What is a parasite?
Before you self-diagnose, it’s important to understand what a parasite is. “A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host,” according to the US Centers for Disease Control and Prevention (CDC). There are three classes of parasites:
- Protozoa, which are tiny, one-celled organisms that typically live in the intestines, blood, or tissue;
- Helminths, which are parasitic worms such as tapeworms, roundworms, and thorny-headed worms; and
- Ectoparasites, which are ticks, fleas, lice and mites that attach to or burrow into the skin.
Parasites can cause disease and even death, but fortunately, if caught early, the infections can usually be treated with medication.
You ingested (or swam in) some questionable water
Whether you were travelling abroad and drank from the tap or went to the lake around the block and splashed around for a bit, ingesting contaminated water is one of the most common causes of parasites, according to Dr Daliah Wachs.
You enjoy a rare steak
Tend to prefer your foods on the rare side? It might not be the best option if you’re looking to avoid a parasite. “Ingesting raw or undercooked beef or pork can lead to [infection by] the Taenia type of intestinal tapeworms,” says Dr Dana Hawkinson. “Eating certain raw fish can lead to [infection by] diphyllobothrium, [a type] of intestinal tapeworm. Additionally, ingestion of contaminated food or water can lead to an Ascaris infection.” Ascaris intestinal roundworms can grow up to 35 centimetres in length and lead to intestinal blockage, so you definitely want to avoid them.