The brain-eating amoeba that killed a 9-year-old Kansas girl last week is an organism that thrives in warm fresh water and can be found in lakes, rivers, hot springs and soil, according to the Centers for Disease Control and Prevention.
The victim, Hally "Bug" Nicole Yust, reportedly had swum in several lakes over the past few weeks near her home in Spring Hill. The Kansas Department of Health confirmed that she died from primary amoebic meningoencephalitis (PAM) caused by the amoeba, Naegleria fowleri, which she likely inadvertently inhaled via lake water.
"Once forced up the nose, it can travel to the brain, where it digests brain cells," Jonathan Yoder, an epidemiologist at the Centers for Disease Control and Prevention, told Discovery News. "It's a very tragic disease that thankfully is very rare."
Aside from its rarity, the amoeba "is not looking to prey upon human victims," he said. "They usually go after bacteria in water and soil."
As single-celled organisms, amoebas do not even have brains.
However, Naegleria species, including this disease-causing one, can transform themselves into three different basic "body" types.
"This one-celled organism hunts and eats bacteria as an amoeba, swims around looking for a better environment as a flagellate, and then hunkers down and waits for good times as a cyst," said Simon Prochnik, a computational scientist at the U.S. Department of Energy's Joint Genome Institute. "It is a very rare process to go from amoeba to flagellate like this."
Prochnik, who sequenced the genome of a Naegleria species, explained that when environmental conditions are not favorable, the "stressed" amoeba can quickly grow two tails, transforming it into the flagellate. It can then swim and move around to a better spot, similar to the way that human sperm travel.
To support these three body or "personality" types, as Prochnik calls them, the organism is packed with genes: 15,727 of them. To put that into perspective, humans have 23,000 protein-coding genes.
Since the creature is so versatile, it can lurk in warm, moist places for extended periods.
Two Louisiana residents contracted the amoeba a few years ago after using a neti pot, which looks like a teapot and is used for nasal irrigation to relieve sinus problems. The CDC determined that the organism was living in the victims' home water system systems. The individuals apparently did not boil the water before placing it in the neti pots.
Yoder said it is important to follow the directions included with neti pots. The instructions usually mention that users should put distilled, boiled water in them and not just water right out of the tap.
If users don't follow these instructions, there is a slim chance they too might get the disease caused by Naegleria fowleri.
According to CDC data, the fatality rate is over 97 percent. Only three people out of 132 known infected individuals in the United States from 1962 to 2013 have survived.