What FPs need to know about West Nile virus disease

Journal of Family Practice, Sept, 2003 by Eric Henley

* HOW TO USE PUBLIC HEALTH RESOURCES

Prevention of West Nile virus disease will require both clinical and public health efforts. A good surveillance system is vital, providing clinicians and the community with knowledge about disease activity in birds and humans.

* Local or state health departments must coordinate, investigate, and track reports of dead birds by community members.

* Clinicians must notify the health department about suspected infections in humans.

* By publicizing the results of an active surveillance program, the health department assists clinicians in identifying cases more quickly and helps motivate the community to take appropriate preventive measures.

"Advice from your doctor: How to prevent West Nile virus infection," page 712, may be photocopied for distribution to patients.

ADVICE FROM YOUR DOCTOR

What you can do to prevent West Nile virus infection

Here are practical steps you can take to avoid being infected with West Nile virus, and to help stop the spread of disease.

To prevent mosquito bites

* Use an insect repellant that contains DEET at concentrations less than 50% for adults and less than 10% for children.

* Wear long sleeves and socks when outdoors,

* Be particularly careful during evening and early morning hours, when mosquitoes are most active.

Mosquito-proof your home

* Drain standing water regularly to minimize mosquito breeding grounds.

* Install or repair screens on windows and doors.

Report dead birds to local health authorities so they can better monitor the activity of West Nile virus transmission.

A short history of West Nile virus disease

In late August 1999, an infectious disease specialist reported 2 patients with encephalitis at 1 hospital in Queens to the New York City Department of Health. An ensuing investigation revealed 6 additional cases at nearby hospitals. The illnesses were characterized by fever, severe muscle weakness (7 of 8 persons), and flaccid paralysis (4 of 8). Cerebrospinal fluid test results suggested viral infection.

So began the saga of human West Nile virus in the United States.

The virus was first isolated from a patient in Uganda, and is now distributed throughout Africa, the Middle East, parts of Europe, southwestern Asia, and Australia. Disease outbreaks in other parts of the world were infrequent until 1996.

West Nile virus is thought to have come to North America from Israel, but it is not clear how. Since 1999, the virus has spread rapidly throughout the US. Interestingly, the number of human cases reported annually was low (20-60) until 2002, when more than 4000 cases were reported. Only 9 continental states had avoided human cases of West Nile virus, and only 4 had reported no human or animal cases.

SOURCES

Centers for Disease Control and Prevention. West Nile virus Web page. Available at: www.cdc.gov/ncidod/dvbid/ westnile/index.htm. Accessed on August 19, 2003.

Nash D, Mostashari F, Fine A, et al. The outbreak of West Nile virus infection in the New York City area in 1999. N Engl J Med 2001; 344:1807-1814.