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5 Rare Parasites Found in the Human Body

Japanese Lung Fluke

Paragonimiasis is an infection caused by a fluke, a type of parasitic worm, most often paragonimus westermani and paragonimus kellicotti in humans. It usually affects the lungs, although it can infect other parts of the body, such as the brain. The good news? Only crayfish and crabs carry the parasites responsible for this infection.

The risk of being infected with a lung fluke is highest in Japan, Korea, China, the Philippines and Indonesia, as well as some regions of Africa and South America, but the P. kellicotti parasite is also found in crayfish in the American South and Midwest.

After you consume a lung fluke, the first symptoms to appear are usually abdominal pain, diarrhea, fever, coughing and chest pain while the parasite travels from your stomach through your body and into your lungs. Symptoms may often look a lot like bronchitis, meningitis or even tuberculosis.

Lung flukes grow to be anywhere from about 0.3 to 0.5 inches (7.5 to 12 millimeters) in length, and just like the parasites we've already talked about, lung flukes can live inside a human host for as long as 20 years [source: CDC].