West Nile Outbreak on Track to Be Worst Ever
47 Deaths; Texas Especially Hard Hit
West Nile Symptoms continued...
Illness appears suddenly, says Petersen, who was infected in 2003.
"I was out for a jog, and in one mile I went from perfectly normal to the point where I could barely walk," he reports. "That is probably the norm."
And it's not usually a mild or brief illness.
"Those who get more ill with West Nile fever will be laid up in bed for days or a week, followed by a period of just feeling awful. And there can be a fatigue syndrome where people remain fatigued for weeks or months. It lasts longer than we used to think," Petersen said.
And these patients are lucky compared to those who get what the CDC calls "neuroinvasive disease." In about one in 150 people, West Nile virus infects the brain (encephalitis) or the spinal cord and connecting nerves (meningitis). So far this year, there have been 629 reported cases, with 58 cases of paralysis.
"The meningitis or encephalitis can cause paralysis that affects one or more limbs. It can also affect breathing. It is one of the more severe and dreaded complications," Petersen said. "With meningitis, symptoms include headache, stiff neck, eye pain, and fever. Encephalitis, infection of the brain itself, causes cognitive problems, where people can't think properly. It can also cause coma, along with all the symptoms of meningitis as well."
And there's another risk. Last month, Baylor University researchers reported that West Nile virus doesn't go away in some people. The virus hides in the kidneys. Over the course of years, it causes kidney disease that worsens over time.
People with neuroinvasive West Nile disease were most likely to have long-lasting infection and kidney damage. But this also happened to about 9% of those with mild or no symptoms.
Other laboratories have yet to confirm these findings. "But if they are true, they are of importance," Petersen said.
West Nile Virus: Who's at Risk?
Most serious cases of West Nile virus occur in people over age 50. This year, 61% of cases have been over 50, and 39% have been over 60. The elderly are at particularly high risk.