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United States Articles found through PubMed 2000-2012

Description

West Nile Virus (WNV) is a mosquito-borne virus that can infect humans. Originally known in East Africa, WNV has now spread throughout the world. The first case of WNV in the western hemisphere was identified in New York in 1999, and within 5 years the disease had spread throughout the United States and into Canada, Latin America, and the Caribbean. While most of WNV infections cause no symptoms, the remaining cases show flu-like symptoms, and can lead to neurological disease or death.

latest article added on November 2013

ArticleFirst AuthorPublished
West Nile Virus Antibody Prevalence in Red-Winged Blackbirds ( Agelaius phoeniceus ) from North Dakota, USA (2003–2004) Sullivan, Heather2006

West Nile Virus Antibody Prevalence in Red-Winged Blackbirds ( Agelaius phoeniceus ) from North Dakota, USA (2003–2004)

Keywords

WNV

Abstract

This study was designed to explore the role that red-winged blackbirds (Agelaius phoeniceus) may have played in disseminating West Nile virus (WNV) across the United States. Using enzyme-linked immunosorbent assays designed to detect WNV antibodies in avian species we were able to determine the WNV antibody prevalence in a cohort of red-winged blackbirds in central North Dakota in 2003 and 2004. The peak WNV antibody prevalence was 22.0% in August of 2003 and 18.3% in July of 2004. The results of this study suggest that red-winged blackbird migratory populations may be an important viral dispersal mechanism with the ability to spread arboviruses such as WNV across the United States.

Authors

Linz, George, Clark, Larry, Sullivan, Heather and Salman, Mo

Year Published

2006

Publication

Vector-Borne and Zoonotic Diseases

Locations
DOI

10.1089/vbz.2006.6.305

Additional Information:

http://www.ncbi.nlm.nih.gov/pubmed/16989570

Serologic Evidence of West Nile Virus Infection in Three Wild Raptor PopulationsStout, William E.2005

Serologic Evidence of West Nile Virus Infection in Three Wild Raptor Populations

Keywords

West Nile virus, passive maternal antibody transmission, Cooper's hawk, great horned owl, red-tailed hawk, WNV

Abstract

We assayed for West Nile virus (WNV) antibodies to determine the presence and prevalence of WNV infection in three raptor populations in southeast Wisconsin during 2003–04. This study was conducted in the framework of ongoing population studies that started before WNV was introduced to the study area. For 354 samples, 88% of 42 adult Cooper's hawks (Accipiter cooperii), 2.1% of 96 nestling Cooper's hawks, 9.2% of 141 nestling red-tailed hawks (Buteo jamaicensis), and 12% of 73 nestling great horned owls (Bubo virginianus) tested positive for WNV antibodies by the constant virus–serum dilution neutralization test. Samples that tested positive for WNV antibodies were collected across a wide variety of habitat types, including urban habitats (both high and low density), roads, parking areas, recreational areas, croplands, pastures, grasslands, woodlands, and wetlands. Based on the increased prevalence and significantly higher WNV antibody titers in adults compared with nestlings, we suggest that nestlings with detectable antibody levels acquired these antibodies through passive transmission from the mother during egg production. Low levels of WNV antibodies in nestlings could serve as a surrogate marker of exposure in adult raptor populations. Based on breeding population densities and reproductive success over the past 15 yr, we found no apparent adverse effects of WNV infections on these wild raptor populations.

Authors

Stout, William E., Cassini, Andrew G., Meece, Jennifer K., Papp, Joseph M., Rosenfield, Robert N. and Reed, Kurt D.

Year Published

2005

Publication

Avian Diseases

Locations
DOI

10.1637/7335-012805R1.1

Additional Information:

http://www.ncbi.nlm.nih.gov/pubmed/16252490

The fog of war: Why the environmental crusade for anadromous fish species in California could disarm the State’s local vector control districts in their war against mosquitoesSiptroth, Stephen M.2011

The fog of war: Why the environmental crusade for anadromous fish species in California could disarm the State’s local vector control districts in their war against mosquitoes

Keywords

Clean Water Act; Vector control district; Mosquito; Malaria; West Nile virus; California, WNV

Abstract

In California, local mosquito and vector control districts have successfully controlled mosquito and vector-borne diseases by improving drainage patterns and applying pesticides. The Bay-Delta Conservation Plan, which is a proposed habitat conservation plan for the Sacramento-San Joaquin Bay-Delta estuary, proposes to add over 70,000 acres of habitat in the Delta to improve conditions for threatened and endangered aquatic and terrestrial species. This habitat could also be a suitable mosquito breeding habitat, which will be located in close proximity to urban and suburban communities. Wetland management practices and continued pesticide applications in the Delta could mitigate the effects of a new mosquito breeding habitat. Recent legal developments, however, require districts to obtain and comply with Clean Water Act permits, which restrict the application of pesticides in or near waters of the United States. Moreover, the U.S. Environmental Protection Agency has taken the first step in a rulemaking process that could further limit or prohibit the use of certain vector control pesticides in the Delta. In the near term and until less harmful methods for mosquito control are available, local vector control districts’ application of mosquito control pesticides should be exempt from Clean Water Act permit requirements.

Authors

Siptroth, Stephen M. and Shanahan, Richard P.

Year Published

2011

Publication

Journal of Epidemiology and Global Health

Locations
DOI

10.1016/j.jegh.2011.06.001

Additional Information:

http://www.ncbi.nlm.nih.gov/pubmed/23856372

Avian Host-Selection by Culex pipiens in Experimental TrialsSimpson, Jennifer E.2009

Avian Host-Selection by Culex pipiens in Experimental Trials

Keywords

WNV

Abstract

Evidence from field studies suggests that Culex pipiens, the primary mosquito vector of West Nile virus (WNV) in the northeastern and north central United States, feeds preferentially on American robins (Turdus migratorius). To determine the contribution of innate preferences to observed preference patterns in the field, we conducted host preference trials with a known number of adult female C. pipiens in outdoor cages comparing the relative attractiveness of American robins with two common sympatric bird species, European starling, Sternus vulgaris and house sparrow, Passer domesticus. Host seeking C. pipiens were three times more likely to enter robin-baited traps when with the alternate host was a European starling (n = 4 trials; OR = 3.06; CI [1.42-6.46]) and almost twice more likely when the alternative was a house sparrow (n = 8 trials; OR = 1.80; CI = [1.22-2.90]). There was no difference in the probability of trap entry when two robins were offered (n = 8 trials). Logistic regression analysis determined that the age, sex and weight of the birds, the date of the trial, starting-time, temperature, humidity, wind-speed and age of the mosquitoes had no effect on the probability of a choosing a robin over an alternate bird. Findings indicate that preferential feeding by C. pipiens mosquitoes on certain avian hosts is likely to be inherent, and we discuss the implications innate host preferences may have on enzootic WNV transmission.

Authors

Simpson, Jennifer E., Folsom-O'Keefe, Corrine M., Childs, James E., Simons, Leah E., Andreadis, Theodore G. and Diuk-Wasser, Maria A.

Year Published

2009

Publication

PLOS One

Locations
DOI

10.1371/journal.pone.0007861

Additional Information:

http://www.ncbi.nlm.nih.gov/pubmed/19924251

West Nile Virus Antibodies in Permanent Resident and Overwintering Migrant Birds in South-Central KansasShelite, Thomas R.2008

West Nile Virus Antibodies in Permanent Resident and Overwintering Migrant Birds in South-Central Kansas

Keywords

WNV

Abstract

We conducted serological studies, using epitope-blocking ELISAs directed at West Nile virus (WNV) and flavivirus antibodies, of wild birds in south-central Kansas, the first for this state, in the winters of 2003-04 through 2005-06. Overwintering migratory species (primarily the American tree sparrow and dark-eyed junco) consistently showed significantly lower seropositivity than permanent residents (primarily the northern cardinal). The cardinal showed annual variation in seropositivity between winters. Of 35 birds that were serial sampled within a single winter, one cardinal may have seroconverted between late December and mid-February, providing a preliminary suggestion of continued enzootic transmission, chronic infection, or bird-bird transfer as overwintering mechanisms. Breeding population size of the cardinal did not change after the introduction of WNV to Kansas. Of eighteen birds that were serial sampled between winters, none seroconverted. Among overwintering migrants, the Harris' Sparrow showed the highest seropositivity, possibly related to its migration route through the central Great Plains, an area of recent high WNV activity. The finding that permanent resident birds exhibit higher seropositivity than migrant birds suggests that resident birds contribute to the initiation of annual infection cycles,although this conclusion is speculative in the absence of data on viral titers and the length of viremia. KeyWords: West Nile Virus-flavivirus-birds-epitope-blocking ELISA-winter.

Authors

Shelite, Thomas R., Rogers, Christopher M., Litzner, Brandon R., Johnson, R. Roy and Schneegurt, Mark A.

Year Published

2008

Publication

Vector-Borne and Zoonotic Diseases

Locations
DOI

10.1089/vbz.2007.0176

Additional Information:

http://www.ncbi.nlm.nih.gov/pubmed/18471059

Drought-Induced Amplification and Epidemic Transmission of West Nile Virus in Southern FloridaShaman, Jeffrey2005

Drought-Induced Amplification and Epidemic Transmission of West Nile Virus in Southern Florida

Keywords

West Nile virus, amplification, transmission, Culex nigripalpus, drought, WNV

Abstract

We show that the spatial-temporal variability of human West Nile (WN) cases and the transmission of West Nile virus (WNV) to sentinel chickens are associated with the spatial-temporal variability of drought and wetting in southern Florida. Land surface wetness conditions at 52 sites in 31 counties in southern Florida for 2001–2003 were simulated and compared with the occurrence of human WN cases and the transmission of WNV to sentinel chickens within these counties. Both WNV transmission to sentinel chickens and the occurrence of human WN cases were associated with drought 2–6 mo prior and land surface wetting 0.5–1.5 mo prior. These dynamics are similar to the amplification and transmission patterns found in southern Florida for the closely related St. Louis encephalitis virus. Drought brings avian hosts and vector mosquitoes into close contact and facilitates the epizootic cycling and amplification of the arboviruses within these populations. Southern Florida has not recorded a severe, widespread drought since the introduction of WNV into the state in 2001. Our results indicate that widespread drought in the spring followed by wetting during summer greatly increase the probability of a WNV epidemic in southern Florida.

Authors

Day, Jonathan F., Shaman, Jeffrey and Stieglitz, Marc

Year Published

2005

Publication

Journal of Medical Entomology

Locations
DOI

10.1603/0022-2585(2005)042[0134:DAAETO]2.0.CO;2

Additional Information:

http://www.ncbi.nlm.nih.gov/pubmed/15799522

Achieving Operational Hydrologic Monitoring of Mosquitoborne DiseaseShaman, Jeffrey2005

Achieving Operational Hydrologic Monitoring of Mosquitoborne Disease

Keywords

WNV

Abstract

Mosquitoes and mosquitoborne disease transmission are sensitive to hydrologic variability. If local hydrologic conditions can be monitored or modeled at the scales at which these conditions affect the population dynamics of vector mosquitoes and the diseases they transmit, a means for monitoring or modeling mosquito populations and mosquitoborne disease transmission may be realized. We review how hydrologic conditions have been associated with mosquito abundances and mosquitoborne disease transmission and discuss the advantages of different measures of hydrologic variability. We propose that the useful application of any measure of hydrologic conditions requires additional consideration of the scales for both the hydrologic measurement and the vector control interventions that will be used to mitigate an outbreak of vectorborne disease. Our efforts to establish operational monitoring of St. Louis encephalitis virus and West Nile virus transmission in Florida are also reviewed.

Authors

Day, Jonathan F. and Shaman, Jeffrey

Year Published

2005

Publication

Emerging Infectious Diseases

Locations
DOI

10.3201/eid1109.050340

Additional Information:

http://www.ncbi.nlm.nih.gov/pubmed/16229760

Hydrologic Conditions Describe West Nile Virus Risk in ColoradoShaman, Jeffrey2010

Hydrologic Conditions Describe West Nile Virus Risk in Colorado

Keywords

WNV

Abstract

We examine the relationship between hydrologic variability and the incidence of human disease associated with West Nile virus (WNV; family Flaviviridae, genus Flavivirus) infection (hereafter termed "human WN cases") in Colorado from 2002 to 2007. We find that local hydrologic conditions, as simulated by the Mosaic hydrology model, are associated with differences in human WN cases. In Colorado's eastern plains, wetter spring conditions and drier summer conditions predict human WN cases. In Colorado's western mountains, drier spring and summer conditions weakly predict human WN cases. These findings support two working hypotheses: (1) wet spring conditions increase the abundance of Culex tarsalis vectors in the plains, and (2) dry summer conditions, and respondent irrigational practices during such droughts, favor Cx. pipiens and Cx. tarsalis abundance throughout Colorado. Both of these processes potentially increase the local vector-to-host ratio, favoring WNV amplification among competent avian hosts and bridging to humans.

Authors

Shaman, Jeffrey, Day, Jonathan F. and Komar, Nicholas

Year Published

2010

Publication

International Journal of Environmental Research and Public Health

Locations
DOI

10.3390/ijerph7020494

Additional Information:

http://www.ncbi.nlm.nih.gov/pubmed/20616987

Meteorological and Hydrological Influences on the Spatial and Temporal Prevalence of West Nile Virus in Culex Mosquitoes, Suffolk County, New YorkShaman, Jeffrey2011

Meteorological and Hydrological Influences on the Spatial and Temporal Prevalence of West Nile Virus in Culex Mosquitoes, Suffolk County, New York

Keywords

West Nile virus, hydrology, meteorology, transmission, amplification, WNV

Abstract

The factors determining the spatial and temporal distribution of West Nile virus (family Flaviviridae, genus Flavivirus, WNV) activity are not well understood. Here, we explore the effects of hydrological and meteorological conditions on WNV infection among Culex genus mosquitoes collected during 2001–2009 in Suffolk County, Long Island, NY. We show that WNV infection rates in assayed pools of Culex mosquitoes are associated in both space and time with hydrological and meteorological variability. Specifically, wet winter, warm and wet spring conditions, and dry summer conditions are associated with the increased local prevalence of WNV among Culex mosquitoes during summer and fall. These findings indicate that within Suffolk County, and for a given year, areas at risk for heightened WNV activity may be identified in advance by using hydrology model estimates of land surface wetness and observed meteorological conditions.

Authors

Shaman, Jeffrey, Harding, Kerri and Campbell, Scott R.

Year Published

2011

Publication

Journal of Medical Entomology

Locations
DOI

10.1603/ME10269

Additional Information:

http://www.ncbi.nlm.nih.gov/pubmed/21845947

Survey of Aedes triseriatus (Diptera: Culicidae) for Lacrosse Encephalitis Virus and West Nile Virus in Lorain County, OhioScheidler, Lydia C.2006

Survey of Aedes triseriatus (Diptera: Culicidae) for Lacrosse Encephalitis Virus and West Nile Virus in Lorain County, Ohio

Keywords

West Nile virus, La Crosse encephalitis virus, surveillance, arbovirus, Aedes triseriatus, WNV

Abstract

From June through September 2003, we conducted a survey of female Aedes triseriatus (Say) for infection with La Crosse encephalitis virus (family Bunyaviridae, genus Orthobunyavirus, LACV) and West Nile virus (family Flaviviridae, genus Flavivirus, WNV) at three locations in Lorain County, Ohio. To determine infection rate and seasonal variation of both viruses in the Ae. triseriatus population, Ae. triseriatus were collected weekly by using gravid traps and CO2-baited CDC light traps and tested for virus by using reverse transcriptase polymerase chain reaction. In total, 170 pools comprised of 2,143 females were tested for LACV, of which seven were positive; the maximum likelihood estimate of infection rate combined throughout the season was 3.22/1,000. None of 170 pools comprised of 2,158 females tested for WNV were positive. LACV-positive pools were detected between late July and early September.

Authors

Scheidler, Lydia C., Dunphy-daly, Meagan M., White, Bradley J., Andrew, David R., Mans, Nicole Z. and Garvin, Mary C.

Year Published

2006

Publication

Journal of Medical Entomology

Locations
DOI

10.1603/0022-2585(2006)43[589:SOATDC]2.0.CO;2

Additional Information:

http://www.ncbi.nlm.nih.gov/pubmed/16739420

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Temperature has played a critical role in the spatiotemporal dynamics of West Nile virus transmission throughout California from its introduction in 2003 through establishment by 2009. We compared two novel mechanistic measures of transmission risk, the temperature-dependent ratio of virus extrinsic incubation period to the mosquito gonotrophic period (BT), and the fundamental reproductive rati...

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Culex pipiens L. (Diptera: Culicidae) and Culex restuans Theobald are the primary enzootic and bridge vectors of West Nile virus in the eastern United States north of 36° latitude. Recent studies of the natural history of these species have implicated catch basins and underground storm drain systems as important larval development sites in urban and suburban locales. Although the presence of la...

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