The Massachusetts Department of Public Health (MDPH) announced that West Nile Virus (WNV) has been detected in mosquitoes collected from Norfolk. In 2015, 4,527 mosquito samples were tested for WNV and 164 samples were positive in Massachusetts. Norfolk had no WNV positive mosquito samples identified in 2015. WNV is most commonly transmitted to humans by the bite of an infected mosquito. The mosquitoes that carry this virus are common throughout the state, and are found in urban as well as more rural areas. While WNV can infect people of all ages, people over the age of 50 are at higher risk for severe infection.