Louisiana tap water: Health officials cite 10 rare amoeba cases

Louisiana health authorities issued a warning on Thursday regarding the use of tap water for nasal irrigation and contact lens maintenance. The advisory follows the confirmation of ten Acanthamoeba infections in the state since 2024. State epidemiologist Theresa Sokol told residents in a press release that using the correct water source and maintaining strict hygiene can lower the risk of these rare but potentially deadly organisms.

The department identified eight of the ten cases as Acanthamoeba keratitis, an eye infection that frequently results in permanent vision loss. Seven of those patients wore contact lenses. Five individuals suffered permanent vision loss due to the infection. The remaining two cases involved non-keratitis infections, which affect the sinuses or brain. Both of those patients had weakened immune systems and had used tap water in nasal irrigation devices. One of the two patients died this year.

Officials have not released the name, age, sex, or residence of the deceased patient. The Louisiana Department of Health (LDH) stated that the infections are rare but can have devastating consequences. Sokol emphasized that the precautions are especially important for individuals with compromised immune systems.

According to the Centers for Disease Control and Prevention (CDC), Acanthamoeba is a free-living one-celled organism found in water, soil, and dust. It inhabits freshwater, still water, drinking water systems, and humidifiers. Most people encounter the amoeba without becoming ill. However, the organism can enter the body through cuts, open wounds, or the eyes. Inhalation is another route of infection.

The CDC notes that non-keratitis Acanthamoeba infections are rare in the United States, affecting between three and 12 people annually. A 2024 report cited by the agency indicates that 82 percent of these specific cases are fatal. In contrast, Acanthamoeba keratitis typically affects healthy individuals and is usually linked to contact lens wear. This type of infection generally does not spread to other parts of the body.

To reduce risk, the LDH recommends using distilled, sterile, or previously boiled and cooled water for nasal irrigation devices. Contact lens wearers should avoid using tap water to clean or store eyewear. Instead, they should use contact lens solution and proper cleaning methods. The department also advises removing contact lenses before swimming, showering, or using a hot tub.

The department issued a health advisory to Louisiana healthcare providers. The goal is to increase awareness and ensure early recognition of symptoms while reinforcing prevention recommendations.