Feb 11, 2014 10:27 PM by AP
BATON ROUGE, La. (AP) - Water samples taken in late January from the St. Bernard Parish water system have tested negative for a rare amoeba that has killed three people in Louisiana since 2011, state health officials said Tuesday.
The Department of Health and Hospitals, in a news release, said samples were negative for Naegleria fowleri, meaning increased chlorine levels in the water system have controlled it.
The water system was one of two that tested positive for the amoeba last year.
"While the water in St. Bernard Parish was always safe to drink, these negative test results give us confidence that it is now safe for all uses," said DHH Secretary Kathy Kliebert. "We will continue to work with parish leaders to monitor the system so that all families in the parish can feel safe."
The federal Centers for Disease Control and Prevention confirmed this week that two water samples from 11 locations along St. Bernard's system were all negative.
Last fall, DHH announced that testing confirmed the presence of the amoeba in the water system in St. Bernard and in Water Works System No. 1 in DeSoto Parish.
In response to the deaths and the positive test results, DHH in November issued an emergency rule requiring that water systems in the state maintain a higher residual disinfectant level and increase their number of sampling sites by 25 percent.
Most drinking water systems in Louisiana were required to meet the new higher standard by Feb. 1. DHH also convened a scientific working group to gather as much information and research as it could about how to protect Louisiana families from the amoeba.
Free chlorine or chloramine residual at 0.5 milligram per liter or higher will control the amoeba, provided the disinfectant is present at that level throughout the water supply system continually, the department said.
"We are encouraged because these test results confirm that maintaining a certain free chlorine or chloramine residual in water systems can control this amoeba and protect families," said J.T. Lane, assistant secretary for public health. "This is why DHH issued an emergency rule last year that we believe will make the water that we drink, bathe and play in safer."
The department said out of an abundance of caution, it will conduct additional sampling and testing in St. Bernard Parish later in the year as temperatures grow warmer, making water more inviting for the amoeba to live in.