NEW YORK (Reuters Health) - Mosquito-borne West Nile virus, which can cause mild flu-like symptoms but can sometimes be fatal, is already more widespread in the United States than it was last year, researchers report.
"We know that the virus has spread and will continue to spread," Dr. Lyle Peterson with the Centers for Disease Control and Prevention in Atlanta, told Reuters Health. "For all we can tell, nothing is going to stop it from spreading throughout the entire U.S.," he added.
The latest statistics on the spread of West Nile virus were published in the November 24th issue of the CDC journal Morbidity and Mortality Weekly Report.
According to the CDC, in 1999 the virus was detected in four states - Connecticut, Maryland, New Jersey and New York.
By 2000, however, viral activity in birds and/or mosquitoes was reported from 12 states - Connecticut, Delaware, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, Vermont, and Virginia, and the District of Columbia.
West Nile Virus first appeared in the continental US in New York City in September of last year. In rare cases, infection with the virus, which is transmitted through bites from infected mosquitoes, develops into an inflammation of the brain, called encephalitis and can be fatal.
"There's absolutely no way to predict what will happen next year," said Petersen. "One of the problems with WNV is that it is unpredictable."
"There may be more potential for humans to become infected in future years than currently," said Petersen, who advised that during the summer months people take precautions to avoid mosquito bites by wearing mosquito repellent, long sleeve shirts or pants and avoiding being outside at times around dusk or dawn when mosquitoes are more active.
He also suggested that people should try to eliminate mosquito breeding grounds on their own property. "Mosquitoes don't fly very far and so just by getting rid of mosquito breeding areas on your own property can do a lot to reduce your risk."
Ways to reduce the number of mosquitoes include: making sure gutters aren't clogged, making sure the screens are in good repair, and draining any sources of water in yards.