A Louisiana resident has died this year from a rare brain infection caused by the amoeba Acanthamoeba, and state health officials are now urging residents to stop using tap water for nasal rinses and contact lenses. The Louisiana Department of Health (LDH) has identified 10 Acanthamoeba infections since 2024, including two serious cases this year in people who both reported rinsing their sinuses with tap water, according to FOX Weather.

The key limitation comes first — LDH said tap water could not be established as the source of either serious infection, so the state is not saying any public water system is contaminated. Its warning targets how water is used, not whether it is safe to drink.

That distinction matters in almost every home. Drinking treated tap water does not put people at risk, health officials said. The danger comes when water is pushed deep into the nasal passages or held against the eye, where an organism that is harmless in the stomach can reach tissue it was never meant to touch.

An Everyday Habit Behind the Most Serious Cases

Of the 10 Louisiana cases, eight were Acanthamoeba keratitis, an infection of the cornea. The other two, both identified in 2026, involved the sinuses and the brain, and the brain infection was fatal. Seven of the 10 patients wore contact lenses, and five of the eight keratitis patients suffered permanent vision loss, LDH said.

LDH issued its advisory to Louisiana health care providers on Thursday, Oct. 29, to promote early recognition of the infection and reinforce prevention, according to the Louisiana Illuminator. State epidemiologist Theresa Sokol framed the warning plainly. "Although these infections are rare, they can have devastating consequences," Sokol said.

The national numbers support that balance. A 2023 study cited in a CDC report found that non-keratitis Acanthamoeba infections total fewer than 12 cases a year in the United States, but 82% of those cases were fatal, the Illuminator reported. The odds of infection are very low; the outcome when it happens is not.

Treated Water Is Not Sterile Water

Acanthamoeba lives naturally in soil, lakes, rivers, seawater, and household plumbing, according to the CDC. It is a different organism from Naegleria fowleri, the so-called brain-eating amoeba linked to warm freshwater swimming. LDH separately confirmed a Naegleria case this summer tied to a north Louisiana lake.

U.S. tap water is treated to meet drinking-water standards, but it is not sterile. In a 2024 CDC study that first linked Acanthamoeba infections to nasal rinsing, researcher Dr. Julia Haston pointed to how common the organism is. "It's very likely that we're all exposed to Acanthamoeba all the time," Haston told the Associated Press. A 1990s Ohio study found the amoeba and similar organisms in more than half of tap water samples tested.

Public understanding lags behind the science. CDC officials, citing a 2021 survey, said about one-third of U.S. adults wrongly believe tap water is free of microorganisms, and nearly two-thirds think it is safe for rinsing sinuses. Those beliefs help explain why a routine allergy remedy shows up again and again in rare amoeba cases.

Contact Lens Wearers Carry Most of the Risk

The Louisiana numbers point to the eye, not the brain, as the more common threat. Keratitis can develop when contaminated water reaches lenses, cases, or the surface of the eye, which is why LDH tells wearers never to use tap water to clean or store lenses and to remove lenses before swimming, showering, or using a hot tub.

Symptoms include eye pain, redness, blurred vision, sensitivity to light, excessive tearing, and the feeling that something is stuck in the eye. LDH said wearers with those symptoms should promptly see an eye care professional. Early treatment can make the difference between recovery and lasting damage.

People with weakened immune systems face the greatest risk of the rare brain and sinus forms. LDH urges them to seek care quickly for seizures, confusion, headaches, weakness, fevers, or sinus, vision, or skin changes, and to tell providers about any recent nasal rinsing or other water exposure. CPAP machines and similar respiratory devices also deserve attention, since LDH recommends following manufacturer instructions for the water used to fill and clean them.

Safer Water Choices at Home

The fix is simple and inexpensive — for neti pots, squeeze bottles, and other nasal irrigation devices, LDH recommends distilled water, sterile water, or tap water that has been boiled and cooled. The CDC's sinus rinsing guidance says boiled water should be held at a rolling boil for 1 minute, or 3 minutes at elevations above 6,500 feet, then allowed to cool. Rinse devices should be cleaned and dried after each use.

For lenses, the CDC's contact lens guidance calls for using only fresh, recommended disinfecting solution, never topping off old solution and never rinsing cases with tap water. Households do not need to stop drinking, cooking with, or bathing in tap water, and buying home water tests for Acanthamoeba is not part of official guidance.

Cost is rarely a barrier. A gallon of distilled water typically costs a few dollars, and boiling water at home costs almost nothing. The bigger barrier is habit, especially for people who have used tap water in a neti pot for years without a problem.

LDH has not announced a source investigation result for the two serious 2026 cases, and it has not reported any new cases since the advisory. Residents with questions about their own water system can contact their utility, and anyone with symptoms should contact a doctor rather than wait. The takeaway is narrow but important: tap water is fine for drinking, but not for the sinuses or the eyes.

What Readers Want to Know

Is Louisiana tap water safe to drink? Yes. LDH said drinking tap water does not put people at risk for Acanthamoeba infection. The warning applies to nasal rinsing, contact lens care, and certain medical devices.

Did tap water cause the fatal Louisiana case? That has not been established. Both serious 2026 patients reported using tap water for nasal irrigation, but LDH said it could not confirm tap water as the source.

What water should I use in a neti pot? Use distilled water, sterile water, or tap water that has been boiled for at least 1 minute (3 minutes above 6,500 feet) and then cooled.

Who faces the greatest risk? Contact lens wearers account for most keratitis cases. People with weakened immune systems face the greatest risk of rare brain and sinus infections.

What symptoms should contact lens wearers watch for? Eye pain, redness, blurred vision, light sensitivity, excessive tearing, or the feeling that something is in the eye. LDH advises seeing an eye care professional promptly.

Is Acanthamoeba the same as the brain-eating amoeba? No. Naegleria fowleri is a different organism usually linked to warm freshwater swimming. Both are rare, and both can be dangerous when water enters the nose.