State of Connecticut Mosquito Management Program

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08/17/2020

DPH Announces First Connecticut Human Case of West Nile Virus Infection in 2020

Residents Are Advised to Protect Themselves and their Children from Mosquito Bites

The Connecticut Department of Public Health (DPH) today is announcing that a Connecticut resident has tested positive for West Nile virus (WNV) infection. This is the first human case of WNV-associated illness identified in Connecticut in the 2020 season. The patient, who is between 40-49 years of age, became ill during the second week of July with West Nile fever, and is recovering. Laboratory tests confirmed the presence of antibodies to WNV. This person lives in Waterbury, but may have been exposed to WNV in the Newington/Wethersfield area.

“The identification of a Connecticut resident with West Nile virus associated illness emphasizes the need to take actions to prevent mosquito bites,” said DPH Acting Commissioner Dr. Diedre S. Gifford. “Using insect repellent, covering bare skin, and avoiding being outdoors during the hours of dusk and dawn are effective ways to help keep you from being bitten by mosquitoes.”

“We continue to have weather conditions that are favorable for the mosquitoes that transmit West Nile virus,” said Dr. Philip Armstrong, Medical Entomologist at the Connecticut Agricultural Experiment station (CAES). “These mosquitoes are most abundant in urban and suburban areas with dense human populations.”

West Nile virus is the most prevalent mosquito-borne disease in the U.S. and has been detected in Connecticut every year since1999. Last year, CAES detected WNV in 82 mosquito samples from 23 towns and one human case was reported. Before 2020, 158 cases of West Nile virus were reported in Connecticut, of which 4 were fatal. For information on WNV human cases in CT, select here.

Most people (8 out of 10) infected with WNV do not develop symptoms. About 1 in 5 people who are infected develop West Nile fever, an illness which includes a fever and other symptoms such as body aches, joint pain, headache, or a rash. About 1 out of 150 infected people develop a severe illness affecting the central nervous system. About 1 out of 10 cases of severe illness are fatal.

Tips for Reducing Mosquitoes Around Homes

Mosquitoes require water for reproduction. The following are measures that can help reduce mosquitoes:

  • Eliminate standing water suitable for mosquitoes. Dispose of water-holding containers, such as ceramic pots, used tires, and tire swings.
  • Drill holes in the bottom of containers such as those used for recycling.
  • Clean clogged roof gutters.
  • Turn over objects that may trap water when not in use, such as wading pools and wheelbarrows.
  • Change water in bird baths on a weekly basis.
  • Clean and chlorinate swimming pools. When pools are not in use, use pool covers and drain when necessary.

Tips for Avoiding Mosquito Bites When Outdoors

Mosquitoes require a blood meal for reproduction. The following are measures that can help reduce bites from mosquitoes that feed on people:

  • Minimize outdoor activities at dusk and dawn when mosquitoes are most active.
  • Wear shoes, socks, long pants, and long-sleeved shirts. Clothing material should be tightly woven and loose fitting.
  • Use mosquito netting when sleeping outdoors.
  • Consider the use of CDC-recommended mosquito repellents, containing DEET, picaridin, oil of lemon eucalyptus, IR3535, or 2-undecanone, and apply according to directions, when it is necessary to be outdoors.
  • When using DEET, use the lowest concentration effective for the time spent outdoors (for example, 6 percent lasts approximately two hours and 20 percent for four hours) and wash treated skin when returning indoors. Do not apply under clothing, to wounds or irritated skin, the hands of children, or to infants less than two months old.
  • Be sure door and window screens are tight fitting and in good repair to avoid mosquito bites when indoors.

The State of Connecticut Mosquito Management Program is a collaborative effort involving the Department of Energy & Environmental Protection, the Connecticut Agricultural Experiment Station, 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 87 municipalities throughout the state. Mosquito traps are set Monday through Thursday nights at each site every ten days on a rotating basis. 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.

For information on West Nile virus and how to prevent mosquito bites, visit the Connecticut Mosquito Management Program website