First human case of West Nile virus of 2025 reported in Lake County, Illinois
The Lake County Health Department reported the first human case of West Nile virus in Lake County for the year.
The infected resident is in their 70s and became sick in early July, health officials confirmed in a written release.
According to the Lake County Health Department, nine out of 214 batches of mosquitoes have tested positive for West Nile virus so far this year.
This year's first case of West Nile virus in Illinois was reported in June. The Centers for Disease Control and Prevention confirmed that a person downstate, specifically in Southern Illinois, was hospitalized due to complications from West Nile.
West Nile virus peaks in late summer, usually from July through September, when the mosquito population is at its peak.
What is West Nile virus? How to prevent it.
West Nile virus is spread to people from infected mosquitoes, most commonly in the summer. Eight out of 10 people infected do not develop symptoms, according to the CDC.
The public is advised to do their best to protect themselves from mosquito bites, including using an EPA-registered insect repellent, wearing loose-fitting clothing, and, if possible, avoiding peak mosquito feeding times, typically around dusk and dawn.
"As the weather gets warmer, all Chicago residents are encouraged to Fight the Bite and protect themselves against mosquito bites so they can remain safe and healthy this summer," CDPH Commissioner Dr. Olusimbo Ige said.
It is also encouraged to check often overlooked places that may contain water, such as bird baths, water pails, and flower pots.
What are the symptoms of West Nile virus?
While most people infected with the virus do not feel sick, about one in five will develop a fever and flu-like symptoms. Other symptoms include body aches, vomiting, diarrhea, or rash.
Severe illness can occur in about one in 150 people and is most likely to occur in people over age 55 or with weakened immune systems.
The department said there are no specific medications to treat the virus in people. The best way to prevent getting sick is to prevent mosquito bites.
