A 10-year-old Texas girl contracted a brain-eating amoeba after swimming in the Brazos river — the infection has a 4% survival rate
- A 10-year-old Texas girl contracted Naegleria fowleri, or a "brain-eating amoeba," while swimming in the Brazos River last week.
- The amoeba causes a rare, but almost always deadly brain infection called primary amebic meningoencephalitis (PAM). PAM has a fatality rate of more than 97%.
- This is the 147th case of Naegleria fowleri in the US since 1962; only four people have survived the infection.
- These amoebas can be found in freshwater lakes, rivers, and hot springs, and enter the brain through the nose.
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Ten-year-old Lily Mae Avant is lying in the Pediatric Center of the Cook Children's Hospital in Fort Worth, Texas as a devastating infection attacks her brain tissue.
On Monday, the girl complained of a headache and was sent home from school with a fever. Her parents rushed her to the hospital Tuesday morning after Avant was unresponsive, according to a Facebook post from her cousin Wendy Scott. At first, doctors thought the girl had bacterial meningitis. By Thursday, they'd concluded that, instead, Avant had a deadly brain infection called primary amebic meningoencephalitis (PAM).
PAM is caused by Naegleria fowleri, or the "brain-eating amoeba," that can be found in warm, freshwater around the world. Just days before she checked into the hospital, CBS Dallas-Fort Worth reported, the 10-year-old had been swimming in the Brazos River.
This infection causes intense brain swelling and is almost always fatal, according to the US Centers for Disease Control and Prevention (CDC). PAM has a fatality rate of more than 97%; of the 147 cases in the US since 1962, only four people have survived.
Earlier this year, a 59-year-old North Carolina man died of the infection after swimming at a water park. In October 2018, a California boy contracted the amoeba after entering a hot spring in the Eastern Sierras, according to a CDC report. His symptoms didn't set in until 12 days after he'd gone swimming, then he was dead within three days.
Naegleria fowleri enters our brain through the nose
According to the CDC, Naegleria fowleri is never found in saltwater; rather, it's most common in freshwater lakes, rivers, and hot springs. Infections occur when people go swimming or diving in these bodies of water.
When the sediment in a lake or river gets disrupted, these brain-eating amoebas are stirred into the water, and then that contaminated water gets inhaled into a swimmer's nose. The amoeba then uses the olfactory nerve to migrate to the brain, where it causes PAM.
People can't get infected from swallowing contaminated water, however, infections have occured after swimmers inhaled inadequately chlorinated swimming pool water or heated and contaminated tap water, the CDC reports.
Naegleria fowleri thrive in warm waters, and grow best in temperatures up to 115 degrees Fahrenheit.
Our brains are moist and warm, just like amoebas' ideal habitat, toxicologist Bill Sullivan wrote in The Conversation. "But the brain doesn't have bacteria for the amoeba to eat, so the organism attacks brain cells for nutrients."
As the parasite eats its way through the brain, our body's immune system tries to fight back, which causes the intense swelling and inflammation in our skulls, Sullivan said.
The pressure from this swelling eventually interrupts the brain's connection to the spinal cord, and can respiratory failure, among other consequences.
The infection causes vomiting, seizures, brain swelling, and death
Initial symptoms of PAM can start between up to 9 days after infection, and include headache, fever, nausea, or vomiting. Later symptoms can include stiff neck, confusion, loss of balance, seizures, hallucinations, and coma. After symptoms manifest, the infection progresses rapidly and usually causes death within about 5 days, the CDC reports.
But these brain-eating amoeba are difficult to detect and even harder to treat, Sullivan wrote.
"The initial symptoms can easily be mistaken for a less serious illness, costing valuable treatment time," he said. Sullivan added that there is no quick diagnostic test for the amoeba; patients are often mistreated for viral or bacterial meningitis, just like Avant.
By then, it is often too late for patients, as "the presence of the parasite leads to rapid and irrevocable destruction of critical brain tissue."
This is the 36th brain-eating amoeba case reported in the US since 2009
Very few people survive an encounter with brain-eating amoeba. Avant is the 147th case of PAM in the US in the last 57 years. Of those 147 people, only four have survived — one in 1978, two in 2013, and, most recently, one in 2016. Avant's family hopes she will be the fifth survivor.
Between 2009 and 2018, 36 PAM infections were reported in the US. Of those cases, 32 people were infected by recreational water, three people were infected after performing nasal irrigation using contaminated tap water, and one person was infected by contaminated tap water used on a backyard slip-n-slide, according to the CDC.
Typically, most Naegleria fowleri cases occur in the 15 southern-tier states, with more than half of all infections occurring in Texas and Florida.
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