Vector-Borne Diseases Active
Vector-borne diseases are transmitted from one animal to another by vectors, including insects, such as mosquitoes or fleas, and arachnids, such as ticks. The USGS National Wildlife Health Center investigates wildlife diseases, including vector-borne diseases, such as West Nile virus and sylvatic plague.
The following are vector-borne diseases currently being studied by the USGS National Wildlife Health Center (NWHC).
West Nile Virus
West Nile virus, a mosquito-transmitted virus, was introduced into the New York City area of North America in 1999. Since then the virus has been transmitted throughout the continental U.S., southern Canadian Provinces, Mexico. The virus has also been transmitted on the Caribbean islands, Central and South America. West Nile virus causes disease symptoms, including encephalitis, in humans and horses, but has been devastating to North American wild bird populations, particularly the corvids, raptors, and songbirds. Population declines in members of these bird groups have been documented and linked to the year West Nile virus emerged in states or geographic areas of the U.S.
The NWHC has been involved with West Nile virus surveillance in wild birds and research since the entry of the virus into the U.S. In recent years we have assisted states and Tribes in monitoring for virus transmission in ruffed grouse (Bonasa umbellus), snow shoe hares (Lepus americanus), and wild wolves (Canus lupus). Experimentally, the NWHC has been working to develop models of West Nile virus susceptibility in passerine, or song birds, using domesticated zebra finches (Taeniopygia guttata) and canaries (Serinus canaria), which show lower and higher susceptibility to the virus, respectively. Since the genome of these domesticated birds has been published studies on molecular basis of disease susceptibility are possible.
West Nile virus continues to circulate every summer in the U.S. An uptick in human, domestic animal, and avian cases, might be related to weather, with hot and dry conditions being permissive, and also cycles of immunity in birds, the primary host for the virus.
To see disease reports of West Nile virus, search WHISPers (Wildlife Health Information Sharing Partnership event reporting system.
To check out historic fact sheets on West Nile virus, see – NWHC Fact Sheets.
Sylvatic Plague
Sylvatic plague, caused by Yersinia pestis, is a bacterial disease transmitted by fleas that afflicts many mammalian species, including humans. For many species of wildlife, plague mortality is a serious conservation issue. Current efforts to halt the spread of plague in prairie dog colonies typically rely on dusting individual prairie dog burrows with pesticides to kill plague-infected fleas. Although flea-control insecticides, such as deltamethrin, are useful in stopping plague outbreaks in these prairie dog colonies, dusting of burrows is labor intensive and time consuming and may affect other insects and arthropods.
Scientists at the USGS National Wildlife Health Center (NWHC), in collaboration with colleagues at the University of Wisconsin (UW), have developed a sylvatic plague vaccine that shows great promise in protecting prairie dogs against plague. Controlling plague is a vital concern for ongoing management and conservation efforts for prairie dogs.
To learn more about sylvatic plague and read related publications, see – Sylvatic Plague and Vaccines.
Below are other science projects related to vector-borne diseases.
Below are publications related to vector-borne diseases.
Experimental susceptibility of Wood Ducks (Aix sponsa) for West Nile virus
Utilizing hunter harvest effort to survey for wildlife disease: a case study of West Nile virus in greater sage-grouse
West Nile Virus transmission in winter: the 2013 Great Salt Lake Bald Eagle and Eared Grebes Mortality event
West nile virus in American white pelican chicks: transmission, immunity, and survival
Characterization of West Nile viruses isolated form captive American flamingoes (Phoenicopterus ruber) in Medellin, Colombia.
Prevalence and effects of West Nile virus on wild American kestrel (Falco sparverius) populations in Colorado
Seroprevalence of West Nile Virus in feral horses on Sheldon National Wildlife Refuge, Nevada, United States
West Nile virus: North American experience
Severe bill deformity of an American Kestrel wintering in California
Climate change and wildlife health: direct and indirect effects
Occurrence of West Nile virus infection in raptors at the Salton Sea, California
Occurrence of avian Plasmodium and West Nile virus in culex species in Wisconsin
Below are news stories associated with this project.
Below are FAQs associated related to vector-borne diseases.
- Overview
Vector-borne diseases are transmitted from one animal to another by vectors, including insects, such as mosquitoes or fleas, and arachnids, such as ticks. The USGS National Wildlife Health Center investigates wildlife diseases, including vector-borne diseases, such as West Nile virus and sylvatic plague.
The following are vector-borne diseases currently being studied by the USGS National Wildlife Health Center (NWHC).
West Nile Virus
West Nile virus, a mosquito-transmitted virus, was introduced into the New York City area of North America in 1999. Since then the virus has been transmitted throughout the continental U.S., southern Canadian Provinces, Mexico. The virus has also been transmitted on the Caribbean islands, Central and South America. West Nile virus causes disease symptoms, including encephalitis, in humans and horses, but has been devastating to North American wild bird populations, particularly the corvids, raptors, and songbirds. Population declines in members of these bird groups have been documented and linked to the year West Nile virus emerged in states or geographic areas of the U.S.
The NWHC has been involved with West Nile virus surveillance in wild birds and research since the entry of the virus into the U.S. In recent years we have assisted states and Tribes in monitoring for virus transmission in ruffed grouse (Bonasa umbellus), snow shoe hares (Lepus americanus), and wild wolves (Canus lupus). Experimentally, the NWHC has been working to develop models of West Nile virus susceptibility in passerine, or song birds, using domesticated zebra finches (Taeniopygia guttata) and canaries (Serinus canaria), which show lower and higher susceptibility to the virus, respectively. Since the genome of these domesticated birds has been published studies on molecular basis of disease susceptibility are possible.
West Nile virus continues to circulate every summer in the U.S. An uptick in human, domestic animal, and avian cases, might be related to weather, with hot and dry conditions being permissive, and also cycles of immunity in birds, the primary host for the virus.
To see disease reports of West Nile virus, search WHISPers (Wildlife Health Information Sharing Partnership event reporting system.
To check out historic fact sheets on West Nile virus, see – NWHC Fact Sheets.
Sylvatic Plague
Sylvatic plague, caused by Yersinia pestis, is a bacterial disease transmitted by fleas that afflicts many mammalian species, including humans. For many species of wildlife, plague mortality is a serious conservation issue. Current efforts to halt the spread of plague in prairie dog colonies typically rely on dusting individual prairie dog burrows with pesticides to kill plague-infected fleas. Although flea-control insecticides, such as deltamethrin, are useful in stopping plague outbreaks in these prairie dog colonies, dusting of burrows is labor intensive and time consuming and may affect other insects and arthropods.
Scientists at the USGS National Wildlife Health Center (NWHC), in collaboration with colleagues at the University of Wisconsin (UW), have developed a sylvatic plague vaccine that shows great promise in protecting prairie dogs against plague. Controlling plague is a vital concern for ongoing management and conservation efforts for prairie dogs.
To learn more about sylvatic plague and read related publications, see – Sylvatic Plague and Vaccines.
- Science
Below are other science projects related to vector-borne diseases.
- Publications
Below are publications related to vector-borne diseases.
Filter Total Items: 40Experimental susceptibility of Wood Ducks (Aix sponsa) for West Nile virus
Detection of West Nile virus (WNV) has been reported in a variety of wild ducks in the US, but little is known about the pathogenesis and outcome of exposure of the disease in these species. Previous experimental studies of WNV in ducks either have challenged a small number of ducks with WNV or have tested domesticated ducks. To determine susceptibility and immune response, we challenged 7-wk-oldAuthorsErik K. Hofmeister, Robert E. Porter, J. Christian FransonUtilizing hunter harvest effort to survey for wildlife disease: a case study of West Nile virus in greater sage-grouse
Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are highly susceptible to infection with West Nile virus (WNV), with substantial mortality reported in wild populations and in experimentally infected birds. Although sage-grouse are hunted throughout much of their range, they have also recently been considered for protection under the Endangered Species Act. We used blood samples collecAuthorsRobert J. Dusek, Christian A. Hagen, J. Christian Franson, David A. Budeau, Erik K. HofmeisterWest Nile Virus transmission in winter: the 2013 Great Salt Lake Bald Eagle and Eared Grebes Mortality event
West Nile Virus (WNV) infection has been reported in over 300 species of birds and mammals. Raptors such as eagles, hawks and falcons are remarkably susceptible, but reports of WNV infection in Bald Eagles (Haliaeetus leucocephalus) are rare and reports of WNV infection in grebes (Podicipediformes) even rarer. We report an unusually large wild bird mortality event involving between 15,000-20,000 EAuthorsHon S. Ip, Arnaud J. Van Wettere, Leslie McFarlan, Valerie I. Shearn-Bochsler, Sammie L. Dickson, JoDee Baker, Gary Hatch, Kimberly Cavender, Renee Romaine Long, Barbara L. BodensteinWest nile virus in American white pelican chicks: transmission, immunity, and survival
West Nile virus (WNV) causes significant mortality of American White Pelican chicks at northern plains colonies. We tested oropharyngeal/cloacal swabs from moribund chicks for shed WNV. Such shedding could enable chick-to-chick transmission and help explain why WNV spreads rapidly in colonies. WNV was detected on swabs from 11% of chicks in 2006 and 52% of chicks in 2007; however, viral titers werAuthorsMarsha A. Sovada, Pamela J. Pietz, Erik K. Hofmeister, Alisa J. BartosCharacterization of West Nile viruses isolated form captive American flamingoes (Phoenicopterus ruber) in Medellin, Colombia.
Serum samples from a total of 71 healthy captive birds belonging to 18 species were collected in July of 2008 in Medellin (Colombia) and tested for flaviviruses. Eighteen of 29 samples from American Flamingoes (Phoenicopterus ruber) were positive for West Nile virus (WNV) by reverse transcription-polymerase chain reaction. Selected positive samples were serially passaged and WNV was confirmed by iAuthorsJorge E. Osorio, Karl A. Ciuoderis, Juan G. Lopera, Leidy D. Piedrahita, Darby Murphy, James LeVasseur, Lina Carrillo, Martha C. Ocampo, Erik HofmeisterPrevalence and effects of West Nile virus on wild American kestrel (Falco sparverius) populations in Colorado
To assess the potential impacts of West Nile virus (WNV) on a wild population of free-ranging raptors, we investigated the prevalence and effects of WNV on American Kestrels (Falco sparverius) breeding along the Front Range of the Rocky Mountains in northern Colorado. We monitored kestrel nesting activity at 131 nest boxes from March to August 2004. Of 81 nest attempts, we obtained samples from 11AuthorsRobert J. Dusek, William M. Iko, Erik K. HofmeisterSeroprevalence of West Nile Virus in feral horses on Sheldon National Wildlife Refuge, Nevada, United States
We screened 1,397 feral horses (Equus caballus) on Sheldon National Wildlife Refuge, Nevada, United States, for IgM and IgG against flavivirus during 2004–2006, 2008, and 2009. Positive serum samples were tested for neutralizing antibodies to West Nile virus (WNV) and St. Louis encephalitis virus (SLEV). One animal was positive for antibody against WNV in 2004, but all others tested in 2004–2006 wAuthorsJ. Christian Franson, Erik K. Hofmeister, Gail H. Collins, Robert J. DusekWest Nile virus: North American experience
West Nile virus, a mosquito-vectored flavivirus of the Japanese encephalitis serogroup, was first detected in North America following an epizootic in the New York City area in 1999. In the intervening 11 years since the arrival of the virus in North America, it has crossed the contiguous USA, entered the Canadian provinces bordering the USA, and has been reported in the Caribbean islands, Mexico,AuthorsErik K. HofmeisterSevere bill deformity of an American Kestrel wintering in California
During a recent survey for West Nile virus in wild birds around the Sonny Bono Salton Sea National Wildlife Refuge, Imperial County, California (Dusek et al. 2010), we captured a female American Kestrel (Falco sparverius) with a severe bill deformity (Figure 1). The kestrel was captured on 9 March 2006, at 08:45, approximately 0.25 km south of the intersection of Wiest and Lindsey roads (33° 08'AuthorsWilliam M. Iko, Robert J. DusekClimate change and wildlife health: direct and indirect effects
Climate change will have significant effects on the health of wildlife, domestic animals, and humans, according to scientists. The Intergovernmental Panel on Climate Change projects that unprecedented rates of climate change will result in increasing average global temperatures; rising sea levels; changing global precipitation patterns, including increasing amounts and variability; and increasingAuthorsErik K. Hofmeister, Gail Moede Rogall, Katherine Wesenberg, Rachel C. Abbott, Thierry M. Work, Krysten Schuler, Jonathan M. Sleeman, James WintonOccurrence of West Nile virus infection in raptors at the Salton Sea, California
We investigated the prevalence of West Nile virus (WNV)-neutralizing antibodies and infectious virus, and the occurrence of overwinter transmission in two raptor species during January and March 2006 at the Salton Sea, Imperial County, California. We captured 208 American Kestrels (Falco sparverius) (January, n=100; March, n=108) and 116 Burrowing Owls (Athene cunicularia) (January, n=52; March, nAuthorsRobert J. Dusek, William M. Iko, Erik K. HofmeisterOccurrence of avian Plasmodium and West Nile virus in culex species in Wisconsin
The occurrence of multiple pathogens in mosquitoes and birds could affect the dynamics of disease transmission. We collected adult Culex pipiens and Cx. restuans (Cx. pipiens/restuans hereafter) from sites in Wisconsin and tested them for West Nile virus (WNV) and for avian malaria (Plasmodium). Gravid Cx. pipiens/restuans were tested for WNV using a commercial immunoassay, the RAMP?? WNV test, anAuthorsT. Hughes, P. Irwin, E. Hofmeister, S.M. Paskewitz - News
Below are news stories associated with this project.
- FAQ
Below are FAQs associated related to vector-borne diseases.