Alarming West Nile Fever Risks Emerge. (Another Polio?)
Pickrell, J., Raloff, J., Science News
Having struck nearly 2,100 people and killed 98 in the United States so far this year, West Nile virus infection amounts to an epidemic. Now, medical workers have found poliolike symptoms in a few victims, and last week, federal officials said that blood transfusions appear to have infected some people.
The first U.S. cases of West Nile fever were reported in 1999 in New York. Since then, it's hit 35 other states. The disease is generally transmitted by mosquitoes.
Though flulike symptoms are most common, some severe cases progress to encephalitis, a potentially fatal swelling of the brain, occurs. Two reports to be published in the Oct. 17 New England Journal of Medicine link the virus to rare instances of long-term paralysis, a symptom that had shown up in birds, horses, and monkeys.
Discovery of West Nile patients with polio symptoms is a surprise, says Jonathan D. Glass of the Emory University School of Medicine in Atlanta, a coauthor of one of the reports. Poliolike paralysis is something "you've read about" but never see in the United States anymore, he says.
Poliomyelitis paralysis--caused by spinal cord damage--is historically associated with the poliovirus, though other viruses can also cause it, says Glass. Before polio vaccinations began in 1955, the disease was common in the United States.
Just as Glass' team realized this past summer that West Nile infection could yield paralysis, researchers and physicians at the Methodist Rehabilitation Center in Jackson, Miss. …