West Nile's Early Outbreak a Troubling Sign
Its impact so early this season has health officials concerned
MONDAY, Aug. 5, 2002 (HealthDayNews) -- This year's outbreak of West Nile virus appears to have hit early and hard, which has health officials concerned but not in full panic mode.
"We're a little concerned, because the cases are appearing a bit earlier in the year than they have in the past, and there's a suggestion that maybe some of the people with encephalitis syndrome are a bit younger. But it's too early to say for sure if there's any change in evolution or pattern of outbreaks," Dr. Julie Gerberding, director of the Centers for Disease Control and Prevention, said today.
So far, human cases have been found in three states -- Louisiana, Texas and Mississippi. Louisiana leads the list, with 58 serious illnesses and four deaths in the last week. Mississippi has 22 confirmed cases and Texas, eight. There will probably be more cases in these and other states as the season progresses, health officials say.
The virus has also been detected in mosquitoes, birds or horses in 33 states and the District of Columbia, including as far west as South Dakota. Some states, such as West Virginia and Minnesota, are seeing their first ever cases this year.
"This is something we're going to have to learn to live with, because the virus is very well established in the bird and mosquito population," Gerberding said. "Where mosquitoes go, this is going to be a problem."
And the whole country will eventually have to learn to live with it as the virus continues its inevitable push toward the West Coast.
"The westward expansion of West Nile is not a surprise to any of us in the public health community," said John Roehrig, chief of the CDC's arbovirus diseases branch in Fort Collins, Colo.
During the winter of 1999-2000, immediately after the virus first appeared in the United States in the New York City area, Roehrig and his colleagues canvassed sewers and other areas in New York City where mosquitoes typically hibernate to see if the virus was present -- and it was.
"We knew at that point that it was going to make it through the winter and continue being active in the next year," he said.
One development that has officials on alert is how early the virus appeared this year.
"In previous years, the bulk of human disease activity has occurred between mid-July and mid-September," said Dr. James Hughes, director of the CDC's National Center for Infectious Diseases. "The onset of the first case this year actually occurred in mid-June, so it's a month or so earlier than in the three previous years. We have more cases already than in any of three previous years, so this will obviously be a peak year."
Again, this is not a big surprise. "Given that the focus has shifted to the South and West, this really is not that surprising, given the differences in climate, in bird populations and mosquito population," Hughes says.
This year's victims may also be a tad younger than previous years, but officials stress that's it's really too early to know for sure.
In the past three years, most people who developed serious complications, such as encephalitis, were elderly or had underlying health problems, such as compromised immune systems due to cancer or HIV.
"Most of the people exposed don't get sick, though it doesn't mean we should take it easy," said Dr. Jordan Glaser, director of the division of infectious diseases at Staten Island University Hospital. Several people on Staten Island have been infected with West Nile virus in previous years.
About one in 200 people who are infected develop a serious illness such as encephalitis, says Dr. Susan McLellan, of the section of infectious diseases at Tulane University School of Medicine, and Tulane's School of Public Health and Tropical Medicine. About 20 out of 200 will feel lousy with flu-like symptoms for a little while.
Encephalitis, or swelling of the brain, from any cause is potentially fatal.
Wendy Station, 47, of Vancouver, Canada, survived a bout with the disease in 1999 that was a long-delayed complication from a bout of childhood chicken pox. But she suffered brain damage significant enough to leave her permanently disabled and unable to work outside the home.
"I have no stamina. I get tired really fast. I sleep a lot, and my memory is shot," says Station, the creator of a Web site, Encephalitis Global, for survivors of encephalitis.
Glaser says many survivors of West Nile encephalitis had memory problems six months after they had supposedly recovered.
There's no treatment for the virus, but patients with severe complications are hospitalized and given intravenous fluids.
"As far as we know, a person who has been infected once should develop immunity to the virus," McLellan says.
Meanwhile, the CDC stresses that the best way to combat the disease is by eliminating pools of standing water where mosquitoes breed (including flower pots in your backyard) and by spraying to kill the adult mosquito population. Also, you should wear insect repellant, preferably one containing DEET, when you go outside.
"You don't want to get West Nile, especially if you're an older person," Glaser says. "You shouldn't be out there at dusk getting exposed to mosquitoes."
Adds Hughes, "This experience is a reminder that we have become somewhat complacent in this country about mosquito-born disease, and we will not be able to remain complacent."
What To Do
For more information on West Nile virus, how it's spread and how you can protect yourself, visit Fight the Bite Louisiana, or the Centers for Disease Control and Prevention. Survivors of encephalitis can find support and information at Encephalitis Global.