The West Nile virus was found in seven mosquito samples collected last week in Oakdale and Mattituck, the Suffolk County health department said Friday.
The samples were collected Oct. 2 and 3 from unspecified locations in the two communities, health officials said.
It brings the county total this year to 177 positive samples in mosquitoes, 10 in birds and one human case, a Brookhaven man who was hospitalized with the virus but has recovered, health officials said.
The West Nile virus, first detected in birds and mosquito samples in Suffolk in 1999, is transmitted to humans through the bites of infected mosquitoes. Most people infected will experience mild or no symptoms, but others may develop severe symptoms, including fever, headache, convulsions, vision loss, numbness and paralysis.
"The past weeks of unseasonably warm weather seem to have prolonged the virus and mosquito activity," said Health Commissioner James Tomarken. "Therefore, residents should continue to do their best to reduce the mosquito population around their homes."
Residents can control mosquito breeding grounds -- stagnant water -- by disposing of cans, ceramic pots and other water-holding containers, the health department suggested. Ensure roof gutters drain properly and regularly change the water in birdbaths, officials said. Clear the water that collects on pool covers and the vegetation and debris from the edges of ponds, they said.
To avoid mosquito bites, people are advised to wear shoes and socks, long pants and long-sleeved shirts when outdoors for long periods of time or when mosquitoes are more active, between dusk and dawn.
To report mosquito problems or stagnant pools of water, call the Department of Public Works' vector control division at 631-852-4270.
For medical questions related to West Nile virus, call 631-854-0333.
For information on the virus, go to the Suffolk health department website at suffolkcountyny.gov/Departments/HealthServices.