Progress 02/07/06 to 02/06/08
Outputs
Progress Report Objectives (from AD-416) This research is designed to develop fundamental and applied knowledge of the ecology, behavior, and control of mosquito vectors of West Nile (WN) virus and to characterize entomologic and environmental risk factors associated with the occurrence and distribution of WN virus in mosquitoes, humans, and animals. Approach (from AD-416) Discover, develop & evaluate biological control agents for mosquito vectors of West Nile Virus (WNV); develop new and improved trapping systems and attractant-enhanced trapping technology for the detection and control of mosquito vectors of WNV; characterize aspects of WNV etiology related to the distribution and prevalence of WNV antibodies in animals, possible vertebrate reservoirs for WNV and the role of other hematophagous arthropds as vectors. Significant Activities that Support Special Target Populations This project is related to Objective 3 of this in-house project: Investigate relationships between mosquito and fly biology, physiology, and behavior and disease transmission and surveillance. Research efforts by the Department of Entomology, (CAES) and the Mosquito and Fly Research Unit (MFRU) are directed to better understand the ecology of mosquitoes involved in West Nile (WN) virus transmission and develop new methods for mosquito surveillance and control. Studies were initiated on the horizontal and vertical transmission of WNV by Cx. salinarius. Cx. salinarius is considered an important bridge vector for WNV in northeastern United States. The risk of transmission of WNV to humans is associated with the density of infected vector mosquitoes in a given area. Current technology for estimating vector distribution and abundance is primarily based on CDC light trap collections, which provide only point data. In order to estimate mosquito abundance in areas not sampled by traps, logistic regression models were developed for five mosquito species implicated as the most likely vectors of WNV in Connecticut. Using data from 32 traps in Fairfield County from 2001 to 2003, the models were developed to predict high and low abundance for every 30x30m pixel in the County. They were then tested with an independent dataset from 16 traps in adjacent New Haven County. Environmental predictors of abundance were extracted from remotely sensed data. The best predictive models included non-forested areas for Cx. pipiens, surface water and distance to estuaries for Cx. salinarius, surface water and grasslands/agriculture for Aedes vexans and palustrine habitats for Cs. melanura. No significant predictors were found for Cx. restuans. In Fairfield County, the final models predicting high and low abundance correctly classified 75% of the traps for Cx. pipiens, 84.4% for Cx. salinarius, 84.4% for Ae. vexans and 93.8% for Cs. melanura. In New Haven County, the models correctly classified 81.3% of the traps for Cx. pipiens, 75% for Cx. salinarius, 62.5% for Ae. vexans and 81.3% for Cs. melanura. County-wide continuous surface maps of habitat suitability were generated for each species, which could contribute to future surveillance and intervention activities. Progress was monitored by e-mail communications, phone calls and periodic meetings.
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Progress 10/01/06 to 09/30/07
Outputs
Progress Report Objectives (from AD-416) This research is designed to develop fundamental and applied knowledge of the ecology, behavior, and control of mosquito vectors of West Nile (WN) virus and to characterize entomologic and environmental risk factors associated with the occurrence and distribution of WN virus in mosquitoes, humans, and animals. Approach (from AD-416) Discover, develop & evaluate biological control agents for mosquito vectors of West Nile Virus (WNV); develop new and improved trapping systems and attractant-enhanced trapping technology for the detection and control of mosquito vectors of WNV; characterize aspects of WNV etiology related to the distribution and prevalence of WNV antibodies in animals, possible vertebrate reservoirs for WNV and the role of other hematophagous arthropds as vectors. Significant Activities that Support Special Target Populations This report serves to document research conducted under a specific cooperative agreement between ARS and the Connecticut Agricultural Experiment Station (CAES), New Haven, CT and is based upon meetings, telephone calls, and site visits. Additional details of the research can be found in the report for the parent project 6615-320000-042-00D �Surveillance and Ecology of Mosquito, Biting, and Filth Breeding Insects. � Research efforts by the Department of Entomology, (CAES) and the Mosquito and Fly Research Unit (MFRU) are directed to better understand the ecology of mosquitoes involved in West Nile (WN) virus transmission and develop new methods for mosquito surveillance and control. Statewide mosquito trapping was conducted at 91 permanent trapping stations located in 72 municipalities. A total of 197,793 mosquitoes (12,661 pools) representing 34 species were trapped and tested for West Nile (WNV) and other mosquito transmitted viruses that cause human disease. A total of 219 isolations of WNV were made from 7 species of mosquitoes (Culex pipiens = 177, Culex restuans = 20, Culex salinarius = 16, Aedes vexans = 2, Culiseta melanura = 2, Ochlerotatus triseriatus = 1, and Coquillettidia perturbans = 1), collected at 25 sites in 5 counties (Fairfield, Hartford, Middlesex, New Haven, New London). Nine human cases of WNV, with one fatality, were documented in the state from residents of 7 towns with a cluster of activity in the greater New Haven area. The mosquito surveillance data were used to identify areas of high risk and to direct targeted pesticide spraying in New Haven and West Haven in the Fall of 2006 resulting in no further human cases. Other viruses isolated included: Jamestown Canyon (23), Trivittatus (7), Highlands J (5), Cache Valley (4), Eastern Equine Encephalitis (3), and Potosi (3).
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