The West Nile Virus is a mosquito borne disease that occurs in many of the temperate and tropical regions of Africa, the Middle East, North America, Europe, Oceania and parts of Asia. The disease has an incubation period of about 2-15 days and it is after this time that the first symptoms occur. Symptoms vary between people, but a headache, fever, nausea/vomiting, muscle pain/weakness and other flu-like symptoms are relatively common. In about 1% of cases the disease causes very serious symptoms such as inflammation of the brain (meningitis and encephalitis) and it can also affect a number of organs. Let’s find out what causes this potentially life threatening disease.
What causes West Nile Virus?
As the name suggests, this disease is caused by a virus from a group of viruses known as flavivirus. The virus is spread to humans via infected female mosquitoes. The virus is transmitted while the mosquito draws blood from the host. This disease can also be spread between humans via infected blood, such as a blood transfusion, or in breast milk. Blood products are routinely screened for the virus in most countries where it is present. Ticks are also hosts of the disease, but current research shows that they do not commonly infect humans with the disease. The most common host for the disease are birds, which contribute to the spread of the disease when an uninfected mosquito bites an infected bird!
Did you know?
Other diseases caused by flaviviruses include yellow fever and dengue fever. This group of viruses was named after the yellow fever virus (“flavus” is the world for “yellow” in Latin).
There is no cure or vaccine for the virus and treatment relies on managing the symptoms. The disease can be prevented by protecting yourself against mosquito bites.
The West Nile Virus was first discovered in the United States in 1999 and it is now regularly found in many U.S. states.