West Nile virus has been found in a record number of mosquitoes in the New York City area, with at least two cases known to have occurred in humans. If you weren’t around for the last big West Nile panic about 20 years ago, you might be wondering just what this disease is and whether you should be worried about it.
What is West Nile virus?
The West Nile virus is transmitted by mosquitoes, and it can infect birds and some other animals, including horses, in addition to people. Most people who contract the virus won’t have any symptoms. About 20% will have a fever and flu-like symptoms, but in rare cases—one in every 150 people, the CDC estimates—the virus can cause more serious, neurological symptoms.
In those more severe cases, the brain or its membranes may become inflamed. Symptoms may include neck stiffness, confusion, weakness, convulsions, numbness, vision loss, or paralysis. One in 10 people with severe illness from West Nile may die.
Where is West Nile an issue?
The virus and the mosquitoes that carry it are present throughout the continental United States. The area with the greatest number of cases, based on historical data, occur in the Western half of the country, and are most common in the area that runs from North Dakota to Colorado.
Why is this happening now?
West Nile first made headlines in the early 2000’s, but it never really went away. The New York City Department of Health points out that increased temperatures make mosquitoes reproduce more quickly, which probably contributes to an increased spread of the disease. The weather in the southwestern U.S. has also been wetter than usual, which is good news for mosquitoes and bad news for us.
While the New York findings are in the news now, they’re not the only cases of West Nile. California, for example, has already had 12 human cases this year.
What should I do?
As with any mosquito-borne illness, the best way to protect yourself is to avoid getting bitten. A good bug spray that includes DEET or another EPA-registered pesticide (like picaridin) is key. You can also protect yourself by using window screens to keep mosquitoes out of your home, by wearing long sleeves and long pants where possible, and by using a fan to keep mosquitoes away when you’re chilling on the porch.
Mosquito control is also a good idea, in general. Mosquitoes breed in puddles of standing water, so if you have any buckets, flowerpots, birdbaths, potholes, or other places where water collects, consider dumping and cleaning them regularly, or treating them with larvicide (which kills the aquatic baby mosquitoes) if they cannot be dumped.