A brain-eating parasite that kills 97% of those infected, including a Hudson Valley teen, is resurfacing.

According to the Centers for Disease Control and Prevention, Naegleria fowleri, or “brain-eating amoeba,” causes an almost always fatal infection in the brain. It is commonly found in warm freshwaters like likes rivers and hot springs. The amoeba typically enters through the nose and travels to the brain, causing the fatal infection.

The amoeba was confirmed this week in drinking water in Louisiana, reports the New York Post. You can't be infected by drinking water, only if contaminated drinking water enters your nose.

According to the CDC, Naegleria fowleri is found around the world and in the United States in the following areas:

  • Bodies of warm freshwater, such as lakes and rivers
  • Geothermal (naturally hot) water, such as hot springs
  • Warm water discharge from industrial plants
  • Geothermal (naturally hot) drinking water sources
  • Swimming pools that are poorly maintained, minimally-chlorinated, and/or un-chlorinated
  • Water heaters. Naegleria fowleri grows best at higher temperatures up to 115°F (46°C) and can survive for short periods at higher temperatures.
  • Soil

Naegleria fowleri is not found in salt water, like the ocean, officials say.

The fatality rate is over 97%. Only 4 people out of 143 known infected individuals in the United States from 1962 to 2016 have survived, according to the CDC.

In 2016, 19-year-old Kerry Stoutenburgh of Kingston died after she contracted the deadly brain-eating parasite. 

Naegleria fowleri infections are rare. From 2007 to 2016, 40 infections were reported in the U.S. 36 people were infected by recreational water, three people were infected after performing nasal irrigation using contaminated tap water. One person was infected by contaminated tap water used on a backyard slip-n-slide.

Naegleria fowleri infections are most common during the summer months of July, August and September. Infections are more likely to occur in southern states, but can also occur in northern states.

Initial symptoms of a headache, fever, nausea, or vomiting start about five days after infection. Symptoms increase to include stiff neck, confusion, lack of attention to people and surroundings, loss of balance, seizures and hallucinations.

The disease progresses rapidly and usually causes death within about five to 12 days, the CDC reports.

There are several drugs to fight Naegleria fowleri, but because almost all infections have been fatal, the effectiveness is unclear.

CBS reports, you should always assume that there is a low level of risk anytime you swim, dive, or water-ski in warm freshwater. It's recommended you hold your nose or use nose clips while swimming.  You should also avoid digging or touching sediment.

The infection can't be spread from one person to another.