The state Department of Public Health announced Friday that mosquitoes trapped in Waterford on July 20 tested positive for West Nile virus, according to a news release.

This is the first occurrence of mosquitoes testing positive for West Nile virus in the state this year, according to a release from Ledge Light Health District.  

West Nile virus activity varies each year, according to the state Department of Health.

Last year, WNV-positive mosquitoes were trapped in 15 municipalities. Last year six state residents were identified with WNV infections from both Fairfield and New Haven counties.

"The first West Nile virus mosquitoes of the season have been identified," said Dr. Philip Armstrong, medical entomologist at the Connecticut Agricultural Experiment Station in a statement on Friday. "Early to mid-July is when we typically start to see an increase in infected mosquitoes, and this is a reminder for people to take steps to protect themselves from mosquito bites now through September."

Ledge Light recommends the following precautions to prevent insect bites:

• Minimize time outdoors at dusk and dawn.

• Be sure door and window screens are tight fitting and in good repair.

• Wear shoes, socks, long pants, and long-sleeved shirts. Clothing material should be tightly woven.

• Use mosquito netting when sleeping outdoors.

• Consider using mosquito repellent when it is necessary to be outdoors and always use it according to label instructions. The most effective repellents contain DEET or Picaridin. Oil of lemon eucalyptus is also effective for brief periods of exposure. When using DEET, use the lowest concentration effective for the time spent outdoors (for example, 6 percent lasts approximately 2 hours and 20 percent for 4 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 younger than 2 months.

The district said the following guidelines to minimize mosquitoes around the house include:

• 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, and cover pools when not in use.

• Use landscaping to eliminate areas where water can collect on your property.

According to the Centers for Disease Control and Prevention website, most people who contract the disease will present no symptoms. However, 1 in 5 people could develop a fever with other symptoms that may include headache, body aches, joint pains, vomiting, diarrhea, or rash.

Less than 1% of people who are infected will develop a serious neurologic illness such as encephalitis or meningitis, according to the CDC, and people age 60 or older are at the greatest risk of developing serious complications.

Additional resources for information on West Nile virus and mosquito management can be found at http://www.ct.gov/mosquito/site/default.asp.