Human case of West Nile virus reported in McHenry County

Health officials have confirmed the first human case of West Nile virus in McHenry County.

Eight batches of mosquitoes, as one as one owl, have tested positive for the virus as of Sept. 6, officials said. Statewide, 19 human cases have been confirmed this year, including one death, according to the Illinois Department of Public Health.

The McHenry County Health Department said there are only two other known cases in the county in the last five years, in July 2022 and September 2023.

In humans, illness typically occurs two days to two weeks after the bite of an infected Culex mosquito, though most people exposed don’t develop symptoms, possibly because past exposure has given them immunity. The health department reports that about 20% of those infected experience mild fever along with other possible symptoms like headaches, body aches, joint pains, vomiting or a rash.

“Severe symptoms are very rare and include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness, and paralysis. Individuals 60 years of age or older or those with serious underlying health conditions, such as diabetes, kidney disease, hypertension, cancer, or who have received organ transplants are at greater risk for developing severe symptoms,” a health department news release states.

There is no vaccine or treatment for the virus. Mild symptoms can be relieved with rest, fluids, and over-the-counter medications for pain and fever. Seek medical attention if you or an individual you know develops severe symptoms.

For more on West Nile virus, go to mcdh.info or call (815) 334-4510.