West Nile disease is alive and kicking…
Despite a trend to become complacent about West Nile virus, it is still a disease that affects many Americans and does not have a cure, said James Sejvar from the Center of Disease Control (CDC). Sejvar’s speech Thursday afternoon was sponsored by the department of animal, dairy and veterinary sciences.
“A quick comment on treatment of the virus, very simple: there is none,” Sejvar said. “Basically everything including the kitchen sink has been thrown at the virus.”
The virus that is currently sweeping across the nation was first reported in New York in 1999, Sejvar said. Since then, there have been about 1.2 million people that have had some form of the infection, he said. About 4 percent, or 1,130 people, have died due to a West Nile virus infection since 1999 in the United States, he said. In Utah, approximately 292 people have become infected with about 3 percent of those cases being fatal, he said.
“I think the reality is, however, that over the past several years is that we’ve seen there are still quite a few surprises that this virus can throw at us,” Sejvar said.
The symptoms and manifestations of the virus vary greatly, Sejvar said. The symptoms can be any assortment of abrupt fever, headache, fatigue, nausea, vomiting, diarrhea to a transient rash, he said, and in some extreme cases, there can even be neurological damage such as confusion or comas and even death.
“In all reality the people that have this really feel lousy,” Sejvar said.
While the duration of the symptoms is unpredictable, there are studies that indicate that the infection can have serious effects for months and in most cases some symptoms persist for a year or more, Sejvar said.
The West Nile virus is passed and becomes more dangerous when the mosquitoes that carry the virus infect birds. Then, the virus becomes more potent and other mosquitoes bite the bird and become infected, passing the virus on, sometimes to humans and other mammals, Sejvar said.
While humans can become infected, there is no pattern as to who is at greater risk other than the elderly, Sevjar said. Children make up 5 percent of the West Nile virus infections and are no more likely to become infected than any other group, he said. Even those that were previously relatively healthy are just as likely as anyone else to become infected, he said.
“There are no reliable independent predictors of who’s at greater risk of experiencing these ongoing problems,” Sejvar said.
There are several ways the virus can affect humans, but about 80 percent of the people that become infected with the disease show little to no symptoms because of antibodies already in their systems, Sejva said. The mildest form of infection is West Nile flu, but there is also West Nile neuroinvasive disease which can be much more severe and more likely to be fatal, but is much less common, Sejvar said. Less than 1 percent of West Nile infections result in the neuroinvasive disease, he said
There are some vaccines that are currently being developed but it doesn’t appear to be cost effective to try and implement their wide-spread use, Sejvar said. It is more likely that they will be used in concentrated areas because that is how the virus spreads, from one center to the next, he said.
The virus first appeared in North America in New York. After spreading along the East coast, it migrated west and is much more prevalent in the western half of the United States now, he said. The reason it is no longer as common on the East Coast is not known, he said. However, some have speculated that the death of a large portion of the bird population on the East Coast is related to the disappearing of the virus in that area, he said.
To prevent becoming infected, Sejvar encouraged the audience to use mosquito repellent, wear long sleeved shirts and long pants, and avoid going outdoors at dusk and dawn when there are the most mosquitoes out.
-seth.bracken@aggiemail.usu.edu
LC