Trouble is flowing from the faucets in Louisiana.
State health officials issued an urgent warning to residents this week after a microscopic organism commonly found in tap water was linked to five cases of permanent blindness and one death.
“Although these infections are rare, they can have devastating consequences,” state epidemiologist Theresa Sokol said in a press release.
Since 2024, authorities have identified 10 cases of Acanthamoeba-related illness across the state.
The microscopic amoeba is commonly found in soil, dust and water, including what’s coming out of the bathroom sink.
While most people will encounter the microscopic bug at some point without ever getting sick, an infection can have devastating consequences for those who do, according to the Centers for Disease Control and Prevention.
The amoeba can enter the body through cuts or open wounds, inhalation into the nose or lungs, or through the eyes — particularly when contact lenses come into contact with contaminated water.
Where it takes hold determines how dangerous it can be, with consequences ranging from painful eye problems to potentially fatal brain disease.
One of the most common conditions it causes is Acanthamoeba keratitis, which affects the cornea — the clear outer layer of the eye. The condition can afflict even otherwise healthy people and lead to permanent vision loss.
Of the 10 Louisiana cases reported over the past two years, eight involved this type of eye infection. Seven of those patients wore contact lenses, and five were left permanently blind.
Two other Louisiana patients developed particularly severe forms of the disease, one affecting the sinuses and the other the brain. The latter was ultimately fatal.
Both patients had weakened immune systems and reported using tap water in nasal irrigation devices, which are designed to flush out the sinuses.
State health officials said that while the reported use of tap water doesn’t establish it as the source of these infections, it underscores the importance of safe water practices.
“Using the right water for nasal rinsing, following proper contact lens hygiene and taking precautions with medical devices can help reduce the risk,” Sokol said.
Drinking tap water is not considered a risk for Acanthamoeba infection.
From blurry vision to deadly disease
The Cleveland Clinic estimates that roughly 1,500 cases of Acanthamoeba keratitis are diagnosed in the US each year.
Symptoms include eye pain, redness, blurred vision, sensitivity to light, excessive tearing and the uncomfortable feeling that something is stuck in the eye.
Doctors typically treat the condition with prescription antiseptic eye drops, such as chlorhexidine and polihexanide, which target the amoeba and help relieve pain and other symptoms.
But medication doesn’t always do the trick. About 40% of cases don’t respond adequately to eye drops alone and may require surgery.
The chances of a good outcome are much higher when treatment begins before the disease spreads beyond the second layer of the cornea — generally within three weeks of the first symptoms.
Acanthamoeba cases affecting other parts of the body are far rarer — but can be much more dangerous.
The CDC recorded 208 such cases across the US between 1955 and 2025, including 14 in New York. Nationwide, the number typically ranges from zero to 12 cases a year.
People with weakened immune systems are particularly vulnerable to these more serious forms of the disease, which can affect the skin, sinuses and brain.
Making matters worse, the symptoms aren’t always easy to recognize, and many patients are initially misdiagnosed.
Health officials urge anyone with a compromised immune system who develops seizures, confusion, headaches, weakness, fever, sinus problems, vision changes or unusual skin symptoms to seek medical attention immediately.
When caught early, cases affecting the skin and sinuses can often be treated. But the longer the amoeba has to spread to other parts of the body, the harder it becomes to fight.
Perhaps the most frightening complication is granulomatous amebic encephalitis, a rare condition in which the amoeba attacks the brain.
That disease is almost always fatal.
