Louisiana health officials warn against amoeba infections from tap water

The Louisiana Department of Health is urging the public not to use tap water for their sinuses or contact lenses following a fatal Acanthamoeba infection this year, one of 10 infections in the state reported since 2024. 

Health officials did not say when or where the infected person died. It’s one of two “serious” infections identified this year, both in patients with weakened immune systems. 

The other eight infections were cases of Acanthamoeba keratitis, an eye infection that can cause permanent vision loss. Seven infections involved people who wore contact lenses, and five people lost their sight permanently, according to the health department.

Both persons with serious infections reported using tap water in nasal irrigation systems, but the health department said tap water has not been established as the source of the Acanthamoeba. The microbe can also been found in garden and agricultural soil, freshwater bodies, swimming pools and indoor systems such as heating and air conditioning units, and humidifiers, according to the Centers for Disease Control and Prevention.    

A 2023 study cited in a CDC report found that non-keratitis Acanthamoeba cases are extremely rare, totaling fewer than 12 a year in the United States. But 82% of those cases were fatal.  

Acanthamoeba is distinct from Naegleria fowleri, more commonly known as the brain-eating amoeba. Naegleria is found most often in warm freshwater lakes, ponds, rivers and canals. 

Lillian Smart, an 8-year-old from Ruston, died in August after being infected with Naegleria, which health officials said she contracted from swimming in a North Louisiana lake. At least five deaths in Louisiana have been attributed to Naegleria infections since 2011. 

The health department’s advisory Thursday on Acanthamoeba inflections stressed the need for the public to use distilled, sanitary or previously boiled water in neti pots and other sinus rinsing devices as well as in continuous positive airway pressure machines for sleep apnea. 

Tap water is also not suitable to clean or store contact lenses, which should be removed before swimming, showering or using a hot tub, health officials said. 

“Although these infections are rare, they can have devastating consequences,” state epidemiologist Theresa Sokol said in a news release. 

Officials also stressed that drinking tap water does not put a person at risk for contracting Acanthamoeba infections.