Brain-eating amoeba fight could take weeks

Officials in St. Bernard Parish say it could take weeks to flush enough chlorine through the water supply to minimize the threat of parasites, particularly a rare brain-eating amoeba that public health experts blame for the August death of a 4-year-old boy who likely contracted the almost-always lethal disease on a Slip ’N’ Slide at a trailer home near Violet.

Subsequent tests by the Louisiana Department of Health & Hospitals showed that water on the inflatable toy was tainted by the Naegleria fowleri amoeba, which also turned up in a hose attached to an outdoors faucet and in a toilet tank inside the home, the agency confirmed on Sept. 5.

For just under an hour Thursday evening, members of St. Bernard’s Water and Sewer Committee met to pose questions to Parish President David Peralta, hoping “to try to ease some of that anxiety that is out there,” Councilman Ray Lauga said.

Since getting confirmation of the amoeba’s presence in parts of the parish water system, Peralta said, officials have flushed the water with 500 pounds of chlorine per day. “For obvious reasons, we’re trying to increase the flow of water, which will actually increase the flow of free chlorine,” he said.

The questioning, which grew contentious at times, focused mainly on what Peralta knew about the amoeba and when. Peralta denied that the parish’s water supply had become worse in the past year, but he couldn’t say whether it faces a greater risk of contamination than water in neighboring municipalities.

The free-living microscopic amoeba is common in warm, stagnant water, say health experts, who are unsure why so few people ultimately become infected, given how many likely come into contact with the amoeba.

State tests showed water in several areas in the parish — including near where the boy became infected — with low chlorine levels, which have plagued St. Bernard for years, according to data collected by the parish, which tests the water at 32 locations each month. “Obviously, we’re doing increased testing now,” Peralta said.

Though public health specialists highlight the difficulty of determining the cause of contamination by the amoeba, several experts say low levels of chlorine could be a factor, because water treated with chlorine is unlikely to test positive for the single-celled organisms.

Now, St. Bernard officials are working to get the chlorine level up to .5 parts per million. State and federal drinking water regulations do not specifically address monitoring or treatment for amoebas, state health experts say, but they note that increased chlorine is likely to control the amoeba.

Peralta said the process of raising the chlorine level, currently underway, could take another three weeks. “Levels are going up significantly already,” he said.

During Thursday’s questioning, Councilman Manuel “Monty” Montelongo seemed skeptical that the visiting 4-year-old had contracted the deadly disease in the parish. “So the circumstances surrounding this horrible death, I don’t think anybody can tell us for sure that the amoeba came directly from our system?” he asked.

In an interview Thursday, Jake Causey, chief engineer for DHH, said the state agency tested the water at 10 sites in St. Bernard, particularly in areas near where the boy is believed to have become infected.

Several areas tested low for chlorine levels, he said. “Some were trace, and some were non-detect,” he said. “We had 10 filtered samples, and four of those filtered samples came back positive for the amoeba.”

Of the positive tests, Causey said, two samples came from homes, and two were from taps installed on fire hydrants. For his part, Causey speculated that the parish’s sharp population drop in the years since Hurricane Katrina could be a factor, since fewer residents are using the water, which means it’s not moving as actively through the system.

“It’s just that the system has much less demand now, with fewer customers than before,” he said, “so the water may be sitting in the pipes longer, allowing that chlorine to dissipate before it’s used.”

In 2012, St. Bernard’s population was about 41,600 people, according to U.S. Census estimates, down by more than 25,000 from 2000.

Causey said the parish installed about 50 automatic flushing stations in recent years to cope with the problem of reduced usage. The equipment dumps water out of the system on a timer to allow newer, fresher water to come in from the treatment plant.

“It’s just very low demand in that area, and the water is just sitting there, so that’s just kind of one theory, but we don’t know why,” he said.

Several public health experts agreed that the parish’s reduced water usage could be a leading explanation for the low chlorine levels and the presence of the amoeba.

“When the water pressure goes down, then things from the outside can come in, and so that’s one way the amoeba can come in,” said LuAnn White, the interim dean of the School of Public Health and Tropical Medicine at Tulane University. “If there’s any broken pipes — and goodness knows all over southeast Louisiana, we have broken pipes, but particularly in areas where you may have houses that have been torn down — you’re more likely to have broken pipes that are not fixed, they’re leaking.”

William Schaffner, chairman of the Department of Preventative Medicine at Vanderbilt University Medical Center, agreed. “If their integrity is disturbed or if they’re not run absolutely rigorously, you can have bacterial and occasionally viral contamination,” he said in an interview.

But White said the 4-year-old boy’s death could serve as a wake-up call.

“The fact that they found it in the water system is reason to take notice,” she said. “It seems like they’re doing the appropriate things, but they’ve just got to keep testing it and make sure they get the water system cleaned up.”

Since Naegleria fowleri cannot be contracted by drinking water, public health officials say the local water supply remains safe to drink.

The August death marked the third Naegleria fowleri-related death in Louisiana since 2011, officials said. Most people who contract the disease — 32 total from 2001 to 2010 nationwide — did so after swimming in warm, freshwater bodies of water and ingesting contaminated water through their noses. When infections occur, the water containing the amoeba enters the body through the nose and is pushed into the brain.

Only 128 people have reportedly contracted the disease in the United States since 1962, according to the Centers for Disease Control and Prevention. Only one of those patients survived, although news reports indicate that a 12-year-old Arkansas girl who became infected this summer and was hospitalized has been successfully fighting the infection.

The two Louisiana residents who died of the fatal brain infection in 2011, including a St. Bernard man, became sick after using contaminated tap water in neti pots to irrigate their sinuses.

State health officials responded by warning residents to use distilled or boiled tap water in the teapot-like containers, to avoid the risk of contracting the disease.

“I’m not a scientist, so I don’t know the answer to that. It is rare, it’s a rare occurrence, but they’re two totally different situations,” Peralta, the parish president, said when asked during Thursday’s meeting about the fact that two people became infected in three years in the same small parish.

Not everyone in the crowd of nearly 100 people left satisfied.

“I mean we didn’t get nothing out of it,” said Chalmette resident Althea Riley. “What did we learn? Nothing. We’re still at ground zero.”

Since word spread about the amoeba this month, Riley said, she’s taken precautions and now uses bottled water almost exclusively.

“I wash my face with the bottled water, brush my teeth with it,” she said. “I like to take baths, but now I’m taking showers.”