The Louisiana Department of Health and Hospitals (DHH) announced that its testing confirmed the presence of the Naegleria fowleri ameba in the St. John Water District 1 water system. This water system serves 12,577 people in the towns of Reserve, Garyville and Mt. Airy. There are no known cases of illness related to the ameba in St. John the Baptist Parish or elsewhere in the state currently.

Naegleria fowleri Life Cycle/CDC
Naegleria fowleri Life Cycle/CDC

The water system was sampled as part of DHH’s surveillance program that just launched earlier this month. During the ameba testing, DHH discovered the system was not in compliance with the State’s emergency rule, which requires water systems to maintain a minimum disinfectant residual level of 0.5 milligrams per liter throughout all of their distribution lines. This 0.5 mg/L level is known to control the Naegleria fowleri ameba.

DHH has issued an emergency order requiring St. John Water District 1 to perform a free-chlorine burn (maintain 1.0 mg/l of free chlorine throughout the system for 60 days) to kill the amebae within the water system.  The water will remain safe to drink during this time.  At the end of 60 days, DHH will sample the system again for presence of the ameba.  In previous cases in Louisiana, this action has been effective in controlling the ameba. The emergency order also requires the system to achieve and maintain compliance with the state’s minimum chlorine residual of 0.5 mg/l throughout their system.

St. John Water District 1 is the third water system in Louisiana to test positive for the ameba. Last year, testing by the Centers for Disease Control and Prevention (CDC) confirmed the presence of the ameba in the St. Bernard Parish Water System and DeSoto Parish Waterworks District No. 1.

“We are working closely with the water system and parish officials to ensure that the chlorine levels are increased to a level that will reduce the risk of exposure to the ameba,” said DHH Public Health Assistant Secretary J.T. Lane. “Water from St. John Water District 1 remains safe to drink; however, we do have guidance for residents on steps they can take to reduce their risk.”

“Residents in Reserve, Garyville and Mt. Airy are advised to take all recommended pre-cautions to avoid having water enter their nose,” said St. John the Baptist Parish President Natalie Robottom.  “The parish Utilities Department is taking immediate actions to fully chlorinate the water system and eliminate the threat.  As more information becomes available, it will be released to the public.”

“Families can take simple steps to protect themselves from exposure to this ameba, the most important being to avoid allowing water to go up your nose while bathing or swimming in a pool,” said Louisiana State Health Officer Jimmy Guidry. “It is important to remember that the water is safe to drink; the ameba cannot infect an individual through the stomach.”