Published August 30, 2012
While the death toll from cases of the West Nile virus in the United States, currently 41, is alarming, most people exposed to it never develop symptoms, according to UB faculty member Tom Russo.
The most recent numbers for West Nile virus cases reported to the Centers for Disease Control and Prevention are 1,118. Only one case has been reported in Western New York, and the patient who was hospitalized with symptoms has been released.
“Approximately 80 percent of infected individuals will be asymptomatic,” says Russo, professor of medicine in the School of Medicine and Biomedical Sciences.
“About 20 percent will develop mild disease characterized by fever, headache and body aches,” he says. “Less than 1 percent will develop severe disease, manifested by neurologic symptoms such as high fever, stiff neck, muscle weakness or paralysis, stupor or coma and convulsions.
“People over the age of 50 are most vulnerable,” he continues. “If symptoms do develop, it is usually between three and 14 days after the mosquito bite.
“Although there is only one case in Western New York to date, data from the Erie County public health department have shown that the number of infected mosquitoes in the region is higher this year than in recent years. Therefore, prevention is critical,” he notes.
And UB infectious disease specialist Richard Lee points out that even though it is now late summer, it’s too early to assume there won’t be a spike in cases locally.
“August and September are ideal times to see an increase in West Nile virus because that’s when mosquitoes are at full strength. I would expect to see more cases in the region,” says Lee, also a professor of medicine in the medical school.
“I think the high incidence of West Nile in Texas is a regional phenomenon related to extraordinary heat and a lot of bad water management,” he says.
Since there is no treatment for West Nile virus, Russo says the best advice is to avoid mosquito bites by trying not to go outdoors from dusk to dawn when mosquitoes are most active.
“If you do have to go out, wear long sleeves and long pants, and do apply insect repellant,” he advises. “Also, make sure you have screens on windows and the screens do not have holes in order to prevent mosquitoes from entering your home.”
Mosquitoes breed in standing water, he explains, “so drain all standing water on your property, make sure that gutters and other structures are free of water and debris, drill a hole in tire swings to promote drainage and be sure to empty bird baths and kiddie pools.”
Lee adds that people should be especially careful on golf courses “where grass is regularly watered to keep it looking green and where there are also ponds.”
What would be particularly worrisome to Lee?
“I would get really worried if there began to be a lot of reports of dead birds in the area because birds are the principal reservoir for West Nile virus,” he says, noting that crows and bluebirds are particularly vulnerable.