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ASSOCIATIONS BETWEEN TWO MOSQUITO POPULATIONS AND WEST NILE VIRUS IN HARRIS COUNTY, TEXAS, 2003–06
1
| DENNETT, JAMES A. | 2007 |
KeywordsWest Nile virus, Culex quinquefasciatus, Aedes albopictus, gravid trap, minimum infection rate, Cyanocitta cristata, blue jay, blood meal analysis, WNV AbstractAssociations between Culex quinquefasciatus, Aedes albopictus and West Nile virus (WNV) activity, temperature, and rainfall in Harris County, Texas 2003–06 are discussed. Human cases were highly correlated to Cx. quinquefasciatus (r = 0.87) and Ae. albopictus (r = 0.78) pools, blue jays (r = 0.83), and Ae. albopictus collected (r = 0.71), but not Cx. quinquefasciatus collected (r = 0.45). Human cases were associated with temperature (r = 0.71), not rainfall (r = 0.29), whereas temperature correlated with Ae. albopictus and Cx. quinquefasciatus collections (r = 0.88 and 0.70, respectively) and Cx. quinquefasciatus pools (r = 0.75), but not Ae. albopictus pools (r = 0.55). Both species (collections and pools) and blue jays were weakly correlated (r ≤ 0.41) with rainfall, but blue jays were better correlated with Cx. quinquefasciatus pools (r = 0.87), compared with Ae. albopictus pools (r = 0.67), Ae. albopictus collections (r = 0.69), and Cx. quinquefasciatus collections (r = 0.46). Peak minimum infection rate for Cx. quinquefasciatus (4.55), and Ae. albopictus (4.41) was in August with highest human cases (17.87), blue jays (55.58), and temperature (29.01°C). Between both species, blood meal analysis indicated 68.18% of Cx. quinquefasciatus mammalian hosts were dog, while 22.72% were human, whereas Ae. albopictus had higher human (44.44%) but fewer dog hosts (22.22%). Ten bird species were identified as hosts for Cx. quinquefasciatus, with northern cardinal and blue jay representing 26.66% and 20.00%, respectively. No bird feeding activity was observed in Ae. albopictus. The earliest and latest human blood meal occurred in May (Ae. albopictus) and November (Cx. quinquefasciatus); 66.66% of human host identifications between both species occurred in October–November, after the seasonal human case peak. Based upon our data, WNV activity in both mosquito species warrants further investigation of their individual roles in WNV ecology within this region. AuthorsTesh, Robert B., Siirin, Marina, Randle, Yvonne, Guzman, Hilda, Wuithiranyagool, Taweesak, Bueno, Rudy, PARSONS, RAY E., DENNETT, JAMES A., BALA, ADILELKHIDIR, SARGENT, CHRISTOPHER B., HASSAN, HASSAN K., REYNA-NAVA, MARTIN and UNNASCH, THOMAS R. Year Published2007 PublicationJournal of the American Mosquito Control Association LocationsDOI10.2987/8756-971X(2007)23[264:ABTMPA]2.0.CO;2 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/17939505 |
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Efficacy of Resmethrin Aerosols Applied from the Road for Suppressing
Culex
Vectors of West Nile Virus
| Reddy, Michael R. | 2006 |
KeywordsWNV AbstractWe determined whether aerosol applications of resmethrin, delivered from the road, suppress the reproductive activity of Culex pipiens pipiens and Cx. restuans mosquitoes in suburban sites located near Boston. Oviposition implies a prior blood-feeding event and hence a potential West Nile virus (WNV) transmission-related event. Droplet size, rate of delivery and meteorological conditions were monitored. The target populations proved to be fully susceptible to the insecticide that was used. The roads in the test sites generally gave adequate opportunity for insecticidal coverage. We found that the aerosol plume may have failed to contact the target mosquitoes and conclude that such insecticidal aerosols, delivered from the road, may not effectively reduce the force of transmission of WNV in our test sites. AuthorsReddy, Michael R., Spielman, Andrew, Lepore, Timothy J., Henley, David, Kiszewski, Anthony E. and Reiter, Paul Year Published2006 PublicationVector-Borne and Zoonotic Diseases LocationsDOI10.1089/vbz.2006.6.117 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/16796509 |
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Fatal Encephalitis and Myocarditis in Young Domestic Geese (
Anser anser domesticus
) Caused by West Nile Virus
| Swayne, David E. | 2001 |
KeywordsWNV AbstractDuring 1999 and 2000, a disease outbreak of West Nile (WN) virus occurred in humans, horses, and wild and zoological birds in the northeastern USA. In our experiments, WN virus infection of young domestic geese (Anser anser domesticus) caused depression, weight loss, torticollis, opisthotonus, and death with accompanying encephalitis and myocarditis. Based on this experimental study and a field outbreak in Israel, WN virus is a disease threat to young goslings and viremia levels are potentially sufficient to infect mosquitoes and transmit WN virus to other animal species. AuthorsSwayne, David E., Beck, Joan R., Smith, Calandra S., Shieh, Wun-Ju and Zaki, Sharif R. Year Published2001 PublicationEmerging Infectious Diseases LocationsDOI10.3201/eid0704.010429 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/11585545 |
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Host-Feeding Patterns of
Culex
Mosquitoes in Relation to Trap Habitat
| Patrican, Lisa A. | 2007 |
KeywordsWNV AbstractMosquito feeding patterns identify vertebrate species potentially involved in the amplification of West Nile virus. In New York, northern cardinals (Cardinalis cardinalis) were the predominant hosts in most habitats. Crow (Corvus sp.) blood meals were most frequently identified from sewage treatment plant and storm water catch basin habitats. AuthorsUNNASCH, THOMAS R., Patrican, Lisa A., Hackett, Laura E., McGowan, Jay W. and Lee, Joon-Hak Year Published2007 PublicationEmerging Infectious Diseases LocationsDOI10.3201/eid1312.070275 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/18258048 |
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Importance of Vertical and Horizontal Transmission of West Nile Virus by
Culex pipiens
in the Northeastern United States
| Anderson, John F. | 2006 |
KeywordsWNV AbstractWest Nile virus (WNV) has become established in the northeastern United States, where mosquitoes are inactive during winter. There have been no documented studies to explain how this virus survives winter and reinitiates infection in spring. We report that WNV was vertically transmitted to 2 F1 female Culex pipiens from a naturally infected female collected in Stratford, Connecticut. One vertically infected F1 female, which was 168 days old, fed on a hamster that died 8 days later of West Nile disease. This suggests that WNV survives winter in unfed, vertically infected C. pipiens with amplification initiated in spring by horizontal transmission AuthorsAnderson, John F. and Main, Andy J. Year Published2006 PublicationThe Journal of Infectious Diseases LocationsDOI10.1086/508754 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/17083043 |
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Mosquito Surveillance for West Nile Virus in Connecticut, 2000: Isolation from
Culex pipiens
,
Cx. restuans
,
Cx. salinarius
, and
Cul | Andreadis, Theodore G. | 2001 |
KeywordsWNV AbstractFourteen isolations of West Nile (WN) virus were obtained from four mosquito species (Culex pipiens [5], Cx. restuans [4], Cx. salinarius [2], and Culiseta melanura [3]) in statewide surveillance conducted from June through October 2000. Most isolates were obtained from mosquitoes collected in densely populated residential locales in Fairfield and New Haven counties, where the highest rates of dead crow sightings were reported and where WN virus was detected in 1999. Minimum field infection rates per 1,000 mosquitoes ranged from 0.5 to 1.8 (county based) and from 1.3 to 76.9 (site specific). Cx. restuans appears to be important in initiating WN virus transmission among birds in early summer; Cx. pipiens appears to play a greater role in amplifying virus later in the season. Cs. melanura could be important in the circulation of WN virus among birds in sylvan environments; Cx. salinarius is a suspected vector of WN virus to humans and horses. AuthorsAndreadis, Theodore G., Anderson, John F. and Vossbrinck, Charles R. Year Published2001 PublicationEmerging Infectious Diseases LocationsDOI10.3201/eid0704.010413 |
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Spatio-temporal Analyses of West Nile Virus Transmission in
Culex
Mosquitoes in Northern Illinois, USA, 2004
| Gu, Weidong | 2006 |
KeywordsWNV AbstractAfter a severe outbreak of West Nile virus (WNV) in Cook County, Illinois, in 2002, detections of WNV in mosquitoes were frequent across the state in the following years despite small numbers of human cases. We conducted a spatio-temporal analysis of Culex (subgenus Culex) mosquitoes collected in 2004 in three mosquito abatement districts (MAD) in Cook County by calculating monthly estimates of mosquito density, prevalence of infected mosquitoes, and exposure intensity, which in turn is a product of mosquito density and infection rates. Mosquito infections were detected early at three sites in late May and were widely detected throughout the three MADs in the summer with infection rates as high as 13 per 1000 in August. Exposure intensities were higher at sites adjacent to the Des Plaines River, especially in August and September. The aggregated pattern of WNV transmission along the river might be related to the existence of substantial forest preserves and wetlands that might produce ecological conditions favorable for mosquito proliferation and interactions between mosquitoes and birds. AuthorsGu, Weidong, Lampman, Richard, Krasavin, Nina, Berry, Robert and Novak, Robert Year Published2006 PublicationVector-Borne and Zoonotic Diseases LocationsDOI10.1089/vbz.2006.6.91 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/16584331 |
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Surveillance for West Nile Virus and Vaccination of Free-Ranging Island Scrub-Jays (
Aphelocoma insularis
) on Santa Cruz Island, California
| BOYCE, WALTER M. | 2011 |
KeywordsWNV AbstractAbstract Transmission of West Nile virus (WNV) on mainland California poses an ongoing threat to the island scrub-jay (ISSJ, Aphelocoma insularis), a species that occurs only on Santa Cruz Island, California, and whose total population numbers 750 migrating and resident birds on the island from 2006 to 2009 indicated that WNV had not become established by the end of 2009. Several species of competent mosquito vectors were collected at very low abundance on the island, including the important mainland vectors Culex tarsalis and Culex quinquefasciatus. However, the island was generally cooler than areas of mainland California that experienced intense WNV transmission, and these lower temperatures may have reduced the likelihood of WNV becoming established because they do not support efficient virus replication in mosquitoes. A vaccination program was initiated in 2008 to create a rescue population of ISSJ that would be more likely to survive a catastrophic outbreak. To further that goal, we recommend managers vaccinate >100 ISSJ each year as part of ongoing research and monitoring efforts. AuthorsBOYCE, WALTER M., Vickers, Winston, Morrison, Scott A., Sillett, T. Scott, Caldwell, Luke, Wheeler, Sarah S., Barker, Christopher M., Cummings, Robert and Reisen, William K. Year Published2011 PublicationVector-Borne and Zoonotic Diseases LocationsDOI10.1089/vbz.2010.0171 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/21438695 |
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VECTOR COMPETENCE OF CULISETA INCIDENS AND CULEX THRIAMBUS FOR WEST NILE VIRUS
1
| Reisen, William K. | 2006 |
KeywordsCuliseta incidens (Thomson), Culex thriambus Dyar, West Nile virus, California, vector competence, WNV AbstractThe vector competence of Culiseta incidens (Thomson) and Culex thriambus Dyar for West Nile virus (WNV) were compared to Cx. quinquefasciatus Say or Cx. tarsalis Coquillett and Cx. stigmatasoma Dyar collected concurrently in California. Culiseta incidens were less susceptible to oral infection than Cx. quinquefasciatus, but transmitted virus at a significantly higher rate, thereby yielding comparable population transmission rates. Culex thriambus was equally susceptible to oral infection and transmitted virus at rates comparable to Cx. tarsalis or Cx. stigmatosoma. A mammalian host selection pattern most likely precluded detection of natural infection in Cs. incidens, a fairly abundant peridomestic species. In contrast, an avian host selection pattern and efficient vector competence resulted in repeated detection of WNV in Cx. thriambus; however, limited abundance and restrictive riparian larval habitat requirements would seem to limit the involvement of Cx. thriambus in WNV epidemiology. AuthorsReisen, William K., Fang, Ying and Martinez, Vincent M. Year Published2006 PublicationJournal of the American Mosquito Control Association LocationsDOI10.2987/8756-971X(2006)22[662:VCOCIA]2.0.CO;2 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/17304934 |
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West Nile Virus Antibody Prevalence in Red-Winged Blackbirds (
Agelaius phoeniceus
) from North Dakota, USA (2003–2004)
| Sullivan, Heather | 2006 |
KeywordsWNV AbstractThis 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. AuthorsLinz, George, Clark, Larry, Sullivan, Heather and Salman, Mo Year Published2006 PublicationVector-Borne and Zoonotic Diseases LocationsDOI10.1089/vbz.2006.6.305 Additional Information:http://www.ncbi.nlm.nih.gov/pubmed/16989570 |
