West Nile Virus Is Just So Much More

West Nile Virus

Once just a tropical disease, West Nile Virus suddenly is just so much more importantsince 1999. That is when a case was diagnosed in New York City and the disease raced across the country, infecting more than 37,000 people between 1999 and 2012. About 1,500 people have died.

The disease is spread by infected mosquitoes. In rare cases, the disease might also be transmitted by blood transfusion or from mother to infant during pregnancy, delivery, or breastfeeding. One of the odd things about the West Nile Virus is that most people who get infected do not get sick. Only about one infected person in five actually becomes ill with symptoms including fever and aching joints.

A few people who do develop symptoms with West Nile Virus, less than one percent of all victims, develop more serious neurological illness such as encephalitis and meningitis. Symptoms of the more serious infection may include headache, high fever, stiffness in the neck, disorientation, coma, seizures, paralysis, and even death.

People who are over 50 years old or who already have some condition such as kidney disease, diabetes, and cancer are at greater risk for more severe infection. In addition, recovery from a severe infection can take several weeks to months and some effects may be permanent.

West Nile Virus also infects other animals including birds and horses. In a relatively rare event, the Utah Division of Wildlife Resources reported that the West Nile Virus caused the of death 27 bald eagles over that last few weeks. Apparently the eagles contracted the disease by consuming infected prey.

Right now, no effective vaccine or antiviral medication is available, although several vaccines and drugs are in development. When warm weather arrives, the best protection against West Nile Virus is largely a matter of just so much more prevention.

Experts stress the use of insect repellent and the advantage of covering as much skin as possible, especially in wooded areas. Around private homes, it is important to empty standing water frequently. That includes even small amounts of water in birdbaths and other small containers. In some areas, public mosquito eradication programs may be needed.

Finally, a newly released report indicates that the economic effects of the West Nile virus are considerably greater than previously reported. Earlier studies have focused on the cost of initial treatment and hospitalization.

The new study also considers the cost of extended care including medications, follow-up doctor visits, and re-hospitalizations, as well as the cost of long term loss of productivity. The new result is that the West Nile Virus cost this country about $778 million between 1999 and 2012.

Authors of the latest report expect that the new information will provide policy makers and the pharmaceutical industry information they need to allocate resources and make decisions about drug development.

Going forward, it seems reasonable to expect that infections will continue to spread and treatment costs will continue to rise. Preventing infections will require both personal and public mosquito control efforts and the development of new vaccines.

In every way, West Nile Virus is showing itself to be just so much more challenging and so much more expensive than expected.

By Sharon I. Fawley


CBS News
Centers for Disease Control
National Wildlife Health Center
NBC News
The American Journal of Tropical Medicine and Hygiene