[StBernard] Lax chlorine standards likely contributed to brain-eating amoeba in St. Bernard water

[Westley Annis]

Lax chlorine standards likely contributed to brain-eating amoeba in St.
Bernard water

Print Benjamin Alexander-Bloch, NOLA.com | The Times-Picayune By Benjamin
Alexander-Bloch, NOLA.com | The Times-Picayune 
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on September 19, 2013 at 7:00 PM, updated September 20, 2013 at 8:13 AM

The administrator who oversees safe drinking water for Louisiana said St.
Bernard Parish's water supply has not been under any recent state
enforcement orders prompted by low chlorine levels, because the parish's
water has tested positive for traceable amounts of disinfectants over the
last several years.

Those tests, however, did not seek a deadly brain-eating amoeba found at
four sites in St. Bernard this month, which killed a 28-year-old man in
Arabi in 2011 and a 4-year-old boy in Violet last month. And officials said
they found no chlorine at all at four sites earlier this month that tested
positive for the amoeba, Naegleria fowleri.

If sites in the parish water supply test positive for any chlorine levels at
all - anything above zero chlorine in the water - then the would not come
under state or federal enforcement, according to Jake Causey, the state
Department of Health and Hospitals administrator who oversees the state's
safe drinking water.

Monthly testing in St. Bernard's water had always detected at least some
minimal chlorine levels in recent years, according to DHH and parish
documents. But chlorine at certain sites at times dip below 0.5 mg/L, with
many sites in Arabi, Violet and Yscloskey regularly hovering right around
that dangerous threshold.

The deathly amoeba can survive and thrive in water that has chlorine levels
at 0.4 milligrams per liter or below.

Recent tests by DHH found no chlorine at all at the sites where the amoeba
was found.

"From the routine monitoring, we came to the conclusion that we didn't have
any issues with chlorine residuals," Causey said. "But then when this death
occurred and it was confirmed that it was this amoeba, my district engineer
went out and checked the chlorine residuals near where this had occurred.
and it was a very different story then what we were seeing in the routine
monitoring.

"And then when we looked back out at the Arabi area as well we saw something
similar."

Causey confirmed on Thursday that several other areas, in addition to the
Violet and Arabi sites, have tested negative for any traces of chlorine in
the most recent DHH testing. Those additional sites include areas in
Yscloskey and Delacroix, he said.

New amoeba testing methods

While testing methods for chlorine have not changed between 2011 and 2013,
testing methods for the Naegleria fowleri amoeba recently have improved.

The amoeba was blamed for the 2011 death of the 28-year-old St. Bernard man,
who died from a brain infection after he was exposed to the amoeba in his
home's water system. Then last month, a 4-year-old Mississippi boy died from
the same infection after having allegedly been exposed to the amoeba while
playing on a Slip 'n Slide in Violet.

In both instances the amoeba was transported into the victims' brains by
water that traveled up their noses. Both the federal Centers for Disease
Control and Prevention and state DHH have said people cannot contract the
infection by drinking contaminated water.

The 2011 incident was the first ever recorded in Louisiana involving this
microorganism. DHH and CDC testing in that case found the amoeba inside hot
water system in the man's home. Further testing did not find the amoeba in
the parish water system.

Because of that, officials assumed that the amoeba was not present elsewhere
and was confined to that Arabi home's piping.

A much more intricate testing method used after the second death in recent
weeks showed the amoeba was actually in the parish's water system.

The new water sampling method, developed at CDC, uses what's essentially a
dialysis filter that can trap microbes, including parasites, bacteria, and
viruses. This method filters much more water than the testing used back in
2011.

"It is a lot better," Louisiana State Epidemiologist Dr. Raoult Ratard said
on Thursday. "In 2011, they had tested something like 1 liter of water (at
each site) and now they are testing 100 or so liters. So, you multiply your
chances of finding (the amoeba) by more than 100 times."

Earlier this month, the CDC confirmed the amoeba at four different sites,
three in Arabi and one in Violet.

Two of the three sites in Arabi where about a block away from the home where
the first victim died in 2011. The fourth site -- a fire hydrant in Violet -
was just a block or so from the home where the 4-year-old boy contracted the
infection, Causey said.

"I think that there certainly is a possibility that (the amoeba) has been in
St. Bernard the whole time and that the testing in 2011 was just not as
extensive," said Jonathan Yoder, member of a team of CDC scientists who
collects data on the amoeba when there are cases of disease.

The current chlorine levels

The parish has been "burning and flushing" its water system for weeks,
upping the amount of water and the amount of pure chlorine to try to reach
chlorine residual levels of 0.5 mg/L or higher. So far, the system still has
not reached that benchmark.

DHH on Thursday and Friday is expected to test another 100 sites in the
parish to gauge chlorine levels.

On Thursday afternoon, monitors found only a 0.1 mg/L chlorine residual at a
site outside Chalmette Elementary School. At a site outside Andrew Jackson
Middle School, about a mile away also in Chalmette, the parish water tested
at 0.6 mg/L.

DHH officials expect that the system's flushing will have to continue for
several more weeks.

Once the parish water supply reaches 0.5 mg/L, then DHH officials will send
new samples to CDC for its scientists to determine whether the amoeba still
is active.

Yoder said on Thursday that Naegleria fowleri can form a cyst - a hard outer
shell - to survive in chlorinated water. But eventually - if 0.5 mg/L of
chlorine is maintained - then the amoeba will die off because it will no
longer be able to multiply and its food source will be killed off.

To make sure it is no longer in the water, CDC scientists will test for the
amoeba's DNA. Then they will try to culture the organism, putting it in a
plate of bacteria to see if the amoeba eats, grows and multiply. Even in
cysts, Naegleria fowleri would come out of their shell and start feeding and
multiplying if they were placed in such an environment, Yoder said.

But the idea is that if the water stays at 0.5 mg/L or above of chlorine for
long enough, then there would no longer be detectable.

"Disinfection of 0.5 through the whole system is the way to prevent,"
Naegleria fowleri amoeba, Yoder said. "But we are not a regulatory agency
and that is just the science, and so in the long term, how to maintain that
0.5 level, that needs to be a decision made the by the state of Louisiana
and we are happy to work with them and the EPA in making those decisions."

Causey did say that DHH also will work with St. Bernard "to redefine their
chlorine monitoring program."

St. Bernard Parish government has set up a hotline - 504.278.4251 - for a
complete list of all CDC and DHH recommendations to safeguard against
catching the infection. For more information on preventative measures, visit
the CDC website: 

http://www.cdc.gov/parasites/naegleria/prevention.html

 Safety tips also can be found at http://dhh.louisiana.gov/WaterFacts