05/30/2019
State Mosquito Monitoring Program Begins Testing for Mosquito-Borne Viral Diseases
New Haven, CT - The State of Connecticut Mosquito Management Program today announced it is monitoring mosquitoes for the presence of viruses that can cause illness in people including West Nile virus (WNV) and eastern equine encephalitis virus (EEE). The mosquito trapping and testing program, coordinated by The Connecticut Agricultural Experiment Station (CAES), will begin June 3. First test results will be available the week of June 10.
"Each summer, we trap and test mosquitoes in locations throughout Connecticut to monitor the risk of mosquito-borne diseases throughout the state." said Dr. Philip Armstrong, Medical Entomologist at CAES. "West Nile virus reemerges every summer and occurs primarily in urban and suburban communities in the state with the highest levels of activity from July-September. EEE virus transmission, in contrast, is more unpredictable from year to year and occurs later in the season in rural communities in southeastern Connecticut."
“While we cannot predict how much activity we will see this year with either West Nile virus or EEE virus the relatively mild winter and wet spring have created conditions that favor high mosquito populations as we enter the season,” said Dr. Theodore Andreadis, Director, CAES. “Our state-supported program which began in 1997 provides an effective early warning system for timely detection of these mosquito-borne diseases and assessing human risk.”
“Mosquito-borne diseases such as West Nile virus infection can cause severe disease in people of any age. People who are over the age of 60 are at greater risk for serious symptoms and should take extra precautions to avoid being bitten by mosquitoes,” said Dr. Jocelyn Mullins, Department of Public Health veterinarian. “When you are outside enjoying the warm weather this summer, take steps to protect yourself from mosquito bites. Using insect repellent, wearing long pants and long sleeves while outside, and avoiding being outdoors during the hours of dusk and dawn are effective ways to help prevent being bitten.”
Last season, WNV emerged as significant health threat in Connecticut. CAES detected higher than normal levels of WNV-infected mosquitoes with a total of 393 positive mosquito samples collected from 65 sites located in 53 municipalities. The majority of WNV activity was detected in densely populated urban and suburban regions in Fairfield, Hartford and New Haven counties, consistent with prior years. Twenty-three human cases, with one fatality, were reported. Clinical syndromes included WNV fever, meningitis, and encephalitis. There were also two equine cases last year. The Department of Public Health investigates all potential human cases of WNV and EEE infection and veterinary cases are investigated by the Department of Agriculture. WNV occurs every summer in the Northeast and has become the main cause of mosquito-borne illness in this region since it was first introduced into the NYC area in 1999.
During 2018, EEE virus was identified in six mosquito pools collected from towns in New London and Windham counties. No human or domestic animal infections were reported. EEE is a rare illness in humans, and only a few cases are reported in the United States each year. Most cases occur in the Atlantic and Gulf Coast states. EEE is the most severe mosquito-transmitted disease in the United States with approximately 33 percent mortality and significant brain damage in most survivors. A Connecticut resident died of EEE infection in 2013.
The response to mosquito transmitted diseases in Connecticut is a collaborative inter-agency effort involving the Department of Energy and Environmental Protection (DEEP), The Connecticut Agricultural Experiment Station (CAES) the Department of Public Health (DPH), the Department of Agriculture and the Department of Pathobiology at the University of Connecticut (UCONN). These agencies are responsible for monitoring mosquito populations and the potential public health threat of mosquito-borne diseases.
The CAES maintains a network of 92 mosquito-trapping stations in 72 municipalities throughout the state. Mosquito traps are set Monday – Thursday nights at each site every ten days on a rotating basis and then twice a week after detection of virus. Mosquitoes are grouped (pooled) for testing according to species, collection site, and date. Positive findings are reported to local health departments and on the CAES website at https://portal.ct.gov/CAES/Mosquito-Testing/Introductory/State-of-Connecticut-Mosquito-Trapping-and-Arbovirus-Testing-Program.
For information on WNV and EEE, what can be done to prevent getting bitten by mosquitoes, the latest mosquito test results and human infections, visit the Connecticut Mosquito Management Program web site at https://portal.ct.gov/mosquito.