Nothing ruins the site of a gorgeous outdoor hike or the smell of a mouthwatering barbeque like a pesky swarm of mosquitoes. Even one or two of the insects can send nature-lovers to seek cover—or coverage! But mosquitoes can be way worse than an outdoor annoyance: they can carry serious diseases like the West Nile virus.

West Nile can be transferred to humans when mosquitoes bite. Thousands of people across the U.S. are infected each year, and over 2,000 people have died from the virus since it was first detected 20 years ago.1

It’s important to know if the virus has invaded your state, and the signs and symptoms of an infection. With the right knowledge, you can protect yourself and seek care right away if you think you’ve been bitten by a disease-carrying mosquito.

What to watch out for with West Nile

West Nile is tricky, because 80 percent of infected humans don’t show any symptoms.1 If you’ve been exposed to a lot of mosquitoes where West Nile has been found, your risk of getting infected goes up: Be on the lookout for fever and headache, says Kyon Hood, MD, FAAP, president of Teladoc Health Physicians.

These serious symptoms, along with confusion or sudden weakness, are cause for concern.3 Some people also have fatigue, body aches, joint pains, vomiting, diarrhea, or rash.2

While mild signs of a West Nile infection generally go away on their own, the virus can lead to a serious—even fatal—illness, Dr. Hood warns. About one in five infected people develop a sickness that causes inflammation in their brain or spinal cord.3,4

In these cases patients may experience:3

  • high fever
  • severe headache
  • stiff neck
  • disorientation or confusion
  • stupor or coma
  • tremors or muscle jerking
  • seizures
  • partial paralysis or muscle weakness

If you or someone you love experiences any of these symptoms, seek medical attention right away.

The “where” and “when” of West Nile

West Nile virus is commonly found across the United States and also in Africa, Europe, the Middle East, and West Asia.5 So how do you know if West Nile is in your state?

In 2018, 49 states and the District of Columbia reported West Nile virus infections in people, birds, or mosquitoes, with 2,544 reported cases in humans.6 From 1999 to 2017, disease cases totaled 48,183, found in every state except Alaska.7 While we won’t know exactly when and where West Nile will hit in 2019, most states are affected each year.

Mosquito season usually starts in the summer, continuing through fall. This can be troublesome since during this timeframe, many of us enjoy outdoor activities. If you’ve been bitten by an infected mosquito, you may notice the symptoms anywhere between two days and two weeks afterward.

What you can do about West Nile

Unfortunately, there’s no West Nile virus vaccine for people. The best you can do is take steps to avoid exposure, protecting yourself from mosquito bites. Even when it’s warm out, cover your skin with pants and long-sleeved shirts. Try lightweight materials so you don’t get too hot. Clothing coverage may also double as summer sun protection! But the most active time for the insects is dawn and dusk, so try to avoid being outdoors during these times.

After you’ve geared up with appropriate clothes, apply insect repellent to any exposed areas, Dr. Hood advises. “Mosquito repellent sprays like DEET and picaridin are a safe and effective way for reducing the likelihood of bites and disease transmission,” he says. For children, apply DEET products with a concentration of 30 percent or less.8

Worried about West Nile?

If West Nile has been detected where you live, take proper precautions when spending time outside. Try to maintain a dry exterior to your home, since mosquitoes tend to thrive in moist, water-laden areas. If your neighborhood gets hit particularly badly by mosquitoes this season, local authorities may decide to spray insecticide to prevent the virus’s spread.

If you do experience West Nile virus symptoms after being exposed to mosquitoes, a doctor may recommend testing. A serious case would warrant hospitalization. Concerned? Reach out 24/7 to one of our U.S. board-certified physicians who can assess your condition and help you with next steps.



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