Anonymous.
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.
NAL Call No.: RA407.3 M56
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.
NAL Call No.: RA407.3 M56
Anonymous.
NAL Call No.: RA407.3 M56
Anonymous.
NAL Call No.: RA407.3 M56
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.
NAL Call No.: 41.8 Am3
Descriptors: virology, prevention and control, isolation and purification, songbirds virology, Rhode Island, epidemiology, mosquito control.
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.]
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.
Descriptors: epidemiology,
disease prevention and control, disease incidence, disease risk factors, Rhode
Island.
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.
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.
Descriptors: surveillance
data, Culex mosquitoes, RNA, viral genetics, behavior of overwintering mosquitoes,
insect vectors and reservoirs, New York City.
NAL Call No.: RA407.3 M56
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.
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.
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.
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.
NAL Call No.: 470 Sci25
Descriptors: epidemiology, songbird surveillance, chickens,
Culicidae mosquito vectors, disease prevention and control.
Hubalek, Z.
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.
Johnston, BL; Conly, JM.
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.
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.
Lustig, S; Halevy,
M; Fuchs, P; Ben Nathan, D; Lachmi, B E; Kobiler, D; Israeli, E; Olshevsky,
U.
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.
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.
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.
Nolen, RS. West
Nile virus survives winter; no surprise, says CDC.
NAL Call No.: 41.8 Am3
Descriptors: disease
vector reservoirs, overwintering of Culex mosquitoes, transmission patterns,
migratory birds, raptors, New York, Connecticut.
Nolen, RS.
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.
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.
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.
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.
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.
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.
Descriptors: horses, birds,
insect vectors, detection by ELISA, Europe, France, risk of re-emergence.
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February 10, 2003