The first human case of West Nile virus has appeared in Western New York, prompting public health officials to urge residents to minimize contact with mosquitoes.
The confirmed case in Erie County reported Thursday is the 11th identified this year in New York State, including one that was fatal.
The individual who contracted the virus here was hospitalized and recovered, officials reported.
The nation is experiencing one of the worst outbreaks ever of West Nile virus. So far this year, 1,118 cases of the disease in people, including 41 deaths, have been reported from 38 states to the federal Centers for Disease Control and Prevention.
This is the highest number of human cases of West Nile virus reported to the CDC since the virus was first detected in the United States in 1999. Approximately 75 percent of the cases have been reported from five states: Texas, Mississippi, Louisiana, South Dakota and Oklahoma. Nearly 50 percent of the cases have arisen in Texas
"The number of West Nile virus disease cases in people has risen dramatically in recent weeks and indicate that we're in the midst of one of the largest West Nile virus outbreaks ever seen in the United States," Dr. Lyle Petersen, director of the CDC Division of Vector-borne Infectious Diseases, said Wednesday in a teleconference.
Petersen said the peak of West Nile virus epidemics usually occurs in mid-August. However, because it takes a couple of weeks before people get sick and the virus is diagnosed by a doctor, officials expect more cases to show up through the end of September.
There were three confirmed cases of West Nile Virus in Erie County in 2011, although other cases may have occurred and not been identified. Prior to that, one has to go back to 2002 for the previous human case in the Buffalo area.
West Nile virus is usually spread by infected mosquitoes. About one in 150 people infected with West Nile virus become severely ill with symptoms that can include high fever, headache, disorientation and muscle weakness, according to the CDC. Milder flu-like symptoms occur in up to 20 percent of the people who become infected.
The other cases in 2012 in New York state have been confirmed in Nassau, Onondaga, Oswego and Suffolk counties, as well as in Manhattan, Queens and Staten Island in New York City.
"This is typically around the peak period when mosquito activity ramps up," said Scott Zimmerman, director of the Erie County public health laboratories.
It's not clear why this year is worse than previous years. One theory is that abnormally hot weather may promote outbreaks and increase the transmissibility of the virus, Petersen said
Zimmerman concurred that drought conditions over the summer likely aided, rather than hurt, mosquito populations.
"What happens, is that drought creates stagnant ponding where we don't usually see it, such as in streams, drainage ditches and storm sewers. The stagnant water is where you get mosquito breeding," he said.
To prevent spread of the disease, public health officials recommend that people use insect repellent, wear long sleeves and pants, and eliminate standing water in places that can serve as a mosquito breeding ground.
"This is a preventable disease," Zimmerman said.
