The first human case of West Nile virus in DeKalb County was reported late last week, according to the DeKalb County Health Department. A 59-year-old man was diagnosed with the virus, which is typically mild in humans.
The last weeks of summer have seen an increase in both confirmed and suspected cases of West Nile.
“At least locally it is happening, but I don’t know about nationally,” said Christy Gerbitz, operations director at Oaken Acres Wildlife Center in rural Sycamore.
Gerbitz said that in recent weeks, people have brought in about a dozen raptors like Cooper’s hawks, red-tailed hawks, great horned owls and turkey vultures exhibiting classic symptoms of the virus – about four times the number of raptors received last year.
Gerbitz said the birds seem disoriented and weak, and sometimes suffer seizures and clenched talons. The birds typically die within hours or days of being brought to the center.
Oaken Acres does not have its birds tested for West Nile virus. The last confirmed local cases of the virus in birds occurred in July, when two crows tested by the health department tested positive.
“It does affect raptors and birds in that class, but more often we see it in crows, robins and blue jays,” said Greg Maurice, director of the environmental health division of the health department. Maurice said the health department has found the virus in mosquito traps. Birds are typically infected after being bitten by an infected mosquito.
In Illinois, there have been 68 human cases reported this year, two of them fatal, according to the Illinois Department of Public Health. That’s the most cases in one year since 2007, when there were 101 confirmed human cases. Eighty-two Illinois birds have tested positive for the virus.
Nationwide, there have been 1,993 human cases reported this year and 87 deaths.
Kane County has had three human cases this year, one of them fatal. Most people infected with the virus experience flu-like symptoms and recover within a few days. The virus is most dangerous to the elderly and to those with weakened immune systems.
This summer’s drought has contributed to the increase in West Nile cases.
“The drought has eliminated floodwater mosquitoes, which are very rarely infected with WNV,” said Jane Lux, public health administrator at the health department. “The extreme heat and dry weather actually favors the culex mosquito, the primary carrier of WNV, which breeds in street catch basins (storm drains) and similar locations.”
Maurice said that the best way to prevent infection is to avoid being bitten.
“This includes eliminating standing water from around your house and property where mosquitoes breed and hatch and using mosquito repellent when outside,” he said. Experts also recommend wearing long sleeves and pants from dusk to dawn, and repairing screens on windows and doors.
The threat of West Nile virus is eliminated after the year’s first hard frost kills the mosquito population.