THURSDAY, Aug. 22, 2002 (HealthDayNews) -- As the death toll from West Nile virus climbs, the government is providing more money to help states combat the mosquito-borne infection.
Health officials said today that 270 people in 12 states had developed confirmed West Nile illness as of yesterday morning. The death toll, which stood at 13 for this year, could now be 15 if two West Nile deaths reported today in Georgia are confirmed.
Much of the outbreak of late has occurred in the southern states of Mississippi and Louisiana, whose governor earlier this month declared a state of emergency. Nearly 150 people in Louisiana have tested positive for the disease.
Yesterday, U.S. Health and Human Services Secretary Tommy Thompson announced additional funding of $4 million to help states combat the virus. That brought the government's West Nile budget to more than $31 million this year, said Dr. Lyle Petersen, an infection expert at the U.S. Centers for Disease Control and Prevention.
West Nile spreads to humans through the bites of mosquitoes that have fed on infected birds or animals. While most people exposed to the pathogen develop no symptoms or only a mild flu-like malaise, in people with weakened immunity it can cause encephalitis and meningitis, potentially deadly inflammations of the lining of the brain and spinal cord.
Compared with previous years, West Nile has been more active across more states and is steadily moving West. So far, the virus has penetrated into Wyoming and Colorado, but nothing stands in its way of becoming a coast-to-coast infection. Cases "could potentially occur anywhere," Petersen said.
The average age of West Nile patients this year is 53 (ranging from 3 to 94), about 10 years younger than in the past. Petersen said that's probably because disease investigators have improved their surveillance of the outbreak and are now identifying milder cases of the illness.
"Older individuals have a higher tendency to get symptoms and more severe symptoms. That's the general pattern that's occurred in the last three years, and we think it's the same this year," Petersen said.
For every one person with encephalitis or meningitis, officials estimate that roughly 150 more were infected with the virus but didn't develop such severe symptoms. That would bring the total exposure this year to more than 40,000.
In Africa, where the virus is endemic, the pattern of cases seems to be opposite from the United States. There, young children typically develop symptoms of the infection, yet older people rarely fall ill with the disease, Petersen said. That suggests, but does not prove, a single infection leaves lasting immunity to the virus, as is the case with related pathogens like yellow fever and Japanese encephalitis.
West Nile infection has no vaccine or treatment, although researchers are hard at work trying to develop both. This week, the U.S. Food and Drug Administration approved a clinical trial with the drug alpha-interferon to treat people with symptoms. Alpha-interferon, which is sold as Intron A by Schering-Plough, is already used to treat hepatitis C and St. Louis encephalitis, a viral infection quite similar to West Nile.
Dr. James Rahal, an infectious disease specialist at New York Hospital Queens, is running the nationwide interferon study, slated to include 40 patients age 50 and up hospitalized with the infection. Younger people with encephalitis won't be excluded from the study, which has yet to get underway.
Doctors are now waiting for patients, Rahal said, who don't seem to be in short supply these days. However, he said some may have trouble with the idea of being "randomized"--that is, assigned to a group that receives sham therapy. Half of the group will be assigned to receive a placebo.
Rahal said he "wouldn't do the study" if he didn't think there was reason for optimism. But he said he's "certainly not fooling myself" that he knows if the drug will work.
Meanwhile, the best way to deal with West Nile is to avoid the mosquitoes that carry it, officials said. That means wearing protective clothing and bug repellent, preferably with the chemical DEET. The CDC also recommends that people stay indoors during the prime mosquito biting times of dawn and dusk.
What To Do
For the latest CDC word on West Nile virus, visit the agency's web site, or this site from Cornell University's Center for the Environment.
