People going to the United States should take precaution against West Nile fever, a potentially deadly disease spreading in the country, the Shanghai Entry-Exit Inspection and Quarantine Bureau warned yesterday.

The mosquito-spread disease has killed four in the United States since July 20, according to the US Center for Disease Control and Prevention.

A total of 12 US states have reported 182 cases in humans, of which 74 came during the week of July 14-20. Most came from the western state of Arizona.

So far, no effective medicine or vaccine is available to fight the disease.

Fang yong, a spokesman for the local bureau, said: "We have taken action to ensure the disease won't enter the border."

The general Administration of Quality Supervision, Inspection and Quarantine issued an emergency notice on Tuesday, requiring close examinations nationwide on individual entry and exit and on commodities.

The bureau requires all incoming passengers from the United States to fill out a health report form and receive a body temperature check. Those suspected of infection will be sent to designated local hospitals for check.

Symptoms of West Nile fever include fever, headache and rash. The disease is likely to cause neuroinvasive diseases like cephalitis, myelitis, and even death to people who have weak immune ability.

(Shanghai Daily July 30. 2004)