West Nile and People

IT IS IMPORTANT THAT YOU UNDERSTAND THIS: there is no cure or vaccine for West Nile virus (WNV) in humans. Nationally in 2002, 4156 human cases of West Nile virus were reported, with 284 deaths. In Indiana, lab-identified human cases numbered 293, with 11 deaths. There is a real potential for serious illness, especially in those people 50 years of age and older. All 11 Hoosiers who died from the virus in 2002 were over 50.

There have been reports of human cases that were contracted via transfusions with whole blood and blood products, organ transplants, transplacental transmission, and breastfeeding. Currently, blood banks across the country are taking steps to protect the blood supply.

What are the symptoms of West Nile virus infection?

Most people who are infected with WNV will not have any type of illness. It is estimated that 20% of the people who become infected will develop West Nile fever with mild symptoms, including fever, headache and body aches, mental confusion, occasionally a skin rash on the trunk of the body, and swollen lymph glands. Symptoms of severe infection (West Nile encephalitis or meningitis) include headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis. It is estimated that 1 in 150 persons infected with WNV will develop a more severe form of the disease.

What is the incubation period in humans for West Nile encephalitis?

Usually 3 to 14 days.

How long do the symptoms last?

Symptoms of mild disease generally last a few days to a week or so. Symptoms of severe disease may last several weeks, although neurological effects may be permanent.

The number one goal is to prevent human illness. With no vaccine or cure for the West Nile virus, prevention is the key. See the "Prevention" link.