West Nile Virus Causing Serious
Nervous System Problems

By Jim Erickson
Rocky Mountain News

NEW ORLEANS -- West Nile virus appears to cause a higher rate of serious nervous system problems than researchers had thought, including Parkinson's-like movement disorders and temporary limb paralysis, a government neurologist reported Sunday.
Researchers had previously assumed that fewer than 1 percent of people bitten by infected mosquitoes develop severe central nervous system illnesses - a tiny tip of the West Nile iceberg, according to Dr. James Sejvar of the Centers for Disease Control and Prevention.
But a small West Nile study that started in August in St. Tammany Parish, north of New Orleans, suggests "the tip of that iceberg may be bigger than we thought," Sejvar said at the Fourth National Conference on West Nile Virus in the United States.
About 360 people, mostly federal, state and county public health workers, are attending the three-day meeting.
West Nile swept across the United States last summer, sickening about 4,000 people and killing 263. The virus was detected in Colorado in mid-August, and the state finished the year with 13 non-fatal human cases. The Colorado case count is expected to rise in 2003.
In the St. Tammany Parish study, CDC researchers worked with local physicians to find 42 people with fever of unknown origin or symptoms of encephalitis or meningitis, the two diseases most often associated with severe West Nile illness.
Sixteen of the 42 tested positive for West Nile and are being tracked in a study that will last at least a year, Sejvar said.
Fifteen of the 16 displayed tremors - sometimes severe enough to interfere with eating and grooming - during their illness. Ten patients experienced an involuntary jerking or twitching of the muscles.
In many cases, the tremors and twitching persisted more than five days, Sejvar said.Eleven of the 16 showed Parkinson's-like symptoms, including "cogwheel rigidity," which combines rigid muscles with tremors, balance problems, and slowed body movements.
Three of the 16 displayed temporary paralysis in a limb or on one side of the body.
"What appears to be going on is that the virus is affecting regions of the brain that direct and control motion," Sejvar said. The Louisiana study marks the first time many of these movement disorders have been tied to West Nile illness, he said.
Lyle Petersen, deputy director of the CDC lab in Fort Collins, called the findings "very important."
"They tell us something about the pathology of the disease and they give us some clue about what the long-term consequences of having West Nile virus infection might be."None of the 16 patients died. But in telephone interviews five to six months after their illness, most reported they were still experiencing persistent headaches, memory problems, fatigue and an inability to concentrate.
A much larger follow-up study is needed to flesh out the details of the findings uncovered in the St. Tammany pilot project, Sejvar said.,1299,DRMN_21_1734309,00.html



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