HOLLAND, Mich. (WOOD) — Two people in Ottawa County and one in Kent County are in the hospital after testing positive for West Nile virus, according to health officials.

As of Thursday, the Ottawa County Department of Public Health said both people were in the hospital. Neither person recently traveled, suggesting they became ill from being bitten by an infected mosquito in West Michigan.

The same was true for the Kent County resident. The Kent County Health Department said the resident was likely bitten by a mosquito in the 49507 zip code, which includes Grand Rapids neighborhoods like Burton Heights and Garfield Park.

The Ottawa County Department of Public Health said this is the highest reported number of cases of West Nile virus in Ottawa County since 2018.

“They’re the first reported cases in 2023 and we have the most reported cases in the state of Michigan,” Ottawa County Department of Public Health spokesperson Alison Clark said.

In humans, West Nile virus symptoms include headaches, body aches, joint pain and fatigue. About 1 in 150 people infected can develop a serious case, including encephalitis or meningitis. Though it’s rare, West Nile virus can be fatal.

West Nile virus cases usually emerge in late summer and early fall. Health officials reminded people that the threat of mosquito-borne illnesses will continue until the first hard freeze of the season. Storm Team 8 says that usually happens around the first week of October.

“The best way to avoid West Nile virus illness is to not be bitten by an infected mosquito,” Clark said.

The state says that as of Sept. 15, six people in Michigan have contracted West Nile this year. Three other people contracted the mosquito-borne Jamestown Canyon virus.

—News 8’s Kyle Mitchell contributed to this report.