How to protect yourself from West Nile virus
Mosquitoes thrive during warm weather, increasing the risk of West Nile virus, a potentially deadly disease that impacts thousands of people every year in the United States. Infectious disease expert Helmut Albrecht, MD, explained what you need to know, including who’s most at risk and how to protect yourself from West Nile virus.
What’s the risk of West Nile virus to the public?
Since 1999, small epidemics of West Nile virus have occurred in different parts of North America every couple of years, usually first found in birds. Mosquitoes feed on infected birds and then spread the virus to humans.
Most people have no symptoms at all. However, about one in five will have fever, headache, body aches, joint pain and vomiting. “Most people fully recover in a couple of days to a couple of weeks,” Dr. Albrecht said.
One in 150 people develop encephalitis or a brain infection, which is severe and can cause permanent damage to your brain or nervous system. One in about 2,000 get infected and die.
The most severe cases occur in the immunocompromised and elderly, especially those who are over 80. Pregnant people and children, however, have no significantly increased risk.
Can people who don’t have symptoms spread the virus?
Dr. Albrecht said the risk of catching West Nile virus through mosquitoes is much higher than through asymptomatic people. “There are billions of infected mosquitoes and a handful of asymptomatic infected humans, so we need to minimize contact with these mosquitoes,” he said. “The only human to human transmission we see is mother to baby transmission, but even that is extraordinarily rare. It still goes through the mosquito to transmit to the next person.”
How can you protect yourself from West Nile virus-carrying mosquitoes?
Typically, a local health department will inform the public when there’s an increased risk of the virus and spray insecticide in those areas. But there are additional ways you can protect yourself.
- Use insect repellent. Products with DEET and picaridin are effective and are safe for use in children.
- Wear long sleeved shirts and long pants. If you go into the woods or work in the yard, you can apply permethrin (an insecticide that kills or repels mosquitos) to your clothes.
- Use screens on windows. Make sure they’re tight fitting, maintained and do not have holes.
- Get rid of standing water. Mosquitoes need stagnant water to breed, so turn over, cover or throw out items that hold water. If that’s not possible, empty them or rinse them at least once a week. That includes tires, buckets, planters, toys, birdbaths, flowerpots – anything that holds even little amounts of water.
Dr. Albrecht said spraying for mosquitoes helps when it’s done over large areas. “It’s more effective when cities and counties spray insecticide as opposed to a single household. That’s not going to make much of a difference.”
What else can you do to prevent West Nile virus? Is there a vaccine?
There is not a human vaccine for West Nile virus. There are four licensed vaccines for use in horses, but there hasn’t been enough commercial support for human vaccines.
Dr. Albrecht said the best way to prevent an outbreak of West Nile virus is through surveillance testing. “We must make public health a priority. West Nile virus is a rare disease and hardly ever causes severe morbidity and mortality, but if you’re one of those severe cases, it’s certainly a tragedy.”
One way the public can help is by reporting or submitting dead birds to their local health department.
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