2004's First West Nile Case?
Elderly Ohio Man May Be Year's First U.S. West Nile Virus Infection
April 14, 2004 -- A 79-year-old Ohio man may be the first human case of West Nile virus infection this year.
The Ohio Department of Health on April 9 reported that the man is a "probable case of West Nile virus." No other medical information is being released.
"We're waiting for confirmation from the CDC," Ohio Department of health spokesperson Kristopher Weiss tells WebMD.
The man lives in Scioto County in southern Ohio. Weiss says warm spring weather there has prompted mosquito activity.
Last year, Ohio reported 108 probable cases of West Nile virus infection: 84 cases of West Nile encephalitis/meningitis and 24 cases of West Nile fever. Of these 108 cases, Weiss says, 94 remain "probable."
West Nile Spread Through Mosquitoes
West Nile virus is carried by wild birds. Mosquitoes that bite infected birds can infect humans with the virus. It's uncommon, however, for human cases to appear so early in the mosquito season. Usually a period of "amplification" is needed as the pool of West-Nile-carrying mosquitoes builds up over time.
Typically, human West Nile virus infections in the U.S. peak in late summer and early fall.
Grant L. Campbell, MD, PhD, chief of epidemiology for the CDC's arbovirus disease branch in Ft. Collins, Colo., is in charge of tracking the West Nile virus in the U.S. He says it seems too early for human cases to be appearing as far north as Ohio.
"The Ohio report doesn't convince me yet that human cases have started to occur this year," Campbell tells WebMD.
Last year, the U.S. West Nile epidemic claimed 262 lives. There were 2,863 cases of brain or nervous-system infection with the virus, the most serious manifestation of West Nile virus infection. Overall, there were nearly 10,000 reported cases of West Nile infection.
However, only people who get ill are reported to the CDC. It's thought that eight out of 10 people infected with the virus never get any symptoms at all. However, West Nile disease is much more likely in people over the age of 50.