immunization against WNF should be considered. For that purpose a commercially available, cross-protective vaccine against Japanese encephalitis could be used.


Jerabek J. Virova encefalitida zapadniho Nilu ohrozuje nejenom kone. [West Nile virus encephalitis not only a threat to horses. An update.] Veterinarstvi. 2000, 50: 7, 285-286; 3 ref.  ISSN: 0506-8231. In Czech.

NAL Call No.: 41.8 V6439

Descriptors:  West Nile virus, zoonotic disease, horses, humans, other animals, epidemiology.


Johnston, BL; Conly, JM. West Nile virus - where did it come from and where might it go? Canadian Journal of Infectious Diseases. 2000, 11: 4, 175-178; 30 ref.  ISSN: 1180-2332.

Descriptors:   vector borne viral diseases, incidence levels, geographic distribution, disease migration, emerging disease in North America, Canada.


Jones, W.E. West Nile virus activity northeastern United States. Journal of Equine Veterinary Science. Sept 2000. v. 20 (9) p. 552. ISSN: 0737-0806.

NAL Call No.:  SF951.J65

Descriptors: West Nile virus, disease statistics, northeastern states of USA.


Lanciotti, R S; Kerst, A J; Nasci, R S; Godsey, M S; Mitchell, C J; Savage, H M; Komar, N; Panella, N A; Allen, B C; Volpe, K E; Davis, B S; Roehrig, J 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. 2000 Nov; 38(11): 4066-71 ISSN:  0095-1137.

NAL Call No.: QR46.J6

Descriptors:  viral detection methods, NY1999 West Nile virus isolate, comparison of detection methods, sensitivity levels, Culex mosquito pools, field collected avian tissue sampling, assays, surveillance tool, Vero cells, TaqMan assay, Rt-PCR.

Abstract:  The authors report on the development and application of a rapid TaqMan assay for the detection of West Nile (WN) virus in a variety of human clinical specimens and field-collected specimens. Oligonucleotide primers and FAM- and TAMRA-labeled WN virus-specific probes were designed by using the nucleotide sequence of the New York 1999 WN virus isolate. The TaqMan assay was compared to a traditional reverse transcriptase (RT)-PCR assay and to virus isolation in Vero cells with a large number ( approximately 500) of specimens obtained from humans (serum, cerebrospinal fluid, and brain tissue), field-collected mosquitoes, and avian tissue samples. The TaqMan assay was specific for WN virus and demonstrated a greater sensitivity than the traditional RT-PCR method and correctly identified WN virus in 100% of the culture-positive mosquito pools and 98% of the culture-positive avian tissue samples. The assay should be of utility in the diagnostic laboratory to complement existing human diagnostic testing and as a tool to conduct WN virus surveillance in the United States.


Lustig, S; Halevy, M; Fuchs, P; Ben Nathan, D; Lachmi, B E; Kobiler, D; Israeli, E; Olshevsky, U. Can West Nile virus outbreaks be controlled? Israel Medical Association Journal. 2000 Oct; 2(10): 733-7. ISSN: 1565-1088.

Descriptors: disease outbreaks prevention and control, diagnosis, epidemiology, transmission patterns, virus isolation and purification, viral vaccine potential. 


Lustig, S; Olshevsky, U; Ben Nathan, D; Lachmi, B E; Malkinson, M; Kobiler, D; Halevy, M. A live attenuated West Nile virus strain as a potential veterinary vaccine. Viral Immunology. 2000; 13(4): 401-10. ISSN:  0882-8245.

Descriptors:  attenuated virus—WNI 25 and WNI 25A, neuroinvasion, traits lost, virus strain development, amino acids, potential live vaccine strain, immunology, geese, SCID mice, serial passage. 

Abstract:  This article reviews the development of two attenuated West Nile virus (WNV) variants, WNI-25 and WNI-25A. These variants have lost the neuroinvasion trait of the parental virus. Attenuation was achieved through serial passages in mosquito cells and neutralization escape from WNV-specific monoclonal antibody. Genetic analysis reveals amino acid changes between the parental and each of the variants. The attenuated variants preserve the ability to replicate in mice and geese and to induce a protective immune response. WNI-25A was found to be a genetically stable virus. This variant was successfully used as a live vaccine to protect geese against a wild-type virulent WNV field isolate that closely resembles the WNV isolated during the 1999 New York epidemic.


Miller, B R; Nasci, R S; Godsey, M S; Savage, H M; Lutwama, J J; Lanciotti, R S; Peters, C J. First field evidence for natural vertical transmission of West Nile virus in Culex univittatus complex mosquitoes from Rift Valley province, Kenya. American Journal of Tropical Medicine and Hygiene. 2000 Feb; 62(2): 240-6. ISSN: 0002-9637

Descriptors: Culex univittatus virology, disease transmission, insect vector viral reservoirs, Culex pipiens, migratory birds as disease spreaders, amino acid sequence, antigens, viral analysis, base sequence, DNA primers chemistry, electrophoresis, indirect fluorescent antibody technique, Kenya epidemiology, phylogeny, RNA, viral chemistry; RT-PCR, homology of amino acids, Vero cells, viral envelope proteins chemistry and genetics.

Abstract: West Nile virus is a mosquito borne flavivirus endemic over a large geographic area including Africa, Asia, and the Middle East. Although the virus generally causes a mild, self-limiting febrile illness in humans, it has sporadically caused central nervous system infections during epidemics. An isolate of West Nile virus was obtained from a pool of four male Culex univittatus complex mosquitoes while we were conducting an investigation of Rift Valley fever along the Kenya-Uganda border in February-March 1998. This represents the first field isolation of West Nile virus from male mosquitoes and strongly suggests that vertical transmission of the virus occurs in the primary maintenance mosquito vector in Kenya. A phylogenetic analysis of the complete amino acid sequence of the viral envelope glycoprotein demonstrated a sister relationship with a Culex pipiens mosquito isolate from Romania made in 1996. This unexpected finding probably reflects the role of migratory birds in disseminating West Nile virus between Africa and Europe.


Murray-Kristy O; Komar N; McLean R; Glaser L; Eidson M; Sorhage F; Nelson R; Mostashari F; Khan A; Rotz L; Gubler D. Multi-state, multi-jurisdictional avian mortality surveillance as a detection method for geographical spread and reemergence of West Nile virus. American Journal of Epidemiology. June 1, 2000; 151 (11 Supplement): S91. ISSN:  0002-9262. Note: 33rd Annual Meeting of the Society for Epidemiologic Research, Seattle, Washington, USA, June 15-17, 2000.

NAL Call No.: 449.8 Am3

Descriptors:  bird mortality levels, geographic pattern of disease spread, disease dissemination, usefulness of detection method, multi-state surveillance system, U.S.


Nolen, RS. West Nile virus survives winter; no surprise, says CDC. Journal of the American Veterinary Medical Association. 2000 Apr 15; 216(8): 1199-1200. 2000 Sep 15; 217(6): 812. 0003-1488.

NAL Call No.: 41.8 Am3

Descriptors:  disease vector reservoirs, overwintering of Culex mosquitoes, transmission patterns, migratory birds, raptors, New York, Connecticut.


Nolen, RS. Multistate surveillance system in place for West Nile virus. Journal of the American Veterinary Medical Association. 2000 Jan 1; 216(1): 11. ISSN: 0003-1488.

NAL Call No.: 41.8 Am3

Descriptors: sentinel bird surveillance, songbirds, epidemiology, horses, vector mosquitoes, disease transmission patterns, control and prevention, surveillance system, Mid-Atlantic region, USDA/CDC.


Novello, AC. West Nile virus in New York State: the 1999 outbreak and response plan for 2000. Viral Immunology. 2000; 13(4): 463-7. ISSN: 0882-8245.

Descriptors: bird mortality, disease reservoirs, epidemiology, mosquito vectors of disease, vector control, sentinel  surveillance, virus isolation and purification.


Quarles, W. West nile encephalitis--again. Common Sense Pest Control Quarterly. Summer 2000. v. 16 (3) p. 4-5. ISSN: 8756-7881.

NAL Call No.:  SB950.A1C62

Descriptors: West Nile virus, wild birds, sentinel animals, outbreaks, insect control, public health, USA.


Rappole, JH; Derrickson, SR; Hubalek, Z. Migratory birds and spread of West Nile virus in the Western Hemisphere. Emerging Infectious Diseases. 2000 Jul-Aug; 6(4): 319-28. ISSN:  1080-6040.

NAL Call No.: RA648.5 E46

Descriptors:  disease introduction into U.S., amplifying agents, vectors, arnithophilic mosquitoes, viremic migratory birds, disease spread, transovarial transmission, overwintering mosquitoes, viral disease persistence, New York, migratory birds, epidemiology, Western hemisphere. 

Abstract:  West Nile virus, an Old World flavivirus related to St. Louis encephalitis virus, was first recorded in the New World during August 1999 in the borough of Queens, New York City. Through October 1999, 62 patients, 7 of whom died, had confirmed infections with the virus. Ornithophilic mosquitoes are the principal vectors of West Nile virus in the Old World, and birds of several species, chiefly migrants, appear to be the major introductory or amplifying hosts. If transovarial transmission or survival in overwintering mosquitoes were the principal means for its persistence, West Nile virus might not become established in the New World because of aggressive mosquito suppression campaigns conducted in the New York area. However, the pattern of outbreaks in southern Europe suggests that viremic migratory birds may also contribute to movement of the virus. If so, West Nile virus has the potential to cause outbreaks throughout both temperate and tropical regions of the Western Hemisphere.


Ritchie, B.W. West Nile virus--a recent immigrant to the United States. Compendium on Continuing Education for the Practicing Veterinarian. June 2000. v. 22 (6) p. 576-587. ISSN: 0193-1903.

NAL Call No.:  SF601.C66

Descriptors: West Nile virus, zoonoses, disease vectors, mosquito borne diseases, wild birds, viremia, mammals, disease distribution and spread.


Senne, D.A.; J. Pedersen; D. Hutto; W. Taylor; B. Schmitt; B. Panigrahy. Pathogenicity of West Nile virus in chickens. Avian Diseases. July/Sept 2000. v. 44 (3) p. 642-649. ISSN: 0005-2086.

NAL Call No.:  41.8 Av5

Descriptors: chickens, pathogenicity, West Nile virus, clinical aspects, viremia, lesions, histopathology, animal tissues, disease transmission, immune response, experimental infections.

Abstract: In the fall of 1999, West Nile virus (WNV) was isolated for the first time in the Western Hemisphere during an outbreak of neurologic disease in humans, horses, and wild and zoo birds in the northeastern United States. Chickens are a potential reservoir for WNV, and little is known about the pathogenicity of WNV in domestic chickens. Seven-week-old chickens derived from a specific-pathogen-free flock were inoculated subcutaneously with 1.8 x 10(3) 50% tissue culture infectious dose of a crow isolate of WNV in order to observe clinical signs and evaluate the viremic phase, gross and microscopic lesions, contact transmission, and immunologic response. There were no observable clinical signs in the WNV-inoculated chickens during the 21-day observation period. However, histopathologic examination of tissues revealed myocardial necrosis, nephritis, and pneumonitis at 5 and 10 days postinoculation (DPI); moderate to severe nonsuppurative encephalitis also was observed in brain tissue from one of four inoculated birds examined at 21DPI. WNV was recovered from blood plasma for up to 8 DPI. Virus titers as high as 10(5)/ml in plasma were observed at 4 DPI. Fecal shedding of virus was detected in cloacal swabs on 4 and 5 DPI only. The WNV also was isolated from myocardium, spleen, kidney, lung, and intestine collected from chickens euthanized at 3, 5, and 10 DPI. No virus was isolated from inoculated chickens after 10 DPI. Antibodies specific to WNV were detected in inoculated chickens as early as 5 DPI by the plaque reduction neutralization test and 7DPI by the indirect fluorescent antibody test. Chickens placed in contact with inoculated chickens at 1 DPI lacked WNV-specific antibodies, and no WNV was isolated from their blood plasma or cloacal swabs throughout the 21 days of the experiment.


Steele, K.E.; M. Linn; R. Schoepp; N. Komar; T. Geisbert; R. Manduca; P. Calle; B. Raphael; T. Clippinger; T. Larsen. Pathology of fatal West Nile virus infections in native and exotic birds during the 1999 outbreak in New York City, New York. Veterinary Pathology. May 2000. v. 37 (3) p. 208-224. ISSN: 0300-9858.

NAL Call No.:  41.8 P27

Descriptors: wild birds, introduced species, West Nile virus, infections, outbreaks, horses, man, wildlife, postmortem examinations, histopathology, tissue ultrastructure, detection, immunohistochemistry, DNA hybridization, polymerase chain reaction, brain, heart, spleen, liver, kidneys, adrenal glands, intestines, pancreas, lungs, ovaries, macrophages, monocytes, epithelium, cross-reaction, diagnostic techniques, evaluation, flavivirus, New York City.


Steffanus, D. West Nile virus attacks U.S. horses. Equine Practitioner. Jan 2000. v. 22 (1) p. 22-23. ISSN: 0162-8941.

NAL Call No.:  SF951.E62

Descriptors: horses, West Nile virus, encephalitis, New York.


Studdert, M.J. West Nile virus finds a new ecological niche in Queens, New York. Australian Veterinary Journal. 1927. June 2000. v. 78 (6) p. 400-401. ISSN: 0005-0423.

NAL Call No.:  41.8 Au72

Descriptors: West Nile virus, disease control, birds, man, Culicidae, horses, disease transmission, disease surveys, monitoring, epidemiology, New York City.


Swayne, D E; Beck, J R; Zaki, S. Pathogenicity of West Nile virus for turkeys. Avian Diseases. 2000 Oct-Dec; 44(4): 932-7. ISSN: 0005-2086.

NAL Call No.: 41.8 Av5

Descriptors:  domestic and wild strains of turkeys, pathogenicity in turkeys, crow tissue, experimental infection, viremic levels in various tissues, risk analysis, not a major disease for turkeys.  

Abstract:  In the fall of 1999, West Nile virus (WNV) was isolated during an outbreak of neurologic disease in humans, horses, and wild and zoological birds in New York, Connecticut, and New Jersey. Turkeys could potentially be a large reservoir for WNV because of the high-density turkey farming and the presence of large wild turkey populations in the eastern seaboard of the United States. Little is known about the pathogenicity of WNV in domestic or wild turkeys. Specific-pathogen-free 3-wk-old turkeys were inoculated subcutaneously with 10(3.3) mean tissue culture infective doses of a WNV strain isolated fromthe index case in a New York crow. No clinical signs were observed in the turkeys over the 21 days of the experiment. One turkey died abruptly at 8 days postinoculation (DPI). Many turkeys developed viremia between 2 and 10 DPI, but the average level of virus was very low, less than needed to efficiently infect mosquitos. Low levels of WNV were detected in feces on 4 and 7 DPI, but no virus was isolated from oropharyngeal swabs. WNV wasnot transmitted from WNV-inoculated to contact-exposed turkeys. All WNV-inoculated poults seroconverted on 7 DPI. In the turkey that died, WNV was not isolated from intestine, myocardium, brain, kidney, or cloacal and oropharyngeal swabs, but sparse viral antigen was demonstrated by immunohistochemistry in the heart and spleen. Turkeys in contact with WNV-inoculated turkeys and sham-inoculated controls lacked WNV specific antibodies,and WNV was not isolated from plasma and cloacal and oropharyngeal swabs. These data suggest that WNV lacks the potential to be a major new disease of turkeys and that turkeys will not be a significant amplifying host for infecting mosquitos.


Turell, M J; O'Guinn, M; Oliver, J. Potential for New York mosquitoes to transmit West Nile virus. American Journal of Tropical Medicine and Hygiene. 2000 Mar; 62(3): 413-4. ISSN:  0002-9637.

NAL Call No.: 448.8 Am326

Descriptors:  Culicidae mosquitoes, insect vectors virology, disease transmission, isolation and purification, chickens, New York City, Culex pipiens, Aides vexans, oral infection, feeding study.

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 (1999) WN outbreak were allowed to feed on chickens infected with WN virus isolated from a crow that had died during this outbreak. These mosquitoes were tested approximately 2 weeks later to determine infection, dissemination, and transmission rates. Culex pipiens mosquitoes were highly susceptible to infection, and nearly all individuals with a disseminated infection did transmit WN virus by bite. In contrast, Aedes vexans were only moderately susceptible to oral infection; however, those individuals inoculated with WN virus did transmit virus by bite.


van der Poel, W H. De verspreiding van west Nile virus, voorbij New York 2000. [The spread of the West Nile virus, past New York 2000.] Tijdschrift voor Diergeneeskunde. 2000 Sep 1; 125(17): 526-7. ISSN: 0040-7453.

NAL Call No.: 41.8 T431

Descriptors:  disease dissemination, birds as disease reservoirs, Culicidae, mosquito vector control, epidemiology, New York, prevention and control.


Zientara S. Le virus West Nile, un arbovirus reemergent en Europe? [The West Nile virus, a re-emerging arbovirus in Europe?] Equ'Idee. 2000, No. 39, 25-26.

ISSN: 1162-8103. In French.

Descriptors: horses, birds, insect vectors, detection by ELISA, Europe, France, risk of re-emergence. 

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February 10, 2003