People in 7 States Confirmed to Have Mosquito-Borne West Nile Virus: Know the Symptoms

The virus has progressed to severe illness in more than half the people who have been diagnosed with West Nile

The West Nile Virus has sickened people in 7 states so far — and some of the cases have progressed to severe disease.

Nine people in Arizona, Arkansas, Kansas, Maryland, Michigan, Mississippi and Tennessee have been diagnosed with the disease — but the virus has been found in non-humans (like mosquitoes and birds) in at least 18 states, the Centers for Disease Control reports.

That’s a troubling sign for the potential spread of the virus, as the CDC says, “People become infected with the virus when mosquitoes feed on infected birds and then bite people.”

Five of the nine people who have been diagnosed with West Nile have seen it progress to “neuroinvasive disease,” according to the CDC, which means they’ve developed illnesses like meningitis or encephalitis. 

Although the CDC says most people who get infected with West Nile will not get sick, those older than 60 or with certain medical conditions (like cancer, diabetes, or hypertension) are more likely to develop severe disease.

Those symptoms include “high fever, headache, neck stiffness, disorientation, coma, tremors, convulsions, muscle weakness, vision loss, numbness, and paralysis.”

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“We are seeing West Nile virus (WNV) activity a little earlier this year so it’s really important that everyone take steps to protect themselves and their families from mosquito bites,” Kate Fowlie, a press officer for the CDC, said in a statement, according to NBC News.

Related: Rebel Wilson Had Malaria After Waking Up with '100 Mosquito Bites on My Face'

“WNV tends to be unpredictable and varies from year to year so we don’t know specifically how this year will be compared to others.”

There is no cure or vaccine for West Nile; Instead, the CDC advises prevention instead.

Wear long sleeves and pants, the CDC says, and use an insect repellant with DEET, Picaridin oil, lemon eucalyptus, or para-menthane-diol — with the last two ingredients not recommended for children under 3 years of age.

And West Nile isn’t the only mosquito-borne illness on the rise; in June, the CDC warned about an increased risk of dengue fever in the U.S.

Related: Puerto Rico Declares Dengue Fever Epidemic amid Spike in Cases

In an earlier report on West Nile, the Environmental Protection Agency attributed the rise in mosquito populations to climate change.

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“Studies show that warmer temperatures associated with climate change can accelerate mosquito development, biting rates, and the incubation of the disease within a mosquito,” the EPA said.

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