| Achieving Operational Hydrologic Monitoring of Mosquitoborne Disease | Shaman, Jeffrey | 2005 |
KeywordsWNV AbstractMosquitoes 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. AuthorsDay, Jonathan F. and Shaman, Jeffrey Year Published2005 PublicationEmerging Infectious Diseases LocationsDOI10.3201/eid1109.050340 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/16229760 |
| Detection of West Nile Viral RNA from an Overwintering Pool of Culex pipens pipiens (Diptera: Culicidae) in New Jersey, 2003 | Farajollahi, Ary | 2005 |
KeywordsWest Nile virus, Culex pipiens pipiens, overwintering, viral RNA detection, WNV AbstractIn total, 1,324 Culex pipiens pipiens L. female mosquitoes were collected at Ft. Hancock, Monmouth County, New Jersey, from January to March 2001–2003. Mosquitoes were held in an insectary at 27°C and a photoperiod of 16:8 (L:D) h for 6 to 21 d after which they were tested in 34 pools. West Nile viral RNA was detected in one pool by a TaqMan reverse transcription-polymerase chain reaction assay; however, infectious virus could not be isolated using either Vero cell plaque assay or C6/36 mosquito cells. Twenty females dissected in January and March 2003 confirmed ovarian diapause status. We suggest that the mode of infection in this pool of overwintering females may have been due to vertical (transgenerational) transmission. AuthorsNasci, Roger S., Godsey, Marvin S., Farajollahi, Ary, Crans, Wayne J., Bryant, Patricia, Wolf, Bruce, Burkhalter, Kristen L. and Aspen, Stephen E. Year Published2005 PublicationJournal of Medical Entomology LocationsDOI10.1603/0022-2585(2005)042[0490:DOWNVR]2.0.CO;2 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15962803 |
| West Nile Virus in Host-Seeking Mosquitoes within a Residential Neighborhood in Grand Forks, North Dakota | Bell, Jeffrey A. | 2005 |
KeywordsWNV AbstractWest Nile virus (WNV) was first recovered in North Dakota near the city of Grand Forks in June 2002. During 2002, 2003, and 2004, we collected mosquitoes from Grand Forks using Mosquito Magnet™ traps and tested them for WNV. The seasonal abundance, species composition, and reproductive status of female mosquitoes were correlated with local environmental temperature and state surveillance data on WNV to determine the factors affecting local transmission of WNV. Over 90% of the mosquitoes collected were Aedes vexans, Ochlerotatus dorsalis, and Culex tarsalis, but WNV was detected only in Cx. tarsalis. Average summertime temperatures and relative abundance of mosquitoes were highest in 2002 but no WNV-positive mosquitoes were detected until the following summer. In 2003, nulliparous Cx. tarsalis appeared in mid-June (first summer brood), and parous Cx. tarsalis appeared in mid-July. The first WNV-positive pool occurred 21 July, and minimum daily infections rates increased thereafter until 27 August. The minimum infection rate (MIR) for Cx. tarsalis during the season was 5.7 infected mosquitoes per 1,000 tested, with the highest infection rates occurring at the end of the season as Cx. tarsalis populations started to decline. Mid-to-late August was identified as the period of highest risk for being bitten by a WNV-infected mosquito in Grand Forks during 2003. In 2004, viral activity in Grand Forks was low, due to very cool temperatures throughout the summer. To examine the genetic diversity of the 2003 WNV isolates from Grand Forks, we sequenced a 366-nucleotide region of the capsid and premembrane gene. Thirteen (46%) of the 28 WNV isolates contained at least one nucleotide substitution when compared to the homologous region of the progenitor WN NY-99 strain, and seven of these 13 substitutions coded for amino acid changes. Thus, WNV is established in North Dakota, it appears to be evolving and it is vectored primarily by Cx. tarsalis. Vector-Borne Zoonotic Dis. 5, 373–382. AuthorsBell, Jeffrey A., Mickelson, Nathan J. and Vaughan, Jefferson A. Year Published2005 PublicationVector-Borne and Zoonotic Diseases LocationsDOI10.1089/vbz.2005.5.373 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/16417433 |
| Wintering of Neurotropic Velogenic Newcastle Disease Virus and West Nile Virus in Double-Crested Cormorants (Phalacrocorax auritus) from the Florida Keys | Allison, A. B. | 2005 |
KeywordsNewcastle disease virus, double-crested cormorant, fusion protein, West Nile virus, Florida, wintering grounds, reservoir, WNV AbstractDuring November 2002, six double-crested cormorants (DCCs; Phalacrocorax auritus) were found moribund in Big Pine Key, FL, exhibiting clinical signs indicative of neurologic disease. Postmortem diagnostic evaluations were performed on two adult birds. Virulent Newcastle disease virus (NDV) was isolated from a cloacal swab from cormorant 1. West Nile virus (WNV) was isolated from the brain and lung of cormorant 2. Nucleotide sequence analysis of a portion of the fusion (F) protein gene of the NDV cormorant isolate revealed it shared a 100% deduced amino acid identity with only two viruses: the 1992 epizootic cormorant isolate from Minnesota and the 1992 turkey isolate from North Dakota. The epidemiologic significance of the recognition of virulent NDV on cormorant wintering grounds during a nonepizootic period, in addition to the potential implications of the concurrent isolation of NDV and WNV from cormorants, is discussed. AuthorsAllison, A. B., Gottdenker, N. L. and Stallknecht, D. E. Year Published2005 PublicationAvian Diseases LocationsDOI10.1637/7278-091304R Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/16094838 |
| Serologic Survey of Select Infectious Diseases in Coyotes and Raccoons in Nebraska | Bischof, Richard | 2005 |
KeywordsCanine distemper virus, coyote, Francisella tularensis, Leptospira interrogans, Nebraska, raccoon, Rickettsia rickettsi, serology, West Nile virus, WNV AbstractTo obtain data about select zoonotic and other infectious diseases in free-ranging predators in five ecoregions in Nebraska, sera were collected from 67 coyotes (Canis la-trans) and 63 raccoons (Procyon lotor) from November 2002 through January 2003. For coyotes, antibodies were detected against canine distemper virus (CDV, 61%), Francisella tularensis (32%), Rickettsia rickettsi (13%), and flaviviruses (48%). None of the coyote sera had antibodies to Borrelia burgdorferi, Brucella canis, or six serovars of Leptospira interrogans. Because serologic cross-reactivity exists among flaviviruses, 14 sera from flavivirus-positive coyotes were also tested for St. Louis encephalitis virus (SLE) antibodies and two (14%) were positive, suggesting that up to 48% of coyotes tested had antibodies against West Nile virus (WNV). For raccoons, antibodies were detected against CDV (33%), F. tularensis (38%), and three serovars of L. interrogans (11%). AuthorsBischof, Richard and Rogers, Douglas G. Year Published2005 PublicationJournal of Wildlife Diseases LocationsDOI10.7589/0090-3558-41.4.787 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/16456169 |
| Rural Cases of Equine West Nile Virus Encephalomyelitis and the Normalized Difference Vegetation Index | Ward, Michael P. | 2005 |
KeywordsWNV AbstractData from an outbreak (August to October, 2002) of West Nile virus (WNV) encephalomyelitis in a population of horses located in northern Indiana was scanned for clusters in time and space. One significant (p = 0.04) cluster of case premises was detected, occurring between September 4 and 10 in the south-west part of the study area (85.70°N, 45.50°W). It included 10 case premises (3.67 case premises expected) within a radius of 2264 m. Image data were acquired by the Advanced Very High Resolution Radiometer (AVHRR) sensor onboard a National Oceanic and Atmospheric Administration polar-orbiting satellite. The Normalized Difference Vegetation Index (NDVI) was calculated from visible and near-infrared data of daily observations, which were composited to produce a weekly-1km2 resolution raster image product. During the epidemic, a significant (p < 0.01) decrease (0.025 per week) in estimated NDVI was observed at all case and control premise sites. The median estimated NDVI (0.659) for case premises within the cluster identified was significantly (p < 0.01) greater than the median estimated NDVI for other case (0.571) and control (0.596) premises during the same period. The difference in median estimated NDVI for case premises within this cluster, compared to cases not included in this cluster, was greatest (5.3% and 5.1%, respectively) at 1 and 5 weeks preceding occurrence of the cluster. The NDVI may be useful for identifying foci of WNV transmission. Vector-Borne Zoonotic Dis. 5, 181–188. AuthorsWard, Michael P., Ramsay, Bruce H. and Gallo, Kevin Year Published2005 PublicationVector-Borne and Zoonotic Diseases LocationsDOI10.1089/vbz.2005.5.181 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/16011435 |
| West Nile Virus Detection in Kidney, Cloacal, and Nasopharyngeal Specimens | Ohajuruka, Ojimadu A. | 2005 |
KeywordsWNV AbstractWe compared kidney tissue samples and cloacal and nasopharyngeal swab samples from field-collected dead crows and blue jays for West Nile virus surveillance. Compared to tissue samples, 35% more swab samples were false negative. Swab samples were usually positive only when the corresponding tissue sample was strongly positive. AuthorsOhajuruka, Ojimadu A., Berry, Richard L., Grimes, Sheila and Farkas, Susanne Year Published2005 PublicationEmerging Infectious Diseases LocationsDOI10.3201/eid1209.050016 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/16229775 |
| Culex restuans (Diptera: Culicidae) Relative Abundance and Vector Competence for West Nile Virus | Ebel, Gregory D. | 2005 |
KeywordsCulex pipiens, Culex restuans, West Nile virus, Flavivirus, transmission, WNV AbstractThe abundance and vector competence of Culex restuans Theobald and Culex pipiens L. were compared to determine the relative importance of these species as West Nile virus (WNV) vectors in the northeastern United States. Abundance was estimated from egg raft collections at 12 sites in Albany, Suffolk, and Richmond counties, New York, during July, August, and September 2002 and 2003. Cx. restuans was more abundant than Cx. pipiens in both urban and rural areas, comprising 86% of 1,623 egg rafts collected. Vector competence for WNV was estimated after feeding on an artificial bloodmeal and in vitro transmission assays. The vector competence of the two species for WNV was similar, but the dynamics of infection seems to be mosquito species dependent. These findings suggest an important role for Cx. restuans in WNV transmission cycles in New York. AuthorsEbel, Gregory D., Rochlin, Ilia, Longacker, Jennifer and Kramer, Laura D. Year Published2005 PublicationJournal of Medical Entomology LocationsDOI10.1603/0022-2585(2005)042[0838:CRDCRA]2.0.CO;2 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/16363169 |
| Surveillance of Above- and Below-Ground Mosquito Breeding Habitats in a Rural Midwestern Community: Baseline Data for Larvicidal Control Measures Against West Nile Virus Vectors | Kronenwetter-Koepel, T. A. | 2005 |
KeywordsMosquito control, Breeding, Environment, West Nile virus, Culex, WNV AbstractBackground Mosquitoes in the genus Culex are thought to play a major role as vectors in the transmission cycle of West Nile virus (WNV) and other arboviruses in the United States. Effective control of mosquitoes through larviciding and adulticiding is expensive for communities and should be guided by reliable surveillance data on the distribution of mosquito breeding habitats. However, few small to medium sized cities in rural areas of the midwestern United States have this type of baseline information available.
Objective During the summer of 2004, we investigated the characteristics of Culex and other mosquito-breeding habitats in a rural central Wisconsin community with a population of approximately 19,000. Such baseline information will aid in the development of rational strategies to control mosquito populations and prevent human exposure to WNV and other mosquito-transmitted viruses.
Methods Mosquito larvae were collected and identified weekly from 14 below-ground storm water catch basins and 10 above-ground standing water sites distributed throughout the community. Collection began June 4, 2004 and continued through September 24, 2004. For each collection site the primary and adjacent land use patterns were determined.
Results Over the study period, 1,244 larvae were collected from catch basins; 94% were Culex species. Breeding activity was first detected in early July. Peak breeding was observed during a period of several weeks when average daily temperatures were at the maximum observed and rainfall had declined. Organically enriched catch basins in low intensity urban sites adjacent to forests and wetlands were found to be more productive breeding habitats compared to catch basins having little organic debris located in isolated high intensity urban sites. Above-ground standing water sites produced 1,504 larvae; 66% of which were Culex species. Flood control ditches and permanent wetlands with stagnant water were most productive, while ditches with moving water were least productive habitats. Larvae were produced earlier in the season by above-ground sites than were produced by catch basins. However, larvae production was more variable in above-ground sites since half the sites became dry at some point during the study period.
Conclusion The observed differences in Culex larvae production based on the variables of habitat-type, temperature, and precipitation support the need for ongoing surveillance in communities to guide public health officials in planning for and prioritizing mosquito control efforts. AuthorsKronenwetter-Koepel, T. A., Meece, J. K., Miller, C. A. and Reed, K. D. Year Published2005 PublicationClinical Medicine & Research LocationsDOI10.3121/cmr.3.1.3 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/15962015 |
| Serologic Evidence of West Nile Virus Infection in Three Wild Raptor Populations | Stout, William E. | 2005 |
KeywordsWest Nile virus, passive maternal antibody transmission, Cooper's hawk, great horned owl, red-tailed hawk, WNV AbstractWe 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. AuthorsStout, William E., Cassini, Andrew G., Meece, Jennifer K., Papp, Joseph M., Rosenfield, Robert N. and Reed, Kurt D. Year Published2005 PublicationAvian Diseases LocationsDOI10.1637/7335-012805R1.1 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/16252490 |
