Year's first McHenry County West Nile mosquitoes detected
The first batch of mosquitoes testing positive for West Nile virus in McHenry County has health officials warning the public against the potentially lethal illness.
Officials discovered the West Nile mosquitoes on July 20 in the 60156 ZIP code.
The discovery is the first in McHenry County but only one of 272 positive West Nile test sites in the state this year. Jo Daviess County, in the northwest corner of the state, and Stephenson County, near the Wisconsin state line, are the only areas in Illinois yet to record a positive mosquito batch this year, according to the Illinois Department of Public Health.
Despite those numbers, Illinois has only one confirmed case of a human contracting the virus so far this year. That case involves a 67-year-old man in Will County who became ill at the end of June.
West Nile first appeared in Illinois in 2002. There were 884 human cases of West Nile in Illinois that year. Of those, a total of 67 died.
But since then, the number of human West Nile cases plummeted. There were about 155 human West Nile cases in Illinois last year. Only four counties - Cook, DuPage, Kane and Will - recorded five or more human infections.
McHenry County health officials said that doesn't mean West Nile is no longer a threat. Recent flooding will cause an increased number of mosquitoes in the area. The type of mosquito that transmits West Nile will rise in numbers if those floodwaters are left standing for long periods of time.
The health department will continue monitoring and testing mosquito traps for the virus. Residents should take protective measures against the virus until at least the first frost. Protective measures include using insect repellent and limiting skin exposure, particularly in the evening. Residents should empty outdoor containers of any standing water to prevent mosquito breeding.
The West Nile virus typically only carries mild health effects. Fever and headaches are common symptoms. But people 50 and older are at increased risk for serious illness stemming from West Nile including encephalitis, meningitis and death.
The McHenry County Health Department has a website where it posts the most up-to-date local information on West Nile. Information is also available by calling the health department at (815) 334-4585.