While many people are familiar with parasites such as intestinal flukes or tapeworms, others exist that are the stuff of Alien-style horror movies. Actually, no known Earthly parasite deposits eggs in a human stomach that later hatch and burst out of the chest cavity … at least not yet. But the following parasites are all real; they seek out human hosts, sometimes with hideous results.
5. Filarial Worm
Spread by mosquitoes and black flies, these worms enter the human body as larvae and the infection causes lymphatic filariasis, the most spectacular and scariest form being elephantiasis. Elephantiasis leads to a swelling of extremities due to the pooling of blood and fluids in the limbs; sometimes, this condition strikes the genitalia. Once present in the body, these little worms can live an average of six to eight years, producing millions of larvae that circulate through the bloodstream. An estimated 120 million people worldwide are infected with this parasite, mostly in Africa.
4. Leishmania Protozoa
Spread by sandfly bites, these little organisms leave behind gruesome evidence of their presence. Once these bites become infected, they fester into open sores that may not heal for more than a year. While cutaneous (skin) leishmaniasis is ugly, visceral leishmaniasis is more insidious, inflaming the spleen and liver and often resulting in death. In northern Africa and southern Europe, leishmaniasis typically infects dogs and rats, although the human variety is pervasive in certain regions of the Middle East and South America. According to the World Health Organization, around 1 million new cases are diagnosed each year, resulting in 20,000 to 30,000 deaths.
3. Naegleria Fowleri (Brain Eating Amoeba)
This amoeba made national news in the summer of 2016, when it killed a teen who had visited the U.S. National Whitewater Center in Charlotte. Naegleria fowleri lives in warm freshwater lakes, but can also be found in tapwater or poorly treated swimming pools. It’s not deadly if you drink it, but if it gets up your nose, it can possibly penetrate the thin lining at the back of the nasal cavity and jump the blood-brain barrier — which keeps out most parasites — to enter the brain. There, it starts feeding on brain tissue. The condition it causes, primary amoebic meningoencephalitis, presents symptoms similar to bacterial meningitis. Sufferers die a painful death, with symptoms including severe headaches, nausea, fever, seizures and hallucinations.
According to the CDC, 138 people have been infected since 1962; only three survived the ordeal. In addition to being careful when swimming in a warm lake — using nose plugs could prevent infection — avoid irrigating your nasal passages using a neti pot filled with tapwater. Two people in Louisiana died from this parasite doing just that in 2011.
2. Loa Loa Eye Worm
Although related to the filarial worm mentioned in No. 5 above, we broke the Loa loa eye worm out by itself because it is ghastly stuff. This roundworm parasite lives under the skin — much like ringworm — but it often enters the eye (hence the “eye worm” name). It can then be visible externally in the eyeball, but the host can sometimes even see this worm swimming inside his or her own eyeball as it crosses their field of view, much like “floaters.” Spread by fly bites, this worm is endemic in western Africa, especially in the Congo and Sudan. Treatment for the Loa loa eye worm includes chemotherapy drugs to target the parasite eggs in the bloodstream and possible surgical removal.
1. Guinea Worm
The first sign of Guinea worm (Dracunculus medinensis) disease is a burning ulcer, usually on the lower part of the leg. It gets much worse — a worm then begins to emerge from the ulcer. Your first impulse might be to tug on the end of the worm, which is a very bad idea, as it can then break off and burst inside your body, releasing millions of larvae. Instead, the emerging worm must be slowly wound around a stick, which can take several weeks. Although Guinea worms are about the width of a spaghetti noodle, they may be almost 3 feet long. This disease is spread through water contaminated with the Guinea worm larvae. That burning sensation a victim feels is the worm’s own evolved strategy to get the host to relieve the sensation by dipping the lesion in water, reinfecting the water supply and starting the cycle anew.
Thankfully, Guinea worm infections are down from 3.5 million cases in 1986 to 22 cases in 2015, mostly due to educational programs to combat the disease. The worm is now found in only four African nations (Chad, Ethiopia, South Sudan and Mali) and could well be eradicated in the next decade.
One More: Lone Star Tick
Who knew the term “meat sweats” described a real thing? A strange but true infection now plagues the “Deep Fried Belt” of the southern United States. A tick-borne condition can turn infected meat-eaters into vegetarians … or least make them allergic to red meat. The bite of the lone star tick (Amblyomma americanum), named for the tiny white dot visible on its back, is responsible for spreading the allergy. The problem stems from a carbohydrate known as “alpha-gal” carried by the tick. This carbohydrate is also found in red meat, and the immune response mounted by the body to the tick bite can cause an allergic reaction when the host later eats meat.
Lest you think the tick can only strike in Texas, it is found throughout the Eastern U.S. Sufferers might have to avoid more than the Sunday barbecue. As dedicated vegans (those who eschew all animal products) know, animal-based gelatins turn up in some strange places, from pill casings to Jello to marshmallows. While doctors only diagnosed the alpha-gal allergy a few years ago, and many are not even aware of the condition, the Washington Post estimates thousands of cases have been diagnosed. Nothing is more terrifying than a meat allergy deep in southern fried-meat country.