What Is West Nile Virus?

Answer:
West Nile Virus is a form of encephalitis. It

is an infection of the brain that is caused by a virus. The disease was first found in Uganda in 1937. The term “encephalitis” means inflammation of the brain. One of the main causes of encephalitis is viral and bacterial infections, including viral infections which are transmitted by mosquitoes.

West Nile virus was first found during an outbreak in New York in 1999. The Centers for Disease Control (CDC) estimates that there were 42,000 cases worldwide in 2006. The disease is sometimes referred to as West Nile fever or West Nile encephalitis.

West Nile virus has been found in many animals, including humans, birds, and other vertebrate animals in Africa, Eastern Europe, West Asia, and the Middle East. Prior to 1999, the disease had not been seen in the Western Hemisphere. The original source of the United States outbreak in 1999 is believed to have been the Middle East. The strain in New York was virtually identical to a strain found in a goose on an Israeli farm in 1998.

People become infected with the West Nile virus after being bitten by a mosquito that is infected with the West Nile virus. The mosquitoes become infected by feeding on birds that have become infected with the virus. The bird does not necessarily get sick. The birds are merely vectors, or an intermediary carrier of the virus that aid in the transmission of the virus.

The incubation period of the disease is generally five to fifteen days. One important thing to remember is that the West Nile virus is not contagious. It cannot be transmitted from person to person. Humans are referred to as a dead-end host for the virus. This means that humans can be infected, but our immune system keeps the virus from multiplying enough for it to be passed back to a mosquito and on to other new hosts. There is also no evidence that the virus can be passed by handling infected dead birds, although this should be avoided.

Symptoms of a mild infection include fever, headache, and body aches, which often include a skin rash and swollen lymph nodes. Severe infections are less common and they can include symptoms such as headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, occasional convulsions, paralysis, and death. Death rates are 5-15%, and are higher among the elderly.

The risk of infection is highest during mosquito season and does not end until freezing temperature begins. Most infections occur during the late Summer and early Fall. In southern climates, infection can occur year round. Although anyone can get the virus, the risk of severe infection is highest among those aged 50 or older.

Currently, there is no treatment for West Nile virus. Most of the therapies are directed toward the complications of the brain infection. There is no specific antibiotic or medicine for the infection, and there is no vaccine to prevent the virus.