Plagues,
Pestilences and Diseases
Brain-eating amoebas blamed in three deaths
By Madison Park, CNN
STORY HIGHLIGHTS
* 3 people have died after a waterborne amoeba infected their
brains, the CDC confirms.
* While rare, the amoeba, called Naegleria fowleri, is more
than 95% lethal
* Amoebas can enter the human nose after a person jumps or
dives into warm fresh water
(CNN) -- It's eerie but it's true: Three people have died this
summer after suffering rare infections from a waterborne amoeba
that destroys the brain.
This is the time of year when there is an uptick in cases. The
amoebas flourish in the heat -- especially during the summer
months in the South, thriving in warm waters where people swim.
Health officials usually record about two to three cases in a
given year -- 1980 was the highest with eight deaths. And most of
the time, they occur in children and teenagers.
"These are rare infections, but super tragic for families," said
Jonathan Yoder, the waterborne disease and outbreak surveillance
coordinator at the Centers for Disease Control and Prevention. "We
don't want to minimize how hard it is for families."
'Amoebas act extremely quickly'
The amoeba, called Naegleria fowleri, is the only type that
infects humans and is more than 95% lethal. The first death in
2011 occurred in June in Louisiana, according to the CDC.
A 16-year-old died Saturday after becoming infected by an amoeba
in Brevard County, Florida, according to CNN's affiliate WFTV. The
amoeba could have entered the teen's body as the teen swam in a
nearby river.
Her mother, P.J. Nash-Ryder, said her daughter complained of a
headache, threw up 20 times and ran a fever as high as 104
degrees.
"She would sit up in bed and just look at me, and I would ask her
what was wrong," Nash-Ryder said. "She would say, 'I don't know.'
And I'd tell her to lay back down. Her eyes were rolling ... and
she wouldn't shut them all the way."
A spinal tap showed that Naegleria fowleri was present in her
spinal fluids.
In another case, the Virginia Department of Health confirmed
Friday that a child from central Virginia died from primary
amoebic meningoencephalitis, which is caused by the amoeba. The
Richmond Times Dispatch said the child was a 9-year-old boy from
Henrico County.
The child died within the last few weeks, said Dr. Keri Hall, the
state's director of epidemiology. She declined to share other
details. Virginia's last confirmed case was in 1969.
Amoeba infections in humans are extremely rare. The CDC found 32
reported cases in 10 years -- compared with 36,000 drowning deaths
from 1996 to 2005.
Rare but deadly amoeba infection hard to prevent
The median age of the victims is 12, possibly because children and
teenagers are more likely to play and swim in water. Nearly
two-thirds of those killed by the amoeba are children under the
age of 13.
The amoebas enter the human body through the nose after an
individual swims or dives into warm fresh water, like ponds,
lakes, rivers and even hot springs.
Lurking in fresh waters during the summertime, they're more likely
to infect humans in July, August and September.
It's unclear why out of the millions of people who swim in the
same fresh waters, a small fraction of people are infected by the
amoeba.
"It's difficult to know," Yoder said. "It's not a disease that's
easy to study because the end result is so severe. It's difficult
to study in the lab."
Scientists speculate that the lack of certain antibodies could be
why some children get infected, while others who've swum in the
same water don't, said Francine Cabral, professor of microbiology
at Virginia Commonwealth University School of Medicine.
The amoeba is not a parasite. A human is an "accidental end point
for the amoeba after it's forced up the nose," Yoder said. It does
not seek human hosts.
But when an amoeba gets lodged into a person's nose, it starts
looking for food. It ends up in the brain and starts eating
neurons.
"It causes a great deal of trauma and a great deal of damage,"
Yoder said. "It's a tragic infection. It's right at the frontal
lobe. It affects behavior and the core of who they are -- their
emotions, their ability to reason -- it's very difficult."
Early symptoms include headache, fever, nausea, vomiting and neck
stiffness. Later symptoms include confusion, lack of attention to
people and surroundings, loss of balance, seizures and
hallucinations.
The amoeba multiplies, and the body mounts a defense against the
infection. This, combined with the rapidly increasing amoebas,
cause the brain to swell, creating immense pressure. At some
point, the brain stops working.
Death typically occurs three to seven days after the symptoms
start.
At hospitals, the infection is often mistaken for bacterial
meningitis. Even when the diagnosis is made, the infection is
difficult to treat.
The primary treatment for Naegleria infection is amphotericin B,
an antifungal medication injected into the veins and brain.
But so far, only one person -- back in 1978 -- is known to have
survived an infection, Yoder said.
Everybody panics because the amoeba infection is so deadly, but
Cabral reminded: "The incidence of this disease is very very
small, but when it happens it's tragic."
Here are the CDC's tips for prevention:
* Refrain from activities in warm, untreated or poorly treated
water, especially when water levels are low and temperatures are
high.
* Hold the nose shut or use nose clips when swimming in warm fresh
water.
* Avoid digging or stirring up underwater sediments while
submerged in shallow, warm freshwater areas.