2012 a bad year for West Nile virus

West Nile virus has been more active in 2012 than in any year since the disease was first detected, the CDC recently reported.

As of August 21, a total of 38 states had reported human cases of West Nile virus infection, with nine other states reporting it in birds or mosquitoes, according to a CDC telebriefing. The only states not reporting activity were Alaska, Hawaii and Vermont. A total of 1,118 cases in people, including 41 deaths, had been reported to CDC. Of these, 56% were classified as neuroinvasive disease and 44% were classified as non-neuroinvasive disease.

Approximately 75% of the cases came from five states: Texas, Mississippi, Louisiana, South Dakota and Oklahoma, with Texas being particularly hard-hit, CDC officials said. Reports appear to be still on the increase in most areas, including Texas. The peak of infections usually occurs in mid-August, but there is some delay in reporting. Officials were uncertain why the virus is more active this year, although they suggested the unusually mild winter, early spring and hot summer may have created favorable conditions.

There are no medications or vaccines for West Nile virus infection, a CDC press release noted. Patients with milder illnesses typically recover on their own, but patients with more severe cases often need to be hospitalized to receive supportive treatment, such as intravenous fluids, pain medication, and nursing care.

The experts urged the public to use insect repellents, wear long sleeves and pants during dawn and dusk, install or repair screens on windows and doors, use air-conditioning, and empty standing water from areas around the home to reduce the risk of infection. A viewpoint published by the Journal of the American Medical Association on Aug. 24 offered additional information about West Nile virus.