West Nile Virus

Ben-Nathan, D; Lustig, S; Feuerstein, G. The influence of cold or isolation stress on neuroinvasiveness and virulence of an attenuated variant of West Nile virus. Archives of Virology. 1989; 109(1-2): 1-10. ISSN: 0304-8608.

Descriptors: stress effects on pathogenicity and neuroinvasion, mouse model, attenuated WNV strain, I.P. injection, cold and isolation stressors, change in strain virulence.

Abstract: The effect of cold or isolation stress on neuroinvasiveness and virulence was investigated in mice inoculated with an attenuated WNV (WN-25) strain. The WN-25 variant differed from the parent strain by its inability to kill mice after I.P. injection though it was able to immunize even after injection with low doses of virus. Exposure of inoculated mice for 5 minutes a day to cold water (1 +/- 0.5 degrees C) for 8 days resulted in 60% mortality, while in nonstressed infected mice no death was observed. Cold or isolation stress increased the virus level in the brain to 8.9 and 7.4 log 10 PFU as compared to no virus in the infected control. Moreover, it was found that virus level in the spleen of stressed mice reached 3.4 and 3.7 log 10 PFU respectively, while in non-stressed mice no virus was detected. The virus which was isolated from the brain of moribund stressed mice was extremely virulent: I.P. inoculation of as little as 10 PFU caused death to normal non-stressed mice. We suggest that cold or isolation stress conditions in mice inoculated with an attenuated strain induce a selection process. The virus which was isolated from the brain of stressed mice changes its virulence and kills like wild type WNV.

Blackburn, N.K.; F. Reyers; W. Berry; A. Shepherd. Susceptibility of dogs to West Nile virus: a survey and pathogenicity trial. Journal of Comparative Pathology. Jan 1989. v. 100 (1) p. 59-66. ISSN: 0021-9975.

Descriptors: dogs, flavivirus, susceptibility, disease resistance, pathogenicity, disease surveys, epidemiology, South Africa.

Fontenille, D; Rodhain, F; Digoutte, JP; Mathiot, C; Morvan, J; Coulanges, P. Les cycles de transmission du virus West-Nile a Madagascar, Ocean Indien. [Transmission cycles of the West-Nile virus in Madagascar, Indian Ocean]. Annales de la Societe Belge de Medecine Tropicale. 1989 Sep; 69(3): 233-43. ISSN: 0365-6527. In French.

Descriptors: humans and birds, oxen, bats, rodents, lemurs, mosquito disease vectors, Culex decens, Culex quinquefasciatus, Culex antennatus, Culex univittatus, Aedes, Anopheles, disease prevalence, serological testing, vertebrate hosts, transmission cycles.

Abstract: Virological, serological and entomological research conducted in Madagascar since 1975, reveal the wide-spread presence of West-Nile virus on the island. This arbovirus has been isolated from humans, parrots and egrets. Vectors belong to the genus Culex (e.g. Cx. decens, Cx. quinquefasciatus, Cx. antennatus, Cx. univittatus), however the virus has also been isolated from Aedes and Anopheles. Serological tests carried out on over 1,600 human and almost 1,000 animal sera, revealed that human beings could be infected throughout the island. Other potential vertebrate hosts, apart from birds, are oxen and bats. Insectivores, rodents and lemurs are probably involved in the transmission cycles only to a very small extent.

King, NJ; Maxwell, LE; Kesson, AM. Induction of class I major histocompatibility complex antigen expression by West Nile virus on gamma interferon-refractory early murine trophoblast cells. Proceedings of the National Academy of Sciences of the United States of America. 1989 Feb; 86(3): 911-5. ISSN: 0027-8424.

Descriptors: maternal and/or species protective evolution, implanting semi-allogeneic embryo, major histocompatibity complex.

Abstract: Primary murine trophoblast giant cells (TGC) do not express detectable major histocompatibility complex (MHC) antigens and are refractory to the MHC-increasing effects of alpha and beta (virus-induced) interferons and gamma (immune type) interferon during early implantation (postcoital days 3.5-6). West Nile virus infection of primary TGC monolayers from postcoital-day-3.5 preimplantation blastocysts induced paternal MHC antigen expression within 16 hr, as detected by immunogold labeling for electron microscopy. Induction is unlikely to have been mediated by secreted virus-induced interferons or other factors, as it occurred in the presence of high concentrations of anti-alpha/beta interferon antibodies and was not induced by virus-inactivated supernatants from MHC-induced primary TGC cultures. Attempts to induce MHC antigen expression with poly(I.C) or recombinant tumor necrosis factor alpha in primary TGC cultures also failed. Thus, the apparent inhibition of MHC antigen expression in primary TGC during early implantation and their refractoriness to induction of de novo MHC antigen expression is not absolute. This may represent a maternal-and/or species-protective evolutionary device. As such, manipulation of this phenomenon may allow a conclusive assessment of the significance of inhibition of MHC antigen expression on trophoblast cells in the implanting semiallogeneic embryo.

Liu, Y; Blanden, RV; Mullbacher, A. Identification of cytolytic lymphocytes in West Nile virus-infected murine central nervous system. Journal of General Virology. 1989 Mar; 70 ( Pt 3): 565-73. ISSN: 0022-1317.

Descriptors: inflammatory cells, CBA/H (H-2k) mouse brains, cell surface markers, lymphocytes detected, T cells, natural killer cells, 2-color flow cytometry.

Abstract: Inflammatory cells were isolated from West Nile virus (WNV)-infected CBA/H (H-2k) mouse brains, and their function and cell surface markers were studied. Two populations of cytolytic lymphocytes were detected. One population, which lysed WNV-infected and uninfected L929 (H-2k), YAC-1 (H-2a), P815 (H-2d), OH (H-2KdDk) and 2R (H-2KkDb) target cells, had a phenotype of L3T4- Lyt2- Thy1 +/- asialo GM1+ and hence were natural killer (NK) cells. The other, which lysed WNV-infected cells to a greater extent than uninfected L929 cells, had a phenotype of L3T4- Lyt2+ Thy1+ asialo GM1- and were cytotoxic T cells. In addition, the presence of the latter population was demonstrated by the specific lysis of syngeneic WNV-infected astrocytes, a cell type which is resistant to NK cell lysis. The cell surface markers of isolated inflammatory cells were determined by two colour flow cytometry. This showed that 15 to 40% of the cells were Thy1+, among which about 3% were Lyt2+. No L3T4+ cells were detected.

Nowak, T; Farber, PM; Wengler, G; Wengler, G. Analyses of the terminal sequences of West Nile virus structural proteins and of the in vitro translation of these proteins allow the proposal of a complete scheme of the proteolytic cleavages involved in their synthesis. Virology. 1989 Apr; 169(2): 365-76.ISSN: 0042-6822.

Descriptors: proteolytic processe, synthesis of the structural proteins, West Nile virus, anchored C protein, cleavage of pre-M protein residues 215-216, animo-terminal fragment loss, release of virus from cells.

Abstract: The proteolytic processes involved in the synthesis of the structural proteins of the West Nile (WN) flavivirus were analyzed: The carboxy-terminal sequences of the structural proteins were determined and the proteins translated in vitro in the presence of membranes from a mRNA coding for the structural polyprotein were analyzed. The results obtained indicate that the following proteolytic activities are involved in the synthesis and assembly of WN virus structural proteins: The growing peptide chain which contains the sequences of the structural proteins in the order C-pre-M-E is cleaved at three places by cellular signalase(s). This cleavage generates the primary amino acid sequence of the mature structural proteins pre-M and E (and the amino-terminus of the ensuing nonstructural protein NS 1). The amino-terminal part of the polyprotein containing the amino acid residues 1 to 123 is released as a molecule which migrates slightly slower than the mature viral core protein and which presumably is associated to the RER membranes via its carboxy-terminal sequence. This protein is called the anchored C virus particles the anchored C protein is converted into mature C protein by removal of the carboxy-terminal hydrophobic segment containing the amino acid residues 106 to 123. Presumably a virus-coded protease which can cleave the polyprotein after two basic amino acid residues is responsible for this cleavage. The cell-associated WN virus particles are constructed from the proteins C, pre-M, and E which contain the amino residues 1-105, 124-290, and 291-787 of the polyprotein, respectively. Cleavage of the pre-M protein between amino acid residues 215 and 216, presumably by a cellular enzyme located in the Golgi vesicles, and loss of the amino-terminal fragment of this protein are associated with the release of virus from the cells.

Wengler, G; Wengler, G. An analysis of the antibody response against West Nile virus E protein purified by SDS-PAGE indicates that this protein does not contain sequential epitopes for efficient induction of neutralizing antibodies. Journal of General Virology. 1989 Apr; 70 ( Pt 4): 987-92. ISSN: 0022-1317.

Descriptors: E-protein analysis, neutralizing epitopes generated from linear segments of the protein.

Abstract: The large envelope (E) protein of flaviruses is the viral surface protein that contains neutralizing epitopes. We have analysed the E protein of the West Nile (WN) flavivirus for neutralizing epitopes generated from linear segments of the protein; if effective, these might allow the synthesis of peptides suitable for vaccination. For this study we used the E protein and defined fragments thereof as antigens in rabbits. The sera thus obtained, containing antibodies to E protein as shown by Western blot analyses, were tested for neutralizing activity by the plaque reduction neutralization test. If the E protein used as antigen was reduced (the native E protein contains six disulphide bridges) and denatured the resulting antibodies did not consistently demonstrate neutralizing activity. These results show that the E protein of WN virus does not contain a linear segment that is able to induce neutralizing antibodies efficiently. Studies using denatured E protein fragments containing subsets of the intact disulphide bridges showed that the local covalent primary structure of the protein involved in each of the six bridges was also insufficient for inducing the synthesis of neutralizing antibodies. The complete E protein, with all six disulphide bridges intact, purified by preparative SDS-PAGE under the conditions used in our experiments could, however, induce the synthesis of neutralizing antibodies in rabbits. These data indicate that at least one complex epitope which is able to induce neutralizing antibodies is not completely denatured or can be reformed to some extent if the complete E protein has been subjected to SDS-PAGE without prior destruction of the disulphide bridges.

Besselaar, TG; Blackburn, NK. Antigenic analysis of West Nile virus strains using monoclonal antibodies. Archives of Virology. 1988; 99(1-2): 75-88. ISSN: 0304-8608.

Descriptors: antigenic identification, 17 MAbs, WNV H442, indirect immunofluorescence, 17 isolates, strain comparisons.

Abstract: Seventeen monoclonal antibodies (MAbs) were prepared against the flavivirus West Nile strain H442. While the majority of these were specific for the major envelope protein, MAbs directed against the NS1 and ns4a nonstructural proteins were also identified. The MAbs were tested by indirect immunofluorescence against 16 southern African West Nile (WN) isolates, representative strains from the two main WN antigenic groups and several viruses from other flavivirus complexes. The MAb reactivities ranged from WN strain-specific to broadly flavivirus-group reactive. Comparison of the local isolates revealed the presence of several different strains, all of which were antigenically distinct from the representative strains of the two WN antigenic groups.

Grun, JB; Brinton, MA. Separation of functional West Nile virus replication complexes from intracellular membrane fragments. Journal of General Virology. 1988 Dec; 69 ( Pt 12): 3121-7.ISSN: 0022-1317.

Descriptors: protein functions, viral replication complexes, endoplasmic reticular membranes, ultra-pure detergents--Tween 20, maltoside, octylglucoside, lubrol PX and sodium deoxycholate tested, sodium deoxycholate, effects on polymerase activity and replication.

Abstract: Flaviviruses encode seven non-structural proteins for which functions have not yet been described. The identification of the viral and possible host proteins which may be involved in flavivirus replication has been impeded by the fact that the viral replication complexes are tightly associated with endoplasmic reticular membranes within infected cells and that in vitro polymerase activity is associated with large membrane fragments. To facilitate further study of flavivirus replication complexes, selected ultrapure detergents were analysed for their effect on West Nile virus (WNV) in vitro RNA-dependent RNA polymerase activity and for their ability to release functional replication complexes from partially purified intracellular BHK-21 membrane fragments. A few previous reports indicated that flavivirus in vitro polymerase activity was sensitive to detergent treatment. The present study indicates that WNV polymerase activity is variably inhibited depending on the concentration and identity of the detergent used. Of the five detergents (Tween 20, maltoside, octylglucoside, lubrol PX and sodium deoxycholate) tested, sodium deoxycholate was the most efficient at releasing functional viral replication complexes from intracellular membranes.

Liu, Y; King, N; Kesson, A; Blanden, RV; Mullbacher, A. West Nile virus infection modulates the expression of class I and class II MHC antigens on astrocytes in vitro. Annals of the New York Academy of Sciences. 1988; 540: 483-5. ISSN: 0077-8923.

Sixl, W; Stunzner, D; Withalm, H. Serological examinations for antibodies against West Nile virus, Semlikivirus and chikungunyavirus in laboratory mice, parasitized by nidicole fauna from swallow's nests. Geographia Medica. Supplement. 1988; 1: 51-5. ISSN: 0866-4323.

Descriptors: Hirundo rustica, experimental exposure, nidicole ectoparasites, West Nile virus immunity, infection pathway, migrating birds, insect vectors.

Abstract: Experimental mice in swallow's (NMRI) nests highly infested with swallow bugs (Hirundo rustica) revealed antibodies against West Nile virus, Semliki virus and Chikungunya virus. Additional nidicole ectoparasites were not controlled and could also play a role in the occurrence of infection in experimental mice. Swallows and sparrows (Passer domesticus) additional nest inhabitants appear to be the ultimate link in this infection pathway as swallow bugs seldom migrate into dwellings to infest humans. RMSF-group antibodies and antibodies against ornithosis are rather seldom found. The import of West Nile virus, Chikungunya virus and Semliki virus to Austria through bug-parasitized swallows or other nidicole mites and insects can be assumed based on the presented results.

Castle, E; Wengler, G . Nucleotide sequence of the 5'-terminal untranslated part of the genome of the flavivirus West Nile virus. Archives of Virology. 1987; 92(3-4): 309-13. ISSN: 0304-8608.

Descriptors: RNA, nucleotide sequence, primer extension method, genome analysis, translation.

Abstract: We have determined the nucleotide sequence of the 5'-terminal untranslated region of the 42 S genome RNA of the flavivirus West Nile virus by primer extension. These analyses make our primary structure determination of this genome, which comprises a total number of 10,960 nucleotides, complete. Some implications of our data concerning the structure of flavivirus-specific nucleic acids and the initiation of translation of WN virus-specific RNA are discussed.

Grun, JB; Brinton, MA. Dissociation of NS5 from cell fractions containing West Nile virus-specific polymerase activity. Journal of Virology. 1987 Nov; 61(11): 3641-4. ISSN: 0022-538X.

Descriptors: replication complex, centrifugation, glycerol cushion, NS5, polymerase activity.

Abstract: West Nile virus replication complexes were partially purified from cytoplasmic extracts of virus-infected cells by centrifugation through a 20% glycerol cushion. Numerous cell proteins, as well as the largest nonstructural protein, NS5, were separated from the replication complexes without significant loss of in vitro West Nile virus polymerase activity.

Cardosa, MJ; Gordon, S; Hirsch, S; Springer, TA; Porterfield, JS. Interaction of West Nile virus with primary murine macrophages: role of cell activation and receptors for antibody and complement. Journal of Virology. 1986 Mar; 57(3): 952-9. ISSN: 0022-538X.

Descriptors: WNV growth, mouse primary peritoneal macrophages (resident, thioglycolate elicited, and Mycobacterium bovis BCG activated) and in macrophagelike (P338D1) and nonmacrophage (L929, PS clone D) cell lines, infected with and without IgG, IgM antibodies and complement, virus yield, factor of interaction between virus and primary macrophages.

Abstract: We have measured growth of West Nile virus in mouse primary peritoneal macrophages (resident, thioglycolate elicited, and Mycobacterium bovis BCG activated) and in macrophagelike (P338D1) and nonmacrophage (L929, PS clone D) cell lines infected in the absence or presence of specific antibodies (immunoglobulin G ([IgG], IgM), and complement. Monoclonal antibodies directed against Fc receptors (IgG1/2b, 2.4G2) and type 3 complement receptors (Mac-1) were used to define the role of each receptor. Virus yield depended on a balance between enhancement and neutralization and was influenced by the physiologic state of the macrophage, the receptor pathway of viral entry, the mouse strain and age of donor. BCG-activated macrophages displayed a greater ability to restrict West Nile virus than nonactivated cells only in the presence of antiviral IgM, with or without complement; the Fc receptors for various classes of IgG mediated striking enhancement. These studies identify some of the complex innate and acquired factors that determine the interaction between West Nile virus and primary macrophages in vitro.

Grun, JB; Brinton, MA. Characterization of West Nile virus RNA-dependent RNA polymerase and cellular terminal adenylyl and uridylyl transferases in cell-free extracts. Journal of Virology. 1986 Dec; 60(3): 1113-24. ISSN: 0022-538X

Descriptors: RNA systhesis, no labeling of WNV RNA detected with enzymes, transferase, polymerase.

Abstract: To facilitate further studies of flavivirus transcription, cell extraction methods and in vitro reaction conditions which increased West Nile virus (WNV) RNA-dependent RNA polymerase activity were determined. Subcellular fractions from WNV-infected BHK-21/W12 cells were characterized with regard to their protein and RNA content and in vitro polymerase activity. In both a cytoplasmic fraction, designated S1, and a fraction enriched for outer nuclear membranes, designated S2, seven virus-specific proteins, NS5 (96 kilodaltons [kDa]), NS3 (67 kDa), E (48 kDa), NS1 (47 kDa), ns4a (26 kDa), ns2a (17 kDa), and ns2b (14.5 kDa), were detected. The fractions also contained virus-specific RNA and cellular rRNA and mRNA. Polymerase activity in S1 and S2 fractions from WNV-infected cells was concentrated by pelleting and consisted of two types of enzyme activities: the WNV RNA-dependent RNA polymerase and terminal transferases of cellular origin. Enhanced levels of WNV polymerase activity were obtained from these cell fractions by altering several of the in vitro reaction conditions. Although Mg2+ was the divalent cation preferred by WNV polymerase, virus-specific in vitro transcription was detected at reduced levels when Mn2+ (0.05 or 0.5 mM) was present as the sole divalent cation. Product analysis revealed that the viral polymerase incorporated radiolabeled ribonucleotides into three distinct RNA species. Free single-stranded genome-sized RNA which was LiCl insoluble and RNase sensitive was found by fingerprint analysis to have an oligonucleotide pattern similar to that of WNV genomic RNA. RNA molecules which comigrated as a broad band near the top of the gel were separable into LiCl-insoluble, partially RNase-sensitive replicative-intermediate RNA and LiCl-soluble, RNase-resistant replicative-form RNA. The cellular transferases added UMP or AMP residues to the 3'-termini of cellular mRNA, tRNA, and 18S and 28S rRNA. Although a cellular terminal transferase has been reported to function in initiation of poliovirus transcription, no labeling of the WNV RNA by either of these cellular enzymes was detected. Therefore, they appear to play no specific role in flavivirus RNA synthesis.

Jupp, PG; Blackburn, NK; Thompson, DL; Meenehan, GM. Sindbis and West Nile virus infections in the Witwatersrand-Pretoria region. South African Medical Journal. 1986 Aug 16; 70(4): 218-20. ISSN: 0038-2469.

Descriptors: viral activity, Culex univittatus-bird transmission cycle, level of infection in humans, mosquito insect vector levels, South Africa.

Abstract: From mid-December 1983 until mid-April 1984, there was an epidemic of Sindbis (SIN) virus infection in the Witwatersrand-Pretoria region in which hundreds of human cases were diagnosed clinically. Twenty-eight of these diagnoses were confirmed in the laboratory by seroconversion as being infections with SIN virus, and 5 cases of infection with West Nile (WN) virus were also found. Attempts to isolate virus from 66 patients, mainly from serum specimens, were unsuccessful. Infection rates for the mosquito vector Culex univittatus, collected at localities on the Witwatersrand in February and March, were mostly higher for both SIN and WN viruses than in previous years. The highest rates determined were 5.4 (SIN) and 9.6 (WN) per 1 000 mosquitoes. It is concluded that an epizootic of both viruses occurred which was manifested by a high level of viral activity in the feral Cx. univittatus-bird transmission cycle. Cx. univittatus efficiently transferred infection of SIN virus from this cycle to man to cause the epidemic of infection with that virus but it is unclear why there were apparently only a few cases of WN virus infection.

Kimura, T; Gollins, SW; Porterfield, JS. The effect of pH on the early interaction of West Nile virus with P388D1 cells. Journal of General Virology. Nov; 67 ( Pt 11): 2423-33. ISSN: 0022-1317.

Descriptors: mouse cell line—P388D1, transmission electron microscopy, radiobinding assay, viral envelope surface protein, low pH values.

Abstract: The interaction between the flavivirus West Nile virus (WNV) and cells of the mouse macrophage-like cell line, P388D1, was assayed by transmission electron microscopy, by following the association of [35S]methionine-labelled virus with cells, and by using a radiobinding assay with an 125I-labelled F(ab')2 fragment of a monoclonal antibody directed against the major viral envelope surface glycoprotein. Using electron microscopy, both fusion and endocytosis were observed at pH 6.4, but at pH 8.0 only endocytosis was observed. When 35S-labelled WNV was bound to the P388D1 cell surface at 0 degrees C, less virus eluted on warming to 37 degrees C at mildly acidic than at alkaline or neutral pH values. The monoclonal antibody fragment had an increased affinity for cell surface viral E glycoprotein after prebound WNV was warmed at mildly acidic pH values. It is proposed that the warming of cell-virus mixtures at low pH results in fusion with a consequent reduction in elution of virus and an increase in the recognition of cell surface-expressed viral envelope glycoprotein by labelled antibody.

Kostiukov, MA; Alekseev, AN; Bulychev, VP; Gordeeva, ZE. Eksperimental'nye dokazatel'stva zarazheniia komarov Culex pipiens L. virusom likhoradki Zapadnogo Nila na ozernykh liagushkakh Rana ridibunda Pallas i peredachi ego cherez ukus. [Experimental evidence for infection of Culex pipiens L. mosquitoes by West Nile fever virus from Rana ridibunda Pallas and its transmission by bites]. Meditsinskaia Parazitologiia i Parazitarnye Bolezni. 1986 Nov-Dec; (6): 76-8. ISSN: 0025-8326. In Russian

Descriptors: frogs as a viral reservoir, Culex pipiens as insect vector, virus transmission.

Brinton, MA; Davis, J; Schaefer, D. Characterization of West Nile virus persistent infections in genetically resistant and susceptible mouse cells. II. Generation of temperature-sensitive mutants. Virology. 1985 Jan 15; 140(1): 152-8. ISSN: 0042-6822.

Descriptors: mouse embryofibroblast cell cultures, C3H/HE mice, congenic-resistant C3H/RV mice, cultural temperature effects, persistence of infections.

Abstract: Long-term persistent infections were established with the flavivirus, West Nile virus (WNV), strain E101, in embryofibroblast cultures derived from susceptible C3H/HE and congenic-resistant C3H/RV mice. Cultures were initially maintained by weekly subculture at 37 degrees, but at passage 6 sister cultures were shifted to 32 degrees. Virus progeny titers were observed to increase after the shift to 32 degrees indicating the possible presence of temperature-sensitive mutants. Temperature-sensitive mutants were found to arise in cultures of both susceptible and resistant cells. However, only in the resistant cultures did temperature-sensitive virus become the majority population. Temperature-sensitive mutants did not appear to be essential for either initiation or maintenance of WNV-persistant infections. The resistant cells appear to provide an environment which is advantageous for the amplification of temperature-sensitive mutants.

Castle, E.; T. Nowak; U. Leidner; G. Wengler. Sequence analysis of the viral core protein and the membrane-associated proteins V1 and NV2 of the flavivirus West Nile virus and of the genome sequence for these proteins. Virology. Sept 1985. v. 145 (2) p. 227-236. ill. ISSN: 0042-6822.

Descriptors: flavivirus, genomes, sequences, membranes, proteins, West Nile virus.

Kostiukov, MA; Gordeeva, ZE; Bulychev, VP; Nemova, NV; Daniiarov, OA. Ozernaia liagushka (Rana ridibunda)--odin iz prokormitelei krovososushchikh komarov Tadzhikistana--rezervuar virusa likhoradki Zapadnogo Nila. [The lake frog (Rana ridibunda)--one of the food hosts of blood-sucking mosquitoes in Tadzhikistan--a reservoir of the West Nile fever virus.] Meditsinskaia Parazitologiia i Parazitarnye Bolezni. 1985 May-Jun; (3): 49-50. ISSN: 0025-8326. In Russian.

Descriptors: disease reservoirs, frogs, Rara ridibunda, insect vectors, transmission, disease cycles, Russia.

Liapustin, VN; Chunikhin, SP; Gritsun, TS; Reshetnikov, IA; Lashkevich, VA. Osobennosti sinteza belkov virusa Zapadnogo Nila i kharakter infektsii v kletkakh mokara i mlekopitaiushchego. [Characteristics of protein synthesis in the West Nile virus and the nature of infection in mosquito and mammalian cells.] Meditsinskaia Parazitologiia i Parazitarnye Bolezni. 1985 May-Jun; (3): 50-4. ISSN: 0025-8326. In Russian.

Descriptors: WNV, mammalian and insect cell cultures, viral proteins, protein synthesis, infective process.

Lustig, S; Halevy, M; Akov, Y; Shapira, A. Attenuation of West-Nile virus in persistently West-Nile virus-infected mosquito cell culture. Israel Journal of Medical Sciences. 1985; 21 (2): 182. ISSN: 0021-2180. Annual Meeting of the Israel Society of Microbiology, Ramat Gan, Israel, Dec. 24-25, 1984.

Descriptors: mosquito cells, cell culture passages, effects of culture on pathogenicity.

Wengler, G; Castle, E; Leidner, U; Nowak, T; Wengler, G. Sequence analysis of the membrane protein V3 of the flavivirus West Nile virus and of its gene. Virology. 1985 Dec; 147(2): 264-74 .ISSN: 0042-6822.

Descriptors: membrane-associated protein V3, hemagglutination, amino acid sequences, coding area for protein, unglycosylated protein, protein synthese, endoplasmic reticulum membrane.

Abstract: Flaviviruses contain a large membrane-associated protein V3, having a mol mass of about 50 kDa which is responsible for hemagglutination. We have isolated the V3 protein from the West Nile (WN) flavivirus and determined its amino-terminal amino acid sequence and amino acid sequences of fragments derived from this protein. We have also transcribed parts of the WN virus genome RNA into cDNA and cloned and sequenced this cDNA. The results of these analyses have allowed us to identify the region of the viral genome coding for the V3 protein. In this report we describe the total nucleotide sequence of the genome region coding for the WN virus V3 protein and the amino acid sequence of the V3 protein derived from these analyses. The exact carboxy terminus of the V3 protein has not been determined in these experiments. These analyses have shown that the V3 protein of WN virus does not contain an Asn-X-Ser/Thr sequence which could allow addition of N-linked carbohydrate chains to this protein. In accordance with this finding, analyses of metabolic labeling of the V3 protein using [3H]glucosamine indicate that the WN virus V3 protein is an unglycosylated protein. Together with our earlier analyses these results show that the viral structural proteins are present on the genome RNA in the order 5'-terminus-core protein (V2)-small membrane-associated protein (NV2)-large membrane-associated protein (V3) and describe the nucleotide sequences coding for all WN virus structural proteins identified so far. A hypothesis concerning the processes involved in the synthesis of all viral structural proteins and the probable orientation of these proteins relative to the endoplasmatic reticulum membrane based on the structure of these proteins is discussed.

Akov, Y; Lustig, S; Halevy, M; Shapira, A. Phenotypic changes in West Nile virus propagated in mosquito cells. Israel Journal of Medical Sciences. 1984; 20 (5): 480. ISSN: 0021-2180. Annual Meeting of the Israel Society of Microbiology, Beersheva, Israel, Dec. 4-5, 1983.

Keywords: insect cell cultures, mosquito cells, viral changes due to cycles in cell culture.

Hayes, C.G.; R. Baker; S. Baqar; T. Ahmed. Genetic variation for West Nile virus susceptibility in Culex tritaeniorhynchus. American Journal of Tropical Medicine and Hygiene. July 1984. v. 33 (4) p. 715-724. ISSN: 0002-9637.

Descriptors: Culex tritaeniorhynchus, mosquito, disease vectors, viruses, susceptibility, genetic variation, strain differences, artificial selection.

Brinton, MA. Analysis of extracellular West Nile virus particles produced by cell cultures from genetically resistant and susceptible mice indicates enhanced amplification of defective interfering particles by resistant cultures. Journal of Virology. 1983 Jun; 46(3): 860-70. ISSN: 0022-538X.

Descriptors: viral particles from cell cultures, genetically resistant C3H/RV mice, congenic susceptible C3H/HE mice, compared, viral replication, genetically controlled resistance.

Abstract: [3H]uridine-labeled extracellular West Nile virus (WNV) particles produced by cell cultures obtained from genetically resistant C3H/RV and congenic susceptible C3H/HE mice were compared by sucrose density gradient centrifugation as well as by analysis of the particle RNA. Defective interfering (DI) WNV particles were observed among progeny produced during acute infections in both C3H/RV and C3H/HE cells. Although only a partial separation of standard and DI particles was achieved, the DI particles were found to be more dense than the standard virions. Particles containing several species of small RNAs consistently constituted a major proportion of the total population of virus progeny produced by C3H/RV cells, but a minor proportion of the population produced by C3H/HE cells. Decreasing the multiplicity of infection or extensive plaque purification of the WNV inoculum decreased the proportion of small RNAs found in the progeny virus. The ratio of DI particles to standard virus observed in progeny virus was determined by the cell type used to grow the virus. The ratio could be shifted by passaging virus from one cell type to the other. Homologous interference could be demonstrated with WNV produced by C3H/RV cells but not with virus produced by C3H/HE cells. Continued passage of WNV in C3H/HE cells resulted in a cycling of infectivity. However, passage in C3H/RV cells resulted in the complete loss of infectious virus. Four size classes of small viral RNA, with sedimentation coefficients of about 8, 15, 26, and 34S, were observed in the extracellular particles. A preliminary analysis of these RNAs by oligonucleotide fingerprinting indicated that the smaller RNAs were less complex than the 40S RNA and differed from each other. The data are consistent with the conclusion that WNV DI particles interfere more effectively with standard virus replication and are amplified more efficiently in C3H/RV cells than in congenic C3H/HE cells. The relevance of these findings to the further understanding of genetically controlled resistance to flaviviruses is discussed.

Brinton, MA; Fernandez, AV. A replication-efficient mutant of West Nile virus is insensitive to DI particle interference. Virology. 1983 Aug; 129(1): 107-15. ISSN: 0042-6822.

Descriptors: mutant WNV, c3H/RV mouse cell cultures, replication-efficient mutant, insensitive to interference by defective interfering particles, two areas of differences in the genome as compared to the parental strain, viral reproduction.

Abstract: A previous report described the isolation of a mutant of West Nile virus (WNV) from culture fluid obtained from persistently infected genetically resistant C3H/RV mouse cells that replicates significantly more efficiently in cultures of C3H/RV cells than does the parental virus. This replication-efficient mutant, designated RE-WNV, has now been found to be insensitive to interference by WNV defective interfering (DI) particles. This characteristic was demonstrated by several means. The RE-WNV mutant was able to superinfect persistently infected cultures that were no longer producing detectable parental virus, while the parental virus was not. Good yields of the mutant virus were produced during six serial undiluted passages of RE-WNV in both resistant C3H/RV and congenic susceptible C3H/HE cells. In contrast, during passage of parental virus in C3H/RV cells, progeny virus could not be detected after the third passage, due to an enhanced interference by WNV DI particles with standard virus replication in these cells. The RE-WNV was also insensitive to interference by a pool of parental virus enriched for DI particles. Analysis of the mutant genome by oligonucleotide fingerprinting indicated that the genome RNA of the mutant differs by two unique spots from the parental RNA. The relevance of this mutant to the eventual understanding of the mechanism by which C3H/RV and C3H/HE cells manifest their flavivirus-specific difference in the efficiency of progeny virus production is discussed.

Pogodina, VV; Frolova, MP; Malenko, GV; Fokina, GI; Koreshkova, GV; Kiseleva, LL; Bochkova, NG; Ralph, NM. Study on West Nile virus persistence in monkeys. Archives of Virology. 1983; 75(1-2): 71-86. ISSN: 0304-8608.

Descriptors: rhesus macques, various isolates, varying virulence, progress of the disease, viral resistance, sub-acute diseases of the central nervous system.

Abstract: Experiments in M. rhesus showed persistence to be a typical property of West Nile virus. This property was exhibited by strains belonging to different antigenic types, and varying in virulence and in the isolation area (U.S.S.R., Uganda, India). The duration of persistence was at least 5 1/2 months in asymptomatic infection and in convalescence after encephalitis or a febrile disease. The virus isolated within the first 2 weeks after inoculation of monkeys has the standard properties. The virus persisting for 2 months retains its cytopathic and antigenic activity, however, is non-pathogenic for white mice. After 5 1/2 months of persistence the virus has no neurovirulence or cytopathic properties but is capable of infecting the susceptible cells and induces in them the synthesis of virus-specific antigen detectable by immunofluorescence. The persisting virus has been isolated by cocultivation of trypsinized monkey organ cells and cells of the indicator culture. This virus was located mostly in the cerebellum, cerebral subcortical ganglia, lymph nodes, and kidneys. The monkeys experiencing encephalitis, febrile, or asymptomatic infection showed in morphological examinations a subacute inflammatory-degenerative process in the central nervous system. The results suggest that West Nile virus, one of the most widely spread arboviruses in Africa, Asia, and Europe, may be implicated in the etiology of subacute diseases of the CNS.

Akhter, R; Hayes, CG; Baqar, S; Reisen, WK. West Nile virus in Pakistan. III. Comparative vector capability of Culex tritaeniorhynchus and eight other species of mosquitoes. Transactions of the Royal Society of Tropical Medicine and Hygiene. 1982; 76(4): 449-53. ISSN: 0035-9203.

Descriptors: experimental mosquito vectors, experimental feeding of WNV in defibrinated blood, Culex tritaeniorhynchus, Cx fuscocephala and Cx pseudovishnui, Culex quinquefasciatus, Culex univittatus, Aedes albopictus, Aedes caspius, Aedes indicus, Aedes lineatopennis, feeding on viremic chickens, intrathoracic inoculationm ability to transmit disease, Pakistan.

Abstract: Eight species of mosquitoes from Pakistan were compared with Culex tritaeniorhynchus as experimental vectors of West Nile (WN) virus. When fed by the membrane or cotton-pledget methods on a dose of WN virus 100% infective for Cx tritaeniorhynchus, 95% and 73% of the females of Cx fuscocephala and Cx pseudovishnui became infected, respectively. Cx quinquefasciatus, Cx univittatus, Aedes albopictus, Ae. caspius, Ae. indicus and Ae. lineatopennis were all significantly less susceptible than Cx tritaeniorhynchus. In agreement with the single dose comparisons, the median per os infective dose of WN virus for Cx fuscocephala, Cx pseudovishnui and Ae. caspius was substantially greater than for Cx tritaeniorhynchus. The median parenteral infective dose for all six species tested was less than 1 SMICLD50. Both Cx tritaeniorhynchus and Cx quinquefasciatus were more susceptible to infection with WN virus when fed on viraemic chickens than when fed on defibrinated blood using cotton pledgets or membranes. After infection by intrathoracic inoculation, only Ae. indicus and Ae. lineatopennis showed a reduced ability to transmit WN virus when compared to Cx tritaeniorhynchus.

Brinton, MA. Characterization of West Nile virus persistent infections in genetically resistant and susceptible mouse cells. I. Generation of defective nonplaquing virus particles. Virology. 1982 Jan 15; 116(1): 84-98. ISSN: 0042-6822.

Descriptors: mouse cell cultures, virus physiology, viral reproduction and persistence, SV 40 transformed mouse embryo fibroblast cells, hamster kidned BHK cells, dense cytoplasmic vacuoles, RNA

George, TD St; St George, TD; Kay, BH; McIntosh, BM; Jupp, PG; St George, TD (ed.); Kay, BH (ed.). Ecological studies on West Nile virus in southern Africa. Arbovirus Research in Australia. Proceedings 3rd symposium. 15-17 February 1982. 1982?, 82-85; 13 ref.

Descriptors: disease distribution, insect vectors, Culex univittatus, humans, birds.

Hayes, CG; Baqar, S; Ahmed, T; Chowdhry, MA; Reisen, WK. West Nile virus in Pakistan. 1. Sero-epidemiological studies in Punjab Province. Transactions of the Royal Society of Tropical Medicine and Hygiene. 1982; 76(4): 431-6. ISSN: 0035-9203.

Descriptors: epidemiology, sera surveys, humans, birds, a cow, other animals, antibody titers, Dengue, Pakistan I-746 strain of West Nile virus.

Abstract: Serum samples collected during 1978-79 from residents of the Chiniot and Changa Manga National Forest (CMF) areas of Punjab Province, Pakistan, had over-all neutralizing (N) antibody positive rates for West Nile (WN) virus of 32.8% (n = 192) and 38.5% (n = 239), respectively. Comparison of the age-specific antibody rates indicated that the pattern of exposure to infection was different in the two areas. Samples from a 1968 serosurvey of residents of the CMF area had an age-specific N antibody profile similar to the 1978 CMF sample, but both the over-all N and haemagglutination-inhibition (HI) antibody positive rates were much higher in the 1968 sample. When tested against antigen prepared from the Pakistan I-746 strain of WN virus, the percentage of sera HI antibody positive and the geometric mean titre of the sera were significantly higher than when tested against the Egypt-101 antigen. One of 124 and 11 of 50 sera from the 1978 and 1968 samples from CMF exhibited detectable HI antibody against dengue-3 virus, respectively, indicating cross-reacting flavivirus antibody was present. None of the positive sera had a higher titre against dengue-3 than against WN virus, but four of the 1968 sera reacted to equal titre against both antigens. During the 1978-79 CMF survey, serum samples from domestic and wild animals were tested for WN virus antibody. Of the 317 wild birds captured, 85 were N-antibody positive. The only frequently bled mammal was the Indian cow, from which 21 of 58 samples were positive for WN antibody.

Kislenko, GS; Chunikhin, SP; Rasnitsyn, SP; Kurenkov, VB; Izotov, VK. Study of Powassan and West-Nile virus reproduction in Aedes-aegypti mosquitoes and in their cell culture. Meditsinskaya Parazitologiya i Parazitarnye Bolezni. 1982; 51 (3): 13-15. ISSN: 0025-8326. In Russian.

Descriptors: viral reproduction, physiology, pathology, tissue culture of mosquito cells.

Reisen, WK; Hayes, CG; Azra, K; Niaz, S; Mahmood, F; Parveen, T; Boreham, PFL. West Nile virus in Pakistan. II. Entomological studies at Changa Manga National Forest, Punjab Province. Transactions of the Royal Society of Tropical Medicine and Hygiene. 1982, 76: 4, 437-448; 6 fig.; 43 ref. ISSN: 0035-9203.

Descriptors: infectivity, mosquito resting places, seasonal abundance cycles, rrigation water, prevention, Culex tritaeniorhynchus, Culex quinquefasciatus, Aedes lineatopennis, Aedes w albus, Aedes caspius, Culex fuscocephalus, Culex pseudovishnui, Mansonia uniformis, cattle, humans, Anopheles, Aedes yusafi, Aedes-indicus, Aedes culicinus.

Vinograd, IA; Beletskaia, GV; Chumachenko, SS; Ardamatskaia, TB; Rogochii, EG. Vydelenie virusa Zapadnogo Nila na iuge Ukrainskoi SSR. [Isolation of West Nile virus in the Southern Ukraine]. Voprosy Virusologii. 1982 Sep-Oct; 27(5): 55-7. ISSN: 0507-4088. In Russian.

Descriptors: internal organs, birds, rook, virus isolation, pathogenic to mice, intro-cerebral injection, chick embryo culture, chick embryo fibroblast cultures, L cells, swine embryo kidney cells, pathogenecity, Ukrainian strain.

Abstract: A virus (strain No. 3266) was isolated from the blood and internal organs of a rook caught in May, 1980, in the territory of the Black Sea State Preserve of the Ukrainian Academy of Sciences (the Kherson region). The virus is pathogenic for 1--2-day-old mice by various routes of inoculation and for 3-week-old mice by the intracerebral route; it multiplies in chick embryos, in chick embryo fibroblast cultures without the cytopathic effect, and in continuous L cells and pig embryo kidney cells with definite cytopathic effect. The virus contains RNA and has a lipid-containing membrane; according to the results of filtration through Millipore filters, its size ranges from 50 to 100 nm. From the results of immunofluorescent studies and serological identification this strain has been classified as West Nile virus. The characteristics of the biological properties of this virus isolated in the Ukraine have first been described.

Akhtar, R.; C. Hayes; S. Baqar. Dual infections of Culex tritaeniorhynchus with West Nile virus and Nosema algerae. Journal of Parasitology. Aug 1981. v. 67 (4) p. 571-573. ISSN: 0022-3395. Bibliography p. 573.

Descriptors: Culex tritaeniorhynchus, mosquito, West Nile virus, Nosema algerae, feeding technique, replication, susceptibility, disease vector, pathogenic parasite, biological control.

Brinton, MA. Isolation of a replication-efficient mutant of West Nile virus from a persistently infected genetically resistant mouse cell culture. Journal of Virology. 1981 Aug; 39(2): 413-21. ISSN: 0022-538X.

Descriptors: mouse embryo fibroblasts C4H/RV, WNV strain E101, viral levels in cell culture, viral proteins, regulation of transcription of flavivirus RNA.

Abstract: Flavivirus-resistant mouse embryofibroblasts (C3H/RV) that were infected with West Nile virus, strain E101 (WNV), yielded fewer infectious virions than did cultures of congenic susceptible cells (C3H/HE). Analysis of intracellular viral RNA synthesis indicated that the incorporation of [3H]uridine into 40S genome RNA was markedly reduced in resistant cells, and about 100-fold less labeled 40S RNA was found in pelleted extracellular virions from resistant cultures than in those from susceptible ones. A non-temperature-sensitive mutant of WNV isolated from culture fluid of a persistently infected culture of genetically resistant mouse cells was found to produce higher yields of infectious virus than the parental WNV used to initiate the persistent infection. Analysis of intracellular actinomycin D-resistant RNA indicated that the mutant virus (WNV-RV) was more efficient at incorporating [3H]uridine into 40S RNA in resistant cells than was the parental virus. WNV-RV also synthesized 40S RNA more efficiently than parental virus in congenic susceptible cells and in BHK cells. Analysis of the incorporation of [35S]methionine into viral proteins was likewise enhanced in WNV-RV-infected cells. The WNV-RV mutant provides a tool for studying the regulation of transcription of flavivirus RNA.

Baqar, S.; C. Hayes; T. Ahmed. The effect of larval rearing conditions and adult age on the susceptibility of Culex tritaeniorhynchus to infection with West Nile virus. Mosquito News. June 1980. v. 40 (2) p. 165-171. ISSN: 0027-142X.

Descriptors: Culex tritaeniorhynchus, mosquito, West Nile virus, environmental factors, age factor, pupation, stress indicators, feeding technique, susceptibility, biological control.

Deshmane, SL; Banerjee, K. Poly peptides of Japanese encephalitis virus and West-Nile virus. Indian Journal of Medical Research. 1980; 71 (FEB): 157-163. ISSN: 0019-5340.

Descriptors: electrophoreses, study of peptides and amino acids, virology methods.

Hayes, C.G.; A. Basit; S. Bagar; R. Akhter. Vector competence of Culex tritaeniorhynchus (Diptera: Culicidae) for West Nile virus. Journal of Medical Entomology. Mar 31, 1980. v. 17 (2) p. 172-177. ill. ISSN: 0022-2585.

Descriptors: Culex tritaeniorhynchus, mosquito, West Nile virus, disease vector, vector competence, inoculation, replication, transmission, feeding technique, susceptibility, Egypt.

Izotov, VK; Chunikhin, SP. Comparative characteristcs of Getah and West-Nile virus reproduction in cell cultures of mosquitoes of 3 species. Meditsinskaya Parazitologiya i Parazitarnye Bolezni. 1980; 49 (4): 34-37. ISSN: 0025-8326. In Russian

Descriptors: comparative reproduction, mosquito cell cultures, Aedes albopictus, Aedes pseudoscutellaris, Aedes aegypti, Hanks’ medium plus 10% calf serum, C-45 solution, virus reproduction.

Oaten, SW; Webb, HE; Jagelman, S. Resistance of mice to infection with West Nile virus following pre treatment with Sindbis Semliki-Forest and Chikungunya virus. Microbios Letters. 1980; 13 (50): 85-90. ISSN: 0307-5494.

Descriptors: mouse model, intra-cutaneous injection, virology, effects of multiple infections.

Ahmed, T.; C. Hayes; S. Baqar. Comparison of vector competence for West Nile virus of colonized populations of Culex tritaeniorhynchus from southern Asia and the far east. Southeast Asian Journal of Tropical Medicine and Public Health. Dec 1979. v. 10 (4) p. 498-504. ill. ISSN: 0038-3619. Bibliography p. 502-504.

Descriptors: Culex tritaeniorhynchus, mosquito, West Nile virus, disease vector, transmission, feeding technique, susceptibility, juvenile mice, inoculation, biological control, far east, Asia.

Wengler, G; Beato, M; Wengler, G. In vitro translation of 42 S virus-specific RNA from cells infected with the flavivirus West Nile virus. Virology. 1979 Jul 30; 96(2): 516-29. ISSN:0042-6822.

Descriptors: arboviruses metabolism viral RNA, translation genetics, biosysthesis of viral proteins, hamster kidney cell line, methionine metabolism, peptides fragment analysis.

Eylar, O.R.; C. Wisseman. An unusually high divalent cation requirement for attachment of West Nile virus to primary chick embryo cells. Proceedings of the Society for Experimental Biology and Medicine. Feb 1978, 157 (2): 322-325. Ref.

Descriptors: West Nile virus, cell culture, cell adsorption, plaque assay, viral attachment, experimental infection, divalent cations, chick embryo cells.

Gaidamovich, SY; Ismailov, AS; Klisenko, GA; Mirzoeva, NM. Detection of Sindbis virus and West-Nile virus in the blood of living birds by indirect hemagglutination. Acta Virologica. 1978; 22 (5): 430. ISSN: 0001-723X.

Descriptors: birds, sheep erythrocyte viremis, Ardeola ralloides, Bubulcus ibis, Nycticoras nycticoras, Larus argentatus.

Lavrova, NA. Dinamika nakopleniia infektsionnogo virusa Zapadnogo Nila, virusnykh antigenov pri eksperimental'noi infektsii myshei. [Dynamics of accumulation of infectious West Nile virus and viral antigens in experimental infection of mice]. Voprosy Virusologii. 1977 Mar-Apr; (2): 193-6. ISSN: 0507-4088. In Russian.

Descriptors: mouse model, experimental model, antigens, infectious virus, blood and brain sampling, virus titers, soluble antigens levels.

Abstract: The appearance of the hemagglutinating (HA), complement-fixing (CF) and soluble (S) antigens and infectious virus in the blood and brain of suckling mice inoculated with various doses of West Nile virus was studied. The infectious virus was isolated from the blood and brains of mice as early as 24 hours after inoculation. Its titres increased in parallel in the brain and blood reaching maximum levels by the end of infection. The HA antigen was detected only in the brain at 2-3 days after inoculation. The CF antigen was detected in the blood in a low titre only in the terminal stage of infection; in the brain the CF antigen was detected within 24 hours after infection with a low dose and within 48 hours with a high dose. The S antigen was isolated only from the brain tissue, and in higher titres after infection with a large dose. This may be associated with excess synthesis of the S antigen at a high multiplicity of infection.

Odelola, HA; Fabiyi, A. Biological characteristic of Nigerian strains of West Nile virus in mice and cell cultures. Acta Virologica. 1977 Mar; 21(2): 161-4. ISSN: 0001-723X.

Descriptors: 7 Nigerian isolates, experimental infections in mice, virus levels in cell cultures, organ sampling, viral biology and physiology.

Abstract: The biological characteristic in mice and cell cultures of 7 strains of West Nile (WN) virus isolated in Nigeria were studied. The pattern of virus development in most organs of mice infected with two of the seven strains tested was identical, while it varied with the remaining five strains. All 7 strains of WN virus multiplied with a cytopathic effect (CPE) in the four cell cultures examined.

Odelola, H.A.; O. Oduye. West Nile virus infection of adult mice by oral route. Archives of Virology. 1977, 54 (3): 251-253. Ref.

Descriptors: West Nile virus, experimental infection, Swiss albino mice, antibodies, histology, transmission, feeding technique, Nigeria.

Umrigar, MD; Pavri, KM. Comparative biological studies on Indian strains of West Nile virus isolated from different sources. Indian Journal of Medical Research. 1977 May; 65(5): 596-602. ISSN: 0971-5916.

Descriptors: pathogenicity, cell lines, cytopathogenic effects, LD 50, plaque assay, India.

Umrigar, MD; Pavri, KM. Comparative serological studies on Indian strains of West Nile virus isolated from different sources. Indian Journal of Medical Research. 1977 May; 65(5): 603-12. ISSN: 0971-5916.

Descriptors: viral antigen analysis, epitopes, immunology, cross reactions, Indian strains.

Jupp, PG. The susceptibility of 4 South African species of Culex to West-Nile virus and Sindbis virus by 2 different infecting methods. Mosquito News. 1976; 36 (2): 166-173. ISSN: 0027-142X.

Descriptors: pigeons, birds, chickens, Culex pipiens, Culex quinquefasciatus, Culex fatigans, Cules univittatus, Culex theirleri, insect disease vectors.

Labuda, M; Kozuch, O; Gresikova, M. Relationship of West-Nile virus to mosquitoes under central European conditions. Folia Microbiologica. 1976; 21 (3): 248. ISSN: 0015-5632.

Descriptors: Aides, contans, Aedes communis, Aedes punctar, Aedes cataphylla, Aedes sticticus, Aedes annulipis, Aedes cinereus, Aedes vexans, Mansonia richiardii, pathogenicity, effects of climate.

Lengle, E.E.; F. Frerman; S. Grossberg. Alterations in the developmental patterns of enzymes in chicken embryos infected with West Nile virus. Archives of Biochemistry and Biophysics. Nov 1, 1976, 177 (1): 157-169. Ref.

Descriptors: West Nile virus, experimental infection, embryonic development, enzymes, metabolites, pathway, lipids, liver, Group B Togavirididae, chicken embryos.

Odelola, HA; Fabiyi, A. Antigenic relationships among Nigerian strains of West Nile virus by complement fixation and agar gel precipitation techniques. Transactions of the Royal Society of Tropical Medicine and Hygiene. 1976; 70(2): 138-44. ISSN: 0035-9203.

Descriptors: Nigerian isolates, antigenic relationships between local and world strains, 2 intra-typic groups.

Abstract: Using two serological techniques, eight Nigerian West Nile virus isolates were investigated to determine antigenic relationships among them, and to find out if these virus isolates were related to West Nile virus strains from the different zoogeographic areas of the world. One virus differed significantly from the seven other strains and was later found to be a strain of Usutu virus. The remaining strains were differentiated into two serological intratypic groups depending on their cross reactions with two strains which served as prototypes for each group. Five virus isolates which constitute one of the antigenic groups were found to be related to the Egypt 101 strain of West Nile virus originating from general Palearctic zone (European and Middle East). The other two virus isolates did not show any relationship to the strains from any of the different zoogeographic zones.

Sekeyova, M; Gresikova, M; Batikova, M. Serological surveys showing West-Nile virus in some parts of central Europe. Folia Microbiologica. 1976; 21 (3): 249. ISSN: 0015-5632.

Descriptors: epidemiology, insects disease vectors, aquatic birds, cattle, dogs, humans, Aedes cantans, Czechoslovakia, Austria.

Ajello, C.; M. Gresikova; S. Buckley; J. Casals. Detection of West Nile [virus] complement-fixing antigen in Aedes albopictus cell cultures. Acta Virologica. Sept 1975, 19 (5): 441-442.

Descriptors: Aedes albopictus, mosquito, West Nile virus, cell culture, antigen, encephalitis, antisera, ticks, plaque assays, detection.

Harley, EH; Losman, MJ; Hall, E; Naude, WDT. The RNA forms of West-Nile virus with some comparative studies on Sindbis virus. South African Journal of Science. 1975; 71 (10): 305-308. ISSN: 0038-2353.

Descriptors: HeLa cells, comparative studies, genetics, cytology genetics, reproduction.

Harley, EH; Losman, MJ; Hall, E; Naude, WDT. The RNA forms of West-Nile virus with some comparative studies on Sindbis virus. South African Journal of Science. 1975; 71 (10): 305-308. ISSN: 0038-2353.

Johnson, B.K.; M. Varma. Infection of the mosquito Aedes aegypti with infectious West Nile virus-antibody complexes. Transactions of the Royal Society of Tropical Medicine and Hygiene. 1975, 69 (3): 336-341. Ref.

Descriptors: Aedes aegypti, mosquito, West Nile virus, antibody, experimental infection, yellow fever virus, susceptibility, dengue virus, antisera, plaque assay, feeding technique.

Lengle, EE; Grossberg, SE. Development of a hyper lipidemia in chicken embryos infected with West-Nile virus. Federation Proceedings. 1975; 34 (3): 673. ISSN: 0014-9446.

Descriptors: cell culture procedure, chick embryos, effects of infection, biochemistry of infection.

Odelola, HA; Koza, J. Characterization of Nigerian strains of West-Nile virus by plaque formation. Acta Virologica. 1975; 19 (6): 489-492. ISSN: 0001-723X

Descriptors: monkey kidney cell culture plates, antigenic relatedness, intro-typic groups, strain genetics, virus plaques causing potential tested, intratypic group, 5 strains tested.

Abstract: Seven strains of West nile virus isolated in Nigeria were investigated for their ability to form plaques in monkey kidney cell monolayers. Five strains antigenically related to one another produced plaques of about the same size 3 to 4 days after the addition of the overlay medium. The two other strains closely related to each other produced no plaques. Their inability to produce plaques was regarded as a significant characteristic of the intratypic group to which the two strains belong.

Gaidamovich, S IA; Lavrova, NA. Izuchenie razlichnykh antigenov virusa Zapadnogo Nila. [Study of West Nile virus antigens]. Voprosy Virusologii. 1974 Nov-Dec; (6): 692-6. ISSN: 0507-4088. In Russian.

Descriptors: infected mouse brain tissue, centrifugation, soluable antigens, other antigens, African and Indian strains, complement fixation.

Joubert, L.; J. Oudar. West Nile meningoencephalitis virus of the horse in the Mediterranean south of France.

Bulletin de la Societe des sciences veterinaires et de medecine comparee de Lyon. 1974, 76 (4): 255-260. Ref. In French.

Descriptors: West Nile virus, horse, meningoencephalitis, Mediterranean, south of France.

Jupp, P.G. Laboratory studies on the transmission of West Nile virus by Culex (Culex) univittatus Theobald; factors influencing the transmission rate. Journal of Medical Entomology. Aug 1974, 11 (4): 455-458. Ref.

Descriptors: Culex univittatus, mosquito, West Nile virus, experimental infection, feeding technique, transmission rate, temperature and other environmental factors.

Labuda, M.; O. Kozuch; M. Gresikova. Isolation of West Nile virus from Aedes cantans mosquitoes in west Slovakia. Acta Virologica, Sept 1974, 18 (5): 429-433. Ref.

Descriptors: Aedes cantans, mosquito, West Nile virus, cell culture, experimental infection, isolation technique, cytopathic effect, inhibition test, neutralization test, complement fixation test, sensitivity, Malacky, western Slovakia, central Europe.

Lengle, EE; Grossberg, SE; Frerman, FE. Control of hepatic lipid biosynthesis in chicken embryos infected with West Nile virus. Federation Proceedings. 1974; 33 (5 PART 2): 1543. ISSN: 0014-9446

Descriptors: liver lipids, cell cultures, chick embryos, biochemical effects of viral infection of embryos.

Naude, WDT; Stannard, LM. Buoyant density of the RNA of West-Nile virus. South African Journal of Laboratory and Clinical Medicine. 1974; 20 (2): 1218. ISSN: 0038-2299.

Filipe, AR; Sobral, M; Campanico, FC. Encefalomielite equina por arbovirus. A proposito de uma epizootia presuntiva causada pelo virus West Nile. [Equine encephalomyelitis caused by arbovirus. On an epizootic attributed to West Nile virus]. Revista Portuguesa de Ciencias Veterinarias. 1973, 68: 426, 90-101; 1 fig.; 19 ref. In Portuguese with English and French summaries.

Descriptors: horse deaths, epidemiology, southern Portugal, antibody survey, Anopheles maculipennis as insect disease vector, Anopheles coustani.

Gaidamovich, S YA; Lavrova, NA. Soluble antigen of West Nile virus. Acta Virologica. 1973; 17 (6): 513. ISSN: 0001-723X.

Descriptors: ascetic fluid immunology, complement fixation tests, epitopes, hemagglutination tests, sera, mice, genetic variation, mouse brain tissue, antigens, infected brain tissue.

Gaidamovich, SY; Sokhey, J. Studies on antigenic peculiarities of West Nile virus strains isolated in the U.S.S.R. by three serological tests. Acta Virologica. 1973 Jul; 17(4): 343-50. ISSN: 0001-723X.

Descriptors: antigens, immunology, ascetic fluids, complement fixation tests, cross reactions, hemagglutination inhibition tests, mice, immunodiffusion, sera, isolation and purification of virus.

Joubert, L.; P. Tuaillon; M. Prave; F. Chabrouty. Culture of West Nile virus on an Aedes albopictus mosquito cell line: Persistent cellular infection without cytopathogenic action. [Culex modestus, insect vectors]. Bulletin de la Societe des Sciences Veterinaires et de Medecine Comparee de Lyon. 1973, 74 (5): 373-379. Ref. In French.

Descriptors: Aedes albopictus, Culex modestus, mosquito, West Nile virus, cell culture, cellular infection, experimental infection, insect vector.

Kemp, GE; Causey, OR; Moore, DL; O'Connor, EH. Viral isolates from livestock in northern Nigeria: 1966-1970. American Journal of Veterinary Research. 1973, 34: No.5, 707-710. ISSN: 0002-9645.

Descriptors: blood sampling survey, cattle, sheep, goats, camels, pre-slaughter, introcerebral inoclulation of mice, 33 viral isolates, 10 viral types including West Nile and other arboviruses, Nigeria.

Semenov, BF; Chunikhin, SP; Karmysheva, V YA; Yakovleva, NI. Study of chronic forms of arbovirus infections in birds. Part I. Experiments with Sindbis virus, West-Nile virus and Bhandja virus and Sicilian mosquito fever virus. Vestnik Akademii Meditsinskikh Nauk SSSR. 1973; 28 (2): 79-83. ISSN: 0002-3027.

Sidorova, GA; Gromashevskii, VL; Veselovskaya, OV; Neronov, VM; Rustamov, BR; Musatova, AI; Ipatov, VP; L'-vov, DK (ed.). Isolation of West Nile virus from Ixodid and Argasid ticks collected in the arid regions of Uzbekistan. Ekologiya Virusov Sbornik Trudov. Vypusk I. 1973, 87-90; 11 ref. In Russian.

Descriptors: Hyalomma asiaticum ticks, insect vector, disease reservoir, epidemiological implications.

Filipe, A.R. Isolation in Portugal of West Nile virus from Anopheles maculipennis mosquitoes. Acta Virologica. July 1972, 16 (4): 361.

Descriptors: Anopheles maculipennis, mosquito, West Nile virus, antigenicity, experimental infection, mice, inhibition test, characteristics, sera, antibodies, southern Portugal.

Joubert, L; Tuaillon, P; Prave, M; Chabrouty, F. Culture du virus West Nile sur une lignee cellulaire de moustique 'Aedes albopictus'. Infection cellulaire persistante sans action cytopathogene. [Culture of West Nile virus in the cell-line of the mosquito 'Aedes albopictus'. Persistent cellular infection without cytopathogenic action]. Bulletin de la Societe des Sciences Veterinaires et de Medecine Comparee de Lyon. 1972, 74: 5, 373-378; 4 fig.; 28 ref. In French.

Descriptors: mosquito cell line, Aedes albopictus, viral infection, cytopathogenic action.

Oudar, J; Joubert, L; Lapras, M; Hannoun, C; Guillon, JC. Reproduction experimentale de la meningo-encephalomyelite animale par l'arbovirus West-Nile. IV. Recherche des reservoirs de virus. Inoculation au mouton et au porc. [Experimental reproduction of animal meningo-encephalomyelitis by West Nile arbovirus. IV. Investigation of reservoirs of the virus. Inoculation into sheep and pigs]. Bulletin de l'Academie Veterinaire de France. 1972, 45: No.4, 195-206. ISSN: 0001-4192. In French.

Price, WH; Thind, IS. The mechanism of cross-protection afforded by dengue virus against West Nile virus in hamsters. Journal of Hygiene. 1972 Dec; 70(4): 611-7. ISSN: 0022-1724.

Descriptors: immunology, effects of double infection, experimental infection, arboviruses, immune effects, hamsters.

Semenov, BF; Vargin, VV. Izmenenie svoistv antitel v protsesse immunnogo otveta krolikov na vvedenie virusa Zapadnogo Nila. Kharakteristika gomo- i geterologicheskoi aktivnosti immunoglobulinov v reaktsii podavleniia gemaggliutinatsii. [Change in antibody properties in the course of the immune response in rabbits to West Nile virus inoculation. Characteristics of the homo- and heterologous activity of immunoglobulins in the hemagglutination inhibition reaction]. Voprosy Virusologii. 1972 Sep-Oct; 17(5): 540-4. ISSN: 0507-4088. In Russian.

Descriptors: experimental infection, rabbits, immune response, antibody variation as the disease progresses, immunoglobulins, hemagglutination inhibition test.

Semenov, BF; Vargin, VV. Izmenenie svoistv antitel pri pervichnom immunnom otvete krolikov na vvedenie virusa Zapadnogo Nila. I. Kharakteristika virusneitralizuiushchikh antitel. Sootnoshenie spetsificheskikh i nespetsificheskikh faktorov immuniteta. [Change in the properties of antibodies in the primary immune response of rabbits to inoculation with West Nile virus. I. Characteristics of virus-neutralizing antibodies. Correlation between specific and non-specific factors of immunity]. Voprosy Virusologii. 1972 Mar-Apr; 17(2): 138-43. ISSN: 0507-4088. In Russian.

Descriptors: experimental infection, rabbits, primary immune response, antibody variation as the disease progresses, immunoglobulins, characteristics of virus-neutralizing antibodies.

Aleshin, LP; Gaidamovich, S Ia; Nikiforov, LP; Chervonskii, VI; Gromashevskii, VL. Uchastie ptits vodno-okolovodnogo kompleksa iugo-vostochnogo Azerbaidzhana v tsirkuliatsii virusa Zapadnogo Nila. [Participation of birds in the water-nearwater complex of southeastern Azerbaijan in the circulation of the West Nile virus]. Voprosy Virusologii. 1971 Mar-Apr; 16(2): 211-5. ISSN: 0507-4088. In Russian.

Descriptors: birds as disease reservoirs, insect vectors, disease transmission and spread, Russia.

Darwish, MA; Ibrahim, AH. Survey for antibodies to arboviruses in Egyptian sera. I. West Nile virus antihemagglutinins in human and animal sera. Journal of the Egyptian Public Health Association. 1971; 46(2): 61-70. ISSN: 0013-2446.

Descriptors: birds, Dengue virus, immunology, Egypt, encephalitis viruses, hemagglutination inhibition tests.

Gallifet, P. Contribution a l'etude des zoonoses arbovirales. Essai de reproduction experimentale de l'encephalomyelite West-Nile chez le mouton et chez le porc. [Arboviral zoonoses. Attempt to induce West Nile encephalomyelitis in sheep and pigs]. 1971, 62 pp. Thesis. Ecole Nationale Veterinaire de Lyon. In French.

Descriptors: experimental infection of sheep and swine, results of infection, immunology.

Haahr, S. The influence of Poly I:C on the course of infection in mice inoculated with West Nile virus. Archiv fur die Gesamte Virusforschung. 1971; 35(1): 1-9. ISSN: 0003-9012.

Descriptors: antibodies analysis, encephalitis viruses, prevention and control, interferons, hemagglutination inhibition tests, mice, inbred strains of mice, polynucleotides, Semliki forest virus.

Joubert, L.; J. Oudar; C. Hannoun; M. Chippaux. Experimental reproduction of meningoencephalomyelitis in the horse with the West Nile virus. III. Relations between virology, serology and anatomical and clinical development: epidemiological and prophylactic consequences. Bulletin de l'Academie veterinaire de France. Mar 1971, 44 (3): 159-167. In French.

Descriptors: West Nile virus, menigoencephalomyelitis, horse, experimental reproduction, virology, serology, anatomical and clinical development, epidemiological and prophylactic consequences.

Oudar, J.; L. Joubert; C. Hannoun; B. Corniou. Experimental reproduction of meningoencephalomelitis in the horse with the West Nile virus. I. Virological and serological study. Bulletin de l'Academie veterinaire de France. Feb 1971, 44 (2): 107-122. Ref. In French.

Descriptors: West Nile virus, menigoencephalomyelitis, horse, experimental reproduction, virology, serology.

Oudar, J.; L. Joubert; M. Lapras; J. Guillon. Experimental reproduction of meningoencephalomyelitis in the horse with the West Nile virus. II. Anatomical and clinical study. Bulletin de l'Academie veterinaire de France. Mar 1971, 44 (3): 147-158. In French.

Descriptors: West Nile virus, menigoencephalomyelitis, horse, experimental reproduction, anatomical and clinical study.

Price, WH; Thind, IS. Protection against West Nile virus induced by a previous injection with dengue virus. American Journal of Epidemiology. 1971 Dec; 94(6): 596-607. ISSN: 0002-9262.

Descriptors: antibody formation, viral vaccine potential, cross reactions, viral interference, infection physiology, hamsters.

Work, T.H. On the Japanese B--West Nile virus complex or an arbovirus problem of six continents. American Journal of Tropical Medicine and Hygiene. Mar 1971, 20 (2): 169-186. map. Bibliography: p. 184-186.

Descriptors: West Nile virus, arbovirus, mosquitoes, epidemiology, virology, presidential address, India.

Bargin, VV; Semenov, BF. Use of the color test for titration of the antibody to West Nile virus in micro volumes of sera. Voprosy Virusologii. 1970; 15 (4): 500-502. ISSN: 0507-4088.

Chippaux-Hyppolite, C; Choux, R; Olmer, H; Tamalet, J. Multiplication du virus West-Nile dans les cultures cellulaires d'embryon de poulet, observee en microscopie electronique. [Multiplication of West Nile virus in cell cultures of chick embryo, observed by electron microscope]. Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences. Serie D Sciences Naturelles. 1970 Jun 22; 270(25): 3162-5. ISSN: 0567-655X. In French.

Descriptors: chick embryos cell culture, viral multiplication, electron microscopic images of changes after infection.

Gresset, M. Contribution a l'etude des zoonoses arbovirales. Reproduction experimentale de l'encephalomyelite a virus West-Nile du cheval. [Arbovirus zoonoses: experimental reproduction of West Nile encephalomyelitis in horses]. 1970, 78 pp. These. Ecole Nationale Veterinaire de Lyon. In French.

Haahr, S. The effect of anti lymphocyte serum on circulating interferon and viremia in mice infected with West Nile virus. Acta Pathologica et Microbiologica Scandinavica Supplementum. 1970; SEC (215): 15.

Descriptors: white cell anti-sera sera, experimental infection, mice, effects on immune response, viral concentrations, interferon.

Joubert, L; Oudar, J; Hannoun, C; Beytout, D; Corniou, B; Guillon, JC; Panthier, R. Epidemiologie du virus West Nile: etude d'un foyer en Camargue. IV. La meningo-encephalomyelite du cheval. [Epidemiology of the West Nile virus: study of a focus in Camargue. IV. Meningo-encephalomyelitis of the horse]. Annales de l'Institut Pasteur. 1970 Feb; 118(2): 239-47.ISSN: 0020-2444. In French.

Descriptors: horses, southern France, epidemiology of disease in horses, progress of the disease.

Joubert, L; Oudar, J.Arboviral zoonoses their presence in France. Part 2. West Nile virus horse meningo encephalo myelitis in the Mediterranean District of France. Revue de Medecine Veterinaire Toulouse. 1970; 121 (3): 221-246. ISSN: 0035-1555.

Descriptors: arboviruses, epidemiology, horses, encephalomyelitis, southern France.

Jupp, PG; McIntosh, BM. Quantitative experiments on the vector capability of Culex-culex-pipens-fatigans with West Nile virus and Sindbis virus. Journal of Medical Entomology. 1970; 7 (3): 353-356. ISSN: 0022-2585.

Jupp, PG; McIntosh, BM. Quantitative experiments on the vector capability of Culex-culex-univittatus with West Nile virus and Sindbis virus. Journal of Medical Entomology. 1970; 7 (3): 371-373. ISSN: 0022-2585.

Mouchet, J.; J. Rageau; C. Laumond; C. Hannoun; D. Beytout; J. Oudar; B. Corniou; A. Chippaux. Epidemiology of the West Nile virus: study of a focus in Camargue. Annales de l'Institut Pasteur. June 1970, 118 (6): 839-855. In French with English summary. Bibliography: p. 853-855.

Descriptors: Culex molestus, mosquitoes, insect vectors, epidemiology, Camargue (Rhone river delta).

Paul, SD; Rajagopalan, PK; Sreenivasan, MA. Isolation of the West Nile virus from the frugivorous bat, Rousettus leschenaulti. Indian Journal of Medical Research. 1970 Sep; 58(9): 1169-71. ISSN: 0971-5916.

Pilo-Moron, E; Vincent, J; Le-Corroller, Y. Isolement d'un virus West-Nile dans l'extreme sud du Sahara algerien (Djanet. [Isolation of a West-Nile virus in the extreme south of the Algerian Sahara (Djanet)]. Archives Institut Pasteur d'Algerie. 1970; 48: 181-4. ISSN: 0020-2460. In French.

Weiner, LP; Cole, GA; Nathanson, N. Experimental encephalitis following peripheral inoculation of West Nile virus in mice of different ages. Journal of Hygiene. 1970 Sep; 68(3): 435-46. ISSN: 0022-1724.

Descriptors: experimental infection, mouse model, viral disease, thigh injection, brain pathology, tickborne blood, immunology, fluorescent antibody techniques, hemagglutination inhibition tests, kidney and spleen sampling.

Duca, E; Buiuc, D; Bernescu, E; Morosanu, V. Efectul conditiilor de recoltare si conservare a serurilor pina in momentul testarii, asupra eficientei adsorbtiei cu caolin sau extractiei cu acetona in vederea RIH cu virusul West Nile. [The effect of conditions of collection and preservation of serum until the time of testing on the efficiency of adsorption with kaolin or extraction with acetone for the purpose of hemagglutination inhibition with West Nile virus]. Studii si Cercetari de Inframicrobiologie. 1969; 20(5): 365-72. ISSN: 0039-3975. In Romanian.
Descriptors: sampling procedures, guidelines for collection and preservation of sera, preparation of hemagglutination inhibition.

Duca, M; Buiuc, D; Duca, E. Dynamics of hemagglutination inhibition antibodies in white mice inoculated with West Nile virus. Specificity of the immunoglobulin fractions. Revue Roumaine d'Inframicrobiologie. 1969; 6 (4): 257-261.

NAL Call No.: 448.3 R323
Descriptors: immunology, dynamics of various antibodies, white mice, immunoglobulin fractions.

Haahr, S. The possible role of circulating interferon on autointerference in mice infected intraperitoneally with West Nile virus. Acta Pathologica et Microbiologica Scandinavica. 1969; 77(3): 425-32. ISSN: 0365-5555.

NAL Call No.: 448.3 Ac8
Descriptors: mortality, heamagglutionation tests, hydrocortisone, therapeutic use, intraperitoneal injection, neutralization tests, Semliki Forest virus, time factors.

Haahr, S. The occurrence of virus and interferon in spleen, serum and brain in steroid-treated mice under experimental infection with West Nile virus. Acta Pathologica et Microbiologica Scandinavica. 1969; 75(2): 303-12. ISSN: 0365-5555.

Descriptors: hydrocortisone, injection, experimental infection of mice, intraperitoneal injections, lymphoid tissue, physiology, methods, organ weights, time factors.

Haahr, S. The effects of antilymphocyte serum on viraemia and serum interferon of mice infected with West Nile virus. Acta Pathologica et Microbiologica Scandinavica. 1969; 77(1): 167-8 . ISSN: 0365-5555.

Descriptors: mice, rabbits, viral interference drug effects, interferons, blood cell count, lymphocytes, blood cell count, lymphocytes, lymphoid tissue.

McIntosh, BM; McGillivray, GM; Dickinson, DB; Taljaard, JJ. Ecological studies on Sindbis virus and West Nile virus in South Africa. IV. Infection in a wild avian population Ploceus-velatus. South African Medical Journal. 1969; 33 (4): 105-112.
Descriptors: animal viruses, Aves, birds, biochemistry, Ploceus velatus, ecology of the virus, disease reservoirs, wild birds, disease transmission.

Seledtsov, II; Kostyrko, IN. Predvaritel'nye dannye o vozmozhnoi roli Culicoides nubeculosus v tsirkuliatsii virusa Zapadnogo Nila. [Preliminary findings on the possible role of Culicoides nubeculosus in circulating West Nile Fever virus]. Meditsinskaia Parazitologiia i Parazitarnye Bolezni. 1969 Jul-Aug; 38(4): 496. ISSN: 0025-8326. In Russian.

NAL Call No.: 448.8 M469
Descriptors: insect vectors of disease, biting flies, Culicoides nubeculosus, disease carriers, transmission factors.

Tamalet, J; Toga, M; Chippaux-Hyppolite, C; Choux, R; Cesarini, JP. Encephalite experimentale a virus West-Nile de la sourISSN: aspects ultrastructuraux du systeme nerveux central. [Experimental encephalitis caused by West-Nile virus in mice: ultrastructural aspects of the central nervous system]. Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences. Serie D Sciences Naturelles. 1969 Aug 4; 269(5): 668-71. ISSN: 0567-655X. In French.

NAL Call No.: 505 P21 (3)
Descriptors: horses, mice, virus replication, pathology, electron microscopy, changes in neural tissue.

Rozeboom, L.E.; E. Kassira. Dual infections of mosquitoes with strains of West Nile virus. Journal of Medical Entomology, Oct 30, 1969, 6 (4): 407-411.

Descriptors: Culex pipiens molestus, mosquito, West Nile virus, experimental infection, white Swiss mice, resistence, antigenicity.

Butenko, AM. West Nile virus in the USSR. Part 2. Serological identification of Astrakhan tick-borne strains of West Nile virus. Trudy Instituta Poliomielita i Virusnykh Entsefalitov Akademii Meditsinskikh Nauk SSSR. 1968; 12: 374-388.
Descriptors: animal viruses, Acarina, Chelicerata, blood forming organs, body fluids, lymph studies.

Buttner, DW. Crystalloid structures in the cytoplasm of lymphatic cells of various monkeys Yellow Fever virus, West Nile virus, Rubella virus. Experientia. 1968; 24 (3): 261-262. ISSN: 0014-4754.

NAL Call No.: 475 Ex7
Descriptors: animal viruses, crystalloid structures, microscopy, lymphatic tissue, non-human primates.

Chumakov, MP; Belyaeva, AN; Butenko, AM; Mart-Yanova, LI. West Nile virus in the USSR. Part 1. Isolation of West Nile virus strains from Hyalomma-plumbeum-plumbeum. Trudy Instituta Poliomielita i Virusnykh Entsefalitov Akademii Meditsinskikh Nauk SSSR. 1968; 12: 365-373.
Descriptors: animal viruses, Acarina ticks, Hyalomma plumbeum, comparative morphology, physiology and pathology, temperature effects, virus isolation, viral strains, insect disease vectors.

Guillon, JC; Oudar, J; Joubert, L; Hannoun, C. Lesions histologiques du systeme nerveux dans l'infection a virus West Nile chez le cheval. [Histological lesions of the nervous system in West Nile virus infection in horses]. Annales de l'Institut Pasteur. 1968 Apr; 114(4): 539-50. ISSN: 0020-2444. In French.

NAL Call No.: 448.3 AN75
Descriptors: brain stem pathology, horse disease, pathology, viral isolation and purification.

Haahr, S. The occurrence of virus and interferon in the spleen, serum and brain in mice after experimental infection with West Nile virus. Acta Pathologica et Microbiologica Scandinavica. 1968; 74(3): 445-57. ISSN: 0365-5555

NAL Call No.: 448.3 Ac8
Descriptors: etiology, biosynthesis of interferons, blood, grain tissue analysis, mice spleen analysis, splenectomy, viral isolation and purification.

Hoffmann, L; Mouchet, J; Rageau, J; Hannoun, C; Joubert, L; Oudar, J; Beytout, D. Epidemiologie du virus West Nile: etude d'un foyer en Camargue. II. Esquisse du milieu physique, biologique et humain. [Epidemiology of the West Nile virus: study of an outbreak in Camargue. II. Outline of the physical, biological and human environment]. Annales de l'Institut Pasteur. 1968 Apr; 114(4): 521-38. ISSN: 0020-2444. In French.

NAL Call No.: 448.3 AN75
Descriptors: epidemiology, disease outbreaks, disease reservoirs, Culex mosquitoes, climate and inverimental factors.

Jarman, RV; Morgan, PN; Duffy, CE. Persistence of West Nile virus in L-929 mouse fibroblasts. Proceedings of the Society for Experimental Biology and Medicine. 1968 Nov; 129(2): 633-7. ISSN: 0037-9727.

NAL Call No.: 442.9 So1
Descriptors: immunodiffusion, mice, tissue culture, immunology.

Katz, E; Goldblum, N. Isolation of an "antigenic variant" of West Nile virus, originating from a chronic infection of the virus in LLC cells. Israel Journal of Medical Sciences. 1968 Jul-Aug; 4(4): 911-3. ISSN: 0021-2180.

NAL Call No.: R97.I87
Descriptors: immunodiffusion, mice, tissue culture, immunology.

Katz, E; Goldblum, N. Establishment, steady state and cure of a chronic infection of LLC cells with West Nile virus. Archiv fur die Gesamte Virusforschung. 1968; 25(1): 69-82. ISSN: 0003-9012.

NAL Call No.: 448.3 AR23
Descriptors: chick embryos, cytarobine pharmacology, fibroblasts, fluorescent antibody techniques, various drugs, haplorhine, idoturidine, interferon metabolism, phenylalanine.

Katz, E; Goldblum, N. Selection of a "temperature" resistant mutant of West Nile virus. Archiv fur die Gesamte Virusforschung. 1968; 25(1): 65-8. ISSN: 0003-9012.

NAL Call No.: 448.3 AR23
Descriptors: tissue culture, selection genetics, temperature as a selection factor.

Koller, M; Sekeyova, M; Gresikova, M. Study on a serum inhibitor to West Nile virus. Acta Virologica. 1968 Mar; 12(2): 184. ISSN: 0001-723X.

NAL Call No.: 448.3 Ac85
Descriptors: guinea pigs, hemagglutination inhibition tests, horses, mice, rabbits, virus inhibitors.

Nir, Y; Goldwasser, R; Lasowski, Y; Margalit, J. Isolation of West Nile virus strains from mosquitoes in Israel. American Journal of Epidemiology. 1968 Mar; 87(2): 496-501. ISSN: 0002-9262.

NAL Call No.: 449.8 Am3
Descriptors: Anopheles, Culex, mosquitoes as insect vectors, virus isolation and purification.

Peleg, J. Growth of arboviruses in primary tissue culture of Aedes-aegypti embryos Eastern equine encephalomyelitis virus, Semliki Forest virus, West Nile virus. American Journal of Tropical Medicine and Hygiene. 1968; 17 (2): 219-223. ISSN: 0002-9637.

NAL Call No.: 448.8 Am326

Descriptors: animal viruses, cell culture, Aedes aegypti embryos, growth in culture, comparative growth, culture media.

Peries, J; Canivet, M; Gullemain, B; Boiron, M. Inhibitory effect of interferon preparations on the development of foci of altered cells induced in-vitro by mouse sarcoma virus, West Nile virus, Swiss mouse embryo. Journal of General Virology. 1968; 3 (PART 3): 465-468. ISSN: 0022-1317.
NAL Call No.: QR360.A1J6

Descriptors: animal virus, mice model, biochemical studies, proteins, peptides, methods, developmental biology, interferon, cell cultures.

Shalunova, NV; Zgurskaya, GN; Berezin, VV. West Nile virus in the USSR. Part 3. Isolation of another strain of West Nile virus from Hyalomma-plumbeum-plumbeum panz in Astrakhan Oblast in 1965. Trudy Instituta Poliomielita i Virusnykh Entsefalitov Akademii Meditsinskikh Nauk SSSR. 1968; 12: 389-393.
Descriptors: animal viruses, ticks, Acarina, isolation of virus strains, insect vectors, disease reservoirs, environmental effects.

Thion, P.Y. The normal electroencephalogram of horses, its variations in meningoencephalomyelitis caused by West-Nile virus. Lyons. Ecole nationale veterinaire. These. 1968, no. 31. Lyon, 44 p. ill. In French. Bibliography: p. [43]-44.

NAL Call No.: 41.2 L99 1968 No.31

Descriptors: West Nile virus, meningoencephalomyelitis, horses, electroencephalogram variations.

Eldadah, AH; Nathanson, N. Pathogenesis of West Nile virus encepahlitis in mice and rats. II. Virus multiplication, evolution of immunofluorescence, and development of histological lesions in the brain. American Journal of Epidemiology. 1967 Nov; 86(3): 776-90. ISSN: 0002-9262.

NAL Call No.: 449.8 Am3
Descriptors: etiology of arbovirus infections, viral growth and development, brain pathology, cerebral cortex pathology, fluorescent antibody technique, mice, rats, tssue culture, virus cultivation, newborn animals.

Eldadah, AH; Nathanson, N; Sarsitis, R. Pathogenesis of West Nile virus encephalitis in mice and rats. 1. Influence of age and species on mortality and infection. American Journal of Epidemiology. 1967 Nov; 86(3): 765-75. ISSN: 0002-9262.

Descriptors: etiology of arbovirus infections, viral growth and development, brain pathology, cerebral cortex pathology, antibody development, hamsters, mice, rats, experimental animal models, hemagglutination inhibition tests, newborn animals, age factors, species specificity and virulence.

Filipe, A R. Anticorpos contra virus transmitidos por artropodos arbovirus do grupo B em animais do sul de Portugal. Inquerito serologico preliminar com o virus West Nile, estirpe Egypt 101. [Antibodies against virus transmitted by arbovirus of the B group arthropods in animals of the south of Portugal. Preliminary blood analysis with the West Nile virus, Egypt 101 species]. Anais da Escola Nacional de Saude Publica e de Medicina Tropical. 1967 Jan-Dec; 1(1): 197-204. ISSN: 0075-9767. In Portuguese.
Descriptors: antibodies, arboviruses, immunology, domestic animals, dogs, goats, sheep, public health concerns, veterinary medicine, Portugal.

Neustroev, VD; Rezepova, AI. Izuchenie gemaggliutiniruiushchikh svoistv virusa zapadnogo Nila. [A study of the hemagglutinating properties of West Nile virus]. Voprosy Virusologii. 1967 May-Jun; 12(3): 290-5.ISSN: 0507-4088. In Russian.

NAL Call No.: 448.8 P942
Descriptors: antigens, viral immunology, drug effects, hemagglutination inhibition tests, viral hemagglutinins, lactones pharmacology, virus cultivation.

Price, WH; O'Leary, W. Geographic variation in the antigenic character of West Nile virus. American Journal of Epidemiology. 1967 Jan; 85(1): 84-6. ISSN: 0002-9262.

Descriptors: immunology, Congo, Egypt, hemagglutination inhibition tests, India, Pakistan.

Ramachandra, Rao. Vector control in Asia. Human mosquito borne viruses: Japanese encephalitis, Culex-tritaencorhynchus, Culex-gelidus, West Nile virus, Sindbis virus. Japanese Journal of Medical Science and Biology. 1967; 20 (SUPP): 59-60. ISSN: 0021-5112.

NAL Call No.: R97.J28
Descriptors: animal viruses, Culex tritaencorhynchus, Culex gleidus, mosquitoes as insect vectors, public health concerns, vector control.

Vilner, LM; Chumakov, MP; Zeitlenok, NA; Goldfarb, MM; Rodin, IM; Brodskaya, LM; Finogenova, EV. Study of optimal conditions for interferon formation during arboviral infections of chick embryo cell cultures, Semliki Forest virus, Chichungunya virus, tick borne encephalitis virus, West Nile virus. Antibiotiki. 1967; 12 (12): 1093-1099. ISSN: 0003-5637.

NAL Call No.: 396.8 AN84
Descriptors: animal viruses, chick embryo cell cultures, interferon formation, comparative study, materials, media, and methods, viral development.

Donaldson, JM. An assessment of Culex pipiens quinquefasciatus say as a vector of viruses in the Witwatersrand region of the Transvaal. I. West Nile virus. South African Journal of Medical Sciences. 1966 Jul; 31(1): 1-10. ISSN: 0038-2310.
Descriptors: insect vectors, Culex mosquitoes, viral reservoir, transmission, birds, poultry, mice, South Africa.

Pantheir, R; Hannoun, C; Oudar, J; Beytout, D; Corniou, B; Joubert, L; Guillon, J C; Mouchet, J. Isolement du virus West Nile chez un cheval de Camargue atteint d'encephalomyelite. [Isolation of West Nile virus in a Camarge horse with encephalomyelitis]. Compte Rendus Hebdomadaires des Seances de l'Academie des Sciences. Serie D Sciences Naturelles. 1966 Mar 14; 262(11): 1308-10. ISSN: 0567-655X. In French.
NAL Call No.: 505 P21 (3)
Descriptors: encephalitis virus isolation and purification, horses, complement fixation tests, France.

Rozeboom, LE; Behin, R; Kassira, EN. Dual infections of Aedes aegypti L. with Plasmodium gallinaceum Brumpt and West Nile virus. Journal of Parasitology. 1966 Jun; 52(3): 579-82. ISSN: 0022-3395.

NAL Call No.: 448.8 J824
Descriptors: Aedes mosquitoes, insect vectors, Plasmodium gallinaceum, Aedes aegypti, effects of dual infections, viral interference.

Nir, Y; Beemer, A; Goldwasser, RA. West Nile virus infection in mice following exposure to a viral aerosol. British Journal of Experimental Pathology. 1965 Aug; 46(4): 443-9. ISSN: 0007-1021
NAL Call No.: 448.8 B772
Descriptors: aerosols, arbovirual infections, mice exposed to air borne virus, antigen-antibody reactions, various organ pathology, fluorescent antibody techniques, brain, kidney, liver, lung, lymph nodes, lung, nasal mucosa, spleen.

Shirodkar, M V. The blocking effect of West Nile virus on production of sarcoma by Rous virus in chickens. Journal of Immunology. 1965 Dec; 95(6): 1121-8. ISSN: 0022-1767.

NAL Call No.: 448.8 J8232
Descriptors: interferons for therapeutic use, Sarcoma, experimental drug therapy, mice embryos, genetic code, interferons antagonists and inhibitors, protein biosynthesis, RNA, transfer metabolism, tissue culture, virus replication.