In addition to the eight human cases, three MI blood donors have had WNV detected in their blood.
According to the CDC, eight of 10 people infected with West Nile never show symptoms, while about 1 in 150 can develop a severe illness that affects the central nervous system, such as encephalitis or meningitis.
The human cases now confirmed increase the concern for transmission, officials said. They say the horses confirmed with the virus had not been vaccinated.
There is no evidence that people can get the virus from a horse that has the disease.
"Further cases are expected to be diagnosed in the coming period and West Nile virus infections are likely to occur in other geographical areas", it said.
"To date, there have been no human cases reported, no positive mosquito pools identified, and no positives identified by Canadian Blood Services through their screen program", Interior Health said in a release.
According to Interior Health, the risk of infection from handling birds is very low, but added people not use bare hands to handle wild birds, either dead or alive. Mosquitoes lay their larvae in standing water. Panama City Beach Mosquito Control, Bay County Mosquito Control and DOH-Bay continue surveillance and prevention efforts.
Avoid outdoor activities at dusk and dawn.
Maintain window and door screening to help keep mosquitoes outside. This is when mosquitoes that can carry the virus are most active. Although it may be hard to do when it's hot, wearing long-sleeves, long trousers and socks when outdoors will help keep mosquitoes away from your skin.
Some tips include: draining standing water to stop mosquitoes from multiplying and covering skin with clothes or repellent. DEET products should not be used on infants under two months of age and should be used in concentrations of 30% or less on older children.