The Bear River Health Department reported two cases of West Nile virus in humans on Friday, following a report of one case in Salt Lake County on Thursday.

West Nile virus activity is on the rise in some northern California counties, according to the Sacramento-Yolo Mosquito and Vector Control District. Three dead birds and 13 mosquito samples tested positive for the virus on Aug. 13, “the highest number of positive results reported in a single day this year,” the agency said in a news release.

Idaho health officials encourage people to take steps to prevent mosquito bites while outdoors and on their properties.

Philadelphia's Health Department will spray for mosquitoes in West Fairmount to combat potential West Nile virus carriers. The treatment is set for August 19, dusk, with a rain date on August 20.

Health experts say a confirmed case of West Nile Virus is connected to someone who travelled outside of Manitoba, but that doesn't mean there won't be homegrown cases this summer.