On Sept. 5, the Board of Health was informed that three mosquitoes testing positive for the Eastern equine encephalitis (EEE) virus were found in Rochester.

The virus was initially detected in Rochester and Marion in mid August. All of the mosquitoes in Rochester were found in the northern part of town.

EEE is a rare but serious illness spread by the bite of an infected mosquito. While EEE can infect people of all ages, those who are younger than 15 years old or older than 50 have a greater risk of contracting the virus.

The illness can cause inflammation of the brain. According to the Centers for Disease Control and Prevention, the mortality rate is approximately 33 percent.

A town-wide spray was conducted at the end of last month. According to the Board of Health, local officials are working with the Plymouth County Mosquito Control Board to ensure that areas where mosquitoes are found have been sprayed.

To stay safe, health officials encourage residents to avoid being outside from dusk to dawn when mosquito activity is at a peak. Long-sleeve shirts, pants and socks should be worn outside and repellent with the ingredient DEET should be applied.

For more information, including all EEE positive results from 2014 and more tips to stay safe, visit www.mass.gov.dphj/mosquito.