Overview
West Nile virus (WNV) is an infectious disease that first appeared in the United States in 1999. Infected mosquitoes spread the virus that causes it. The West Nile virus (WNV) is most often spread to humans from the bite of an infected mosquito. Mosquitoes become infected when they feed on infected birds. Infected mosquitoes can then spread WNV to humans and other animals when they bite. In a very small number of cases, WNV also has been spread through blood transfusions, organ transplants, breastfeeding and even during pregnancy from mother to baby. People over 50 years old and those with weakened immune systems due to HIV/AIDS, cancer, or organ transplants are most at risk for the infection. There are no specific vaccines or treatments for human WNV disease.
Symptoms
People who contract WNV usually have no symptoms or mild symptoms. However, symptoms may be very serious in some cases.
No Symptoms in Most People. – Approximately 80 percent of people (about 4 out of 5) who are infected with WNV will not show any symptoms at all.
Milder Symptoms in Some People. – Up to 20 percent of the people who become infected have symptoms such as fever, headache, and body aches, nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest, stomach and back. Symptoms can last for as short as a few days, though even healthy people have become sick for several weeks.
Serious Symptoms in a Few People. – About one in 150 people infected with WNV will develop severe illness. The severe symptoms can include high fever, headache, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness and paralysis. These symptoms may last several weeks, and neurological effects may be permanent. If WNV enters the brain, however, it can cause life- threatening encephalitis (inflammation of the brain) or meningitis (inflammation of the lining of the brain and spinal cord).
Preventing West Nile Virus
The easiest and best way to avoid WNV is to prevent mosquito bites:
- Use insect repellent
- Get rid of mosquito breeding sites by emptying standing water from flower pots, buckets or barrels
- Stay indoors between dusk and dawn, when mosquitoes are most active
- Use screens on windows to keep mosquitoes out
* For any questions you may have about mosquitos please call our environmental health department at 706-321-6170