Louisiana has confirmed 10 infections from Acanthamoeba, a microscopic organism found in soil, dust and tap water, since 2024. Five people lost vision permanently and one died, the Louisiana Department of Health said Thursday. The department is telling residents to keep untreated tap water out of sinus rinses and never to clean or soak contact lenses in it.
Drinking tap water is not a risk for this infection, the department says. The danger comes when the organism reaches the eye or the nose.
What happened in Louisiana
Of the 10 cases from 2024 through 2026:
- Eight were Acanthamoeba keratitis, an eye infection. Seven of those patients wore contact lenses, and five were left with permanent vision loss.
- Two were found this year in people with weakened immune systems: one infection in the sinuses and one in the brain, which killed the patient. Both had used tap water in nasal rinsing devices.
The department notes that the tap water use does not prove the water caused those two infections. It has sent a health advisory to Louisiana doctors so they recognize the infections earlier.
CDC says most people will be exposed to the organism at some point, in soil, fresh water, swimming pools, hot tubs, humidifiers and drinking water systems, and most never get sick. The eye infection usually strikes healthy people, and most Americans who get it wear contacts. The brain infection is rare and almost always fatal.
If you use a neti pot or sinus rinse
Use only distilled or sterile water, or tap water that has been boiled and cooled. FDA's guidance on nasal rinsing says to boil tap water for 3 to 5 minutes, let it cool until lukewarm, and use it within 24 hours if you store it in a clean, closed container. Store-bought water should say "distilled" or "sterile" on the label. A filter built to trap infectious organisms also works, according to FDA.
According to FDA, stomach acid kills the small amounts of organisms in tap water you swallow, while in the nasal passages they can survive and cause infection. Louisiana also says not to clean rinse devices with untreated tap water.
If you wear contact lenses
About 45 million people in the U.S. wear contacts, according to CDC. Louisiana's advice for them:
- Never rinse or store lenses in tap water. Use a recommended contact lens solution and follow the cleaning and storage instructions.
- Take lenses out before swimming, showering or getting in a hot tub.
People who use CPAP machines and other devices that hold water should follow the manufacturer's directions for water and cleaning. People with weakened immune systems should ask their doctor about extra precautions with rinsing devices.
Symptoms to watch for
The eye infection can cause eye pain, redness, blurred vision, sensitivity to light, heavy tearing, or a feeling that something is stuck in the eye. Louisiana advises contact lens wearers with these symptoms to see an eye care professional promptly.
The other forms mostly affect people with weakened immune systems and are harder to spot. Seizures, confusion, headaches, weakness, fever, or sinus, vision or skin problems call for medical care quickly, and the department says patients should mention any recent sinus rinsing to their doctor.
