1. Primary amebic meningoencephalitis
Primary amebic meningoencephalitis (or PAM as it is known by those acronym-loving physicians) is caused by an amoeba called Naegleria fowleri. But aren’t amoebas those cute little single-celled organisms that we’ve all spied on through middle school microscopes and laughed at in Far Side comics? Nothing scary there.There’s only one thing the brain-eating amoeba enjoys besides neuronal soup: warm weather. This mind melting nemesis is largely found in still waters in the southern US, but global warming is allowing it to creep up to areas further north. Just one good snort of contaminated water sends this hungry little amoeba to the brain buffet.
This amoeboid parasite is a glutton, and that is its undoing. A smart parasite, like Toxoplasma gondii, goes to sleep in the brain so it won’t kill its host. But Naegleria fowleri goes on a brain devouring binge with no thought to sustainability and literally eats its host to death.
Naegleria fowleri is rather prevalent, but human infection is very rare. The bad news for those who are susceptible is that there is no cure. You will be host to this unwelcome guest for about six days before there isn’t enough brain to support the two of you any longer. So if you can’t resist the urge to go skinny dipping, at least wear some nose plugs.
In 1993, the single-celled parasite Cryptosporidium brought gastrointestinal misery to over 400,000 people in Milwaukee, overwhelming city hospitals and even killing at least 100 of these unlucky souls. The parasite is a common pathogen in cattle and somehow found its way into the city water supply (in other words, people were drinking water that had cow patties in it).
The Cryptosporidium cysts expelled by infected cattle (or infected people) are very tough, even resistant to chlorine. People can become infected from contaminated water in lakes, pools, or water fountains, or by taking care of infected babies or patients. Once ingested, the cysts break open and the parasites inside invade your intestinal epithelial cells. They steal nutrients from your cells in order to replicate and make more cysts that get back out into the environment after turning your insides into their ultimate water slide.
Cryptosporidium is the microbial equivalent of Turbo-Lax. With no vaccine or effective treatment available, patients just have to stay hydrated, hunker down with plenty of aloe-infused TP, and wait out the unpleasant infection, which can last up to two very long weeks.
3. Cerebral sparganosis
Our next water dwelling devil is called candiru and it is the star of every man’s nightmare. Candiru is also known as the vampire fish, which is an awesome nickname, but what this toothpick-shaped catfish is purported to do is not cool, bro. Not cool at all. Any guesses?
Contributed by: Bill Sullivan
Swim with Bill on Twitter.
The original version of this article appeared on BuzzFeed Community.
Bauer IL (2013). Candiru--a little fish with bad habits: need travel health professionals worry? A review. Journal of travel medicine, 20 (2), 119-24 PMID: 23464720