The US is seeing surging numbers of a virus that can cause life-threatening swelling in and around the brain and spinal cord.
And cases will continue to climb, as August has historically been the month where most cases appear.
This summer, the country saw the earliest start of the West Nile virus season — and the most cases in early summer since 2004.
On average over the last 22 years, only about 10 cases are reported by the end of June. This year, the CDC counted 48.
Cases have shot up since then. As of Wednesday, total cases in the US reached 143. As much as 69% of them had an infection that spread to their nervous system.
What does West Nile virus do to the body?
An estimated 80% of people with the virus won’t see symptoms or don’t have severe enough symptoms to go to a doctor.
Most people who do get symptoms get a sudden fever and may experience fatigue, headache, muscle aches, joint pain, a skin rash, vomiting or diarrhea.
About 1% of people experience neuroinvasive disease, or an infection that reaches the nervous system. This requires immediate hospitalization.
The virus could cause meningitis, or swelling of the membrane around the brain and spinal cord. People with meningitis get a sudden high fever, headache, stiff neck, and are sensitive to light. They might also be confused or struggle to stay awake and be nauseous or vomit.
People with similar symptoms might have a more severe condition — encephalitis, or swelling of the brain itself. Someone with encephalitis might also be agitated or get hallucinations, experience movement changes like twitching and tremors, and have trouble balancing.
Acute flaccid myelitis (AFM) might happen at the same time as meningitis or encephalitis. AFM affects the spinal cord, causing sudden muscle weakness in the arms or legs, loss of reflexes, facial drooping, and in severe cases, respiratory failure. This condition mainly affects young children.
People who catch West Nile virus are more likely to develop serious neuroinvasive disease if they’re older or are immunocompromised.
Which states are the virus in? When will West Nile virus season be over?
Twenty three states are reporting virus activity — the highest spread in a decade, the CDC said.
Arizona has the most cases, at 71. In Texas, 18 cases have been reported while California has 11.
Washington, Nevada, Utah, Wyoming, South Dakota, Colorado, Nebraska, New Mexico, Kansas, Oklahoma, Arkansas, Louisiana, Mississippi, Alabama, Georgia, Florida, Tennessee, Kentucky, Virginia and Pennsylvania have all reported less than five cases this year.
New York currently hasn’t reported any cases in humans. That said, mosquitos infected with the virus have been found across New York state and in NYC. As of July 25, the virus been detected in nearly twice as many Big Apple mosquito samples this summer compared to last year.
West Nile Virus starts to climb in May and peaks in August, which has historically spiked to triple the cases in July. It starts to decrease in September, but remains high until November.
How to protect yourself from West Nile virus
Wear the right clothes
- Keep mosquitoes away from exposed skin by wearing long-sleeved shirts, long pants, and socks.
- Tuck shirts into pants and pants into socks to cover gaps in your clothing where mosquitoes can get to your skin.
- Use head nets, long sleeves and long pants if you go to areas with high mosquito populations, such as salt marshes.
Use EPA-registered mosquito repellents and follow label directions and precautions closely.
Don’t let mosquitos in
- Replace your outdoor lights with yellow “bug” lights, which tend to attract fewer mosquitoes than ordinary lights.
- Use screens on windows and doors or air conditioning, if available, to keep mosquitoes outside.
- Cover all gaps in walls, doors, and windows to prevent mosquitoes from entering.
Stay on top of standing water
- Eliminate standing water in rain gutters, old tires, buckets, plastic covers, toys, or any other container where mosquitoes can breed.
- Empty and change the water in bird baths, fountains, wading pools, rain barrels, and potted plant trays at least once a week to destroy potential mosquito habitats.
- Drain or fill temporary pools of water with dirt.
- Keep swimming pool water treated and circulating.
