Locally Trapped Mosquitoes Positive For West Nile
The Newtown Health District was notified by the state Department of Public Health on Tuesday, August 31, of a positive test result for West Nile virus from the mosquito trapping station in Newtown. The state has also isolated two people who have contracted the virus — the patients are residents of West Haven and Bridgeport.
West Nile virus is spread by infected culex species mosquitoes; such mosquitoes are common in Connecticut and in the northeast region, according to Newtown Health District Director Donna Culbert. Culbert told The Newtown Bee August 31 that she was expecting the state to announce that mosquitoes carrying West Nile virus were proliferating, and that possible human cases could result.
“I am not surprised by this news; we commonly see West Nile virus around this time of year,” the local health official said, adding that the summer, so far, has been rainy and warm, creating a favorable environment for breeding mosquitoes.
The state Department of Energy & Environmental Protection (DEEP)/Connecticut Agricultural Experiment Station (CAES) mosquito trapping and testing program includes a trapping station in Newtown. This is the first report of a mosquito from the Newtown station testing positive for West Nile this year.
The State of Connecticut Mosquito Management Program is a collaborative effort involving DEEP, CAES, the Department of Public Health, the Department of Agriculture, and the University of Connecticut Department of Pathobiology and Veterinary Science. These agencies are responsible for monitoring the potential public health threat of mosquito-borne diseases.
The CAES maintains a network of 108 mosquito-trapping stations in 88 municipalities throughout the state. Mosquito traps are set Monday through 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 portal.ct.gov/caes/mosquito-testing/introductory/state-of-connecticutmosquito-trapping-and-arbovirus-testing-program.
For information on mosquito-borne illnesses, what can be done to prevent getting bitten by mosquitoes, and the latest mosquito test results and human infection statistics, visit the Connecticut Mosquito Management Program website.
The most important thing residents can do is minimize their exposure to mosquitoes and mosquito bites: Use personal protection, wear long sleeves and pants, use insect repellent, and avoid being outdoors at dusk and dawn when mosquitoes are most active for feeding. Residents should also continue to eliminate standing water around their homes, check screens and repair them as necessary, and check for openings to their homes where insects could enter.
“Along with the ever-abundant tick population, it is important for residents to take precautions to avoid getting bitten by mosquitoes as well,” Culbert said. West Nile virus is the most common mosquito-borne disease in the United States and reemerges every summer in Connecticut.
Positive Human Cases
On August 31, the Connecticut Department of Public Health announced that two Connecticut residents have tested positive for West Nile virus infection. These are the first two cases of West Nile virus-associated illness identified in Connecticut this season.
The patients are between 70 and 79 years of age and became ill during the third week of August with meningitis and meningoencephalitis. Both are hospitalized and recovering. Laboratory tests confirmed the presence of antibodies to the virus.
“The identification of two Connecticut residents with West Nile virus-associated illness requiring hospitalization emphasizes the potential seriousness of this infection,” said Dr Deidre S. Gifford, senior advisor to the governor for Health and Human Services, and acting commissioner of the Department of Public Health. “As we approach the cooler weather and the holiday weekend, it is important to take precautions to avoid mosquito bites. Using insect repellent, covering bare skin, and avoiding being outdoors during the hours of dusk and dawn are effective ways to help keep from being bitten by mosquitoes.”
“We continue to have weather conditions that are favorable for the mosquitoes that transmit West Nile virus,” added Dr Philip Armstrong, medical entomologist at the CAES. “These mosquitoes are most abundant in urban and suburban areas with dense human populations. We anticipate continued risk for human infection until mosquito activity subsides in October.”
West Nile virus has been detected in Connecticut every year since 1999, and is the most prevalent mosquito-borne disease in the US. Last year, CAES detected the virus in 143 mosquito samples from 23 towns; eight human cases were reported.
Before 2021, 166 cases of West Nile virus were reported in Connecticut, of which four were fatal.
Most people (eight out of ten) infected with West Nile virus do not develop symptoms. About one in five people who are infected develop West Nile fever, an illness that includes a fever and other symptoms such as body aches, joint pain, headache, or a rash.
About one in 150 infected people develops a severe illness affecting the central nervous system. About one in ten cases of severe illness are fatal. People over the age of 60 are at highest risk of serious illness.
For more information about the West Nile virus, visit portal.ct.gov/dph/epidemiology-and-emerging-infections/west-nile-virus or cdc.gov/westnile/index.html.
Editor John Voket can be reached at firstname.lastname@example.org.