Louisiana’s Department of Health confirmed this week that brain-eating amoeba had been found in two water systems in the state.
Traces of Naegleria fowleri, a single-celled organism that can cause a rare, but fatal, brain disease, was found during routine water testing of Ouachita Parish’s North Monroe Water System and Terrebonne Parish’s Schriever Water System. Health officials assured residents that the tap water in these parishes are still safe to drink, but warned people to avoid getting any of it in their noses.
Naegleria fowleri infections occur when contaminated water enters the nose and the amoeba travels to the brain where it destroys brain tissue ― a disease known as primary amebic meningoencephalitis, or PAM.
According to the Centers for Disease Control and Prevention, early symptoms of PAM can be similar to those of bacterial meningitis, including headache, fever and nausea. As the disease progresses, stiff neck, seizures and hallucinations can occur. In most cases, death soon follows.
The fatality rate of the infection is over 97 percent in the United States, though it’s a rare affliction with only 40 cases reported in the country between 2007 and 2016.
Drinking contaminated tap water cannot lead to infection, stressed the CDC ― but using it for nasal irrigation or accidentally getting it into your nose can. Of the 40 people in the U.S. infected since 2007, four cases were caused by contaminated tap water. Nasal irrigation was the culprit for three infections; the fourth involved a person using a backyard slip-n-slide.
According to the CDC, the majority of infections in the U.S. have involved people swimming or diving in warm freshwater bodies like lakes and rivers.
The Louisiana health department issued a list of warnings this week for residents to avoid infection. This includes flushing out pipes by allowing shower taps and hoses to run for five minutes before use, and using “only boiled and cooled, distilled or sterile water for making sinus rinse solutions for neti pots or performing ritual ablutions.”
Louisiana health officials said on Thursday that they’ve told the two water systems to use the “free chlorine method” for 60 days to kill any remaining amoeba. Free chlorine is a strong disinfectant known to be effective at killing parasites.
Officials advised residents to continue following all precautions “until testing no longer confirms the presence of the amoeba in the water system. The water system will notify residents when that occurs,” the health department said.
Residents in the areas affected expressed concern about the infected water.
“It’s scary,” Terrebonne resident Bernadee Pitre told local WWL-TV this week. “[I’m] definitely going to be more careful about that.”
This article originally appeared on HuffPost.