West Nile virus is a potentially serious disease. It has become a seasonal epidemic in the United States, it’s occurance peaks in August and September. The best way to protect yourself is to keep from being bitten.
Most commonly, it is transmitted by the Culex species mosquitoes, but the Aedes and Anopheles species transmit it as well. Most often, the mosquito bites an infected bird, and then transmits the West Nile virus to a human through it’s saliva. In very rare cases, it has been transmitted through blood transfusions, breast feeding and during pregnancy, from mother to child. Most often a mosquito bite is the cause of its spread. If you see a dead bird, DO NOT touch it. West Nile virus affects the central nervous system, but the severity of it’s symptoms varies widely.
Luckily, in about 80% of those infected, no symptoms appear, and they do not become ill.
Other people who have contracted West Nile virus experience mild symptoms, which are very similar to many flu symptoms. These people can experience nausea, body aches, chills, headaches, fever, swollen glands, and sometimes rashes. These symptoms are reported in about 20% of the cases. The aftermath of the infection can last a few days to a few weeks.
Significant symptoms from infection with the virus are not that common, but are quite serious. Only about 150 people infected with the virus each year have these serious symptoms. They include: high fever, muscle weakness, tremors, stupor, convulsions, vision loss, severe headaches, neck stiffness, coma, disorientation, numbness and paralysis. These symptoms can lead to neurological damage, and on very rare occasions, fatal encephalitis, or swelling of the brain. The symptoms, if they occur, will manifest about three to four days after the bite. In milder cases, rest and riding out the symptoms is usually enough. More severe cases need medical attention, including hospitalization.
For the most part, those at risk of the more severe symptoms are individuals over the age of 50. And, anyone who is outside often runs the risk of being bitten and contracting the virus.
In 2004, there have been a total of 1191 reported cases in the United States, and 30 fatalities. Since 1999, the Center for Disease Control has had cases from all states in the US except for Alaska, Hawaii, and Oregon. The disease is being reported in Europe, both West and Central Asia, Africa and North America. View a map of West Nile cases in the United States.
The disease was first reported in 1937 in the West Nile portion of Uganda. From there, it was found in Egypt in the 1950’s and recognized as a serious cause of fatal encephalitis from an outbreak in Israel in the late 1950’s. It did not appear in the United States until 1999, and then in both humans and horses. It has been found in other animals, such as dogs and cats, but they do not appear to become sick from the virus.
Keep in mind that it can be transmitted through other biting insects, such as ticks and no- see-ums.
The best way to avoid being stricken with the virus is to avoid being bitten by mosquitoes, especially in late summer and early fall. Avoid being outside around dusk and dawn, wear protective clothing and a good mosquito repellant, and keep your yard and home as free of breeding grounds as possible.