The state public health lab in Concord reported its testing for West Nile Virus has identified the virus in 18 batches of mosquitoes from Manchester, Nashua and Salem, putting residents in those communities at an elevated risk of contracting the disease through the bite of an infected mosquito.

With eight batches previously identified by the Manchester Health Department, that means the total number of positive batches is now 26, nearly three times the number of positive batches last year.

Symptoms of the disease often appear four to 10 days after being bitten. If you or someone you know is experiencing flu-like symptoms, including fever and headache, you should contact your local medical provider.

The increase in batches of mosquitoes testing positive for West Nile Virus has prompted the Department of Health and Human Services to raise the risk level for arboviral diseases in those three communities.

“While this is our first announcement of West Nile Virus positives in New Hampshire this season, we have been hearing of positive test results from some of our neighboring states already,” said state epidemiologist Dr. Sharon Alroy-Preis.

“As with every year, this should serve as a reminder to people to take steps to prevent being bitten by mosquitoes,” she said.

“We encourage residents and visitors to enjoy the beautiful summer weather, but to do so safely. You can protect yourself and your family with a few simple steps, such as using effective mosquito repellant, wearing long sleeves and pants at dawn and dusk, when mosquitoes are most active, and removing standing water from around your house so mosquitoes do not have a place to breed,” she said.

The department issued these reminders about protection from mosquito bites and possible infection: Eliminate standing water and other mosquito-breeding locations; remove old tires; dispose of tin cans, plastic containers, ceramic pots, or other containers, including any that have become overgrown by aquatic vegetation; drill holes in the bottom of outside recycling containers; keep roof gutters clean and draining properly; clean and chlorinate swimming pools and hot tubs, or keep them empty and covered and keep covers free of standing water; aerate garden ponds or stock them with fish; turn over wheelbarrows and change water in birdbaths at least twice weekly; turn over plastic wading pools when not in use, and share these tips with your neighbors.

West Nile Virus was first identified in New Hampshire in August 2000. So far this season, the public health lab has tested 1,621 mosquito batches, two animals, and 10 people.

Last year, nine mosquito batches tested positive for West Nile Virus in New Hampshire and there were no positives for Eastern Equine Encephalitis.

Anyone with questions about WNV/EEE may call 1-866-273-6453 between 8 a.m. and 4:30 p.m. Monday through Friday. Other information about EEE and West Nile Virus is available on the DHHS website at www.dhhs.nh.gov and on the Centers for Disease Control and Prevention website at www.cdc.gov.

Arbovial Risk Assessment for New Hampshire