The Knox County Health Department has detected West Nile Virus in mosquitoes in Knox County, and is taking steps to reduce the population of mosquitoes by spraying for them.

The risk for West Nile virus is high in 10 cities and towns in Massachusetts, including Boston, public health officials say.

West Nile Virus has shown up in nearly every area around Massachusetts this summer, with 181 mosquito samples have testing positive for the virus so far, according to the state Department of Public Health.