Chicago reported three human cases of West Nile virus in the last month as city officials warn the risk of contracting the virus is "high," with more mosquitoes testing positive than usual.

The patients range from 40 to 80 years old and reside on the Northwest and South sides. The patients’ symptoms began in late July or early August, according to the Chicago Department of Public Health.

Lake County intensifies mosquito control efforts to combat West Nile virus, following increased numbers of infected mosquitoes in the area, and local health officials advise residents on protective measures.

A West Nile virus survivor shared the story of her harrowing journey with the brain infection she first thought was a stroke. “Within a matter of days I was in the hospital and I got to the point where I couldn’t walk” said Tonya Riske,

The risk of West Nile virus in Chicago is considered “high,” as health officials say the area is experiencing “a higher proportion of mosquitoes testing positive for West Nile virus than usual.”