Aug. 28, 2024 – Thirty-three states this year have had confirmed cases of West Nile virus, a mosquito-borne disease with no vaccine or treatment.
So far in 2024, there have been 289 cases of West Nile virus in the U.S., and two-thirds of them have been serious cases with neurological effects like brain swelling or, in rare instances, respiratory paralysis. The high-risk season for West Nile virus is just getting underway. Usually, the nation sees about 2,200 cases annually. Last year, the virus was linked to 182 deaths.
There is no vaccine for West Nile virus, and treatment for people infected consists only of supportive measures like receiving fluids, pain medicine, or help breathing.
Of all West Nile cases reported to the CDC from 1999 to 2023, 40% were among people age 60 or older.
Only about 20% of people develop symptoms, which commonly include fever, headache, body aches, vomiting, diarrhea, or a rash. Serious and potentially fatal illness affects about 1 in 150 people infected with the virus.
The CDC’s West Nile virus reporting season runs June to December, and the agency says there may be more cases due to reporting delays. Some cases aren’t due to active infections, but can be reported from detections in blood donations. And it’s possible that cases of diseases that affect the nervous system are higher because people are less likely to seek health care or suspect West Nile virus when they only have mild symptoms.
The CDC says the best way to prevent getting the virus is to reduce your risk of getting mosquito bites, such as by using insect repellent, wearing a long-sleeved shirt and pants, treating clothing and gear with repellent, and limiting mosquito populations by doing things like removing areas with standing water where they like to breed.