On the heels of Mobile County’s second case of the year of West Nile virus, health authorities reported Friday that mosquitoes caught in traps have tested positive for the virus.

Allegheny County Health Department officials announced mosquitoes collected in certain parts of the county earlier this month tested positive for West Nile virus. Samples found to have the virus were taken July 8 from Wilkinsburg,

Two mosquito test samples taken from Hyde Park and West Roxbury have tested positive for West Nile Virus, the Boston Public Health Commission announced Friday. There currently aren’t any confirmed human cases, and the commission told Boston residents the risk of transmission is low. But it encouraged protective steps be taken.