Parasites

Types of parasite

There are 4 different groups of parasite: roundworms, single-celled protozoa, tapeworms and flukes.

Roundworms: these may affect up to 25% of the world’s population. They range from the blood sucking hookworm that can grow to the size of a pencil to the highly contagious pinworms which are commonly picked up in crowded areas such as schools.

Protozoa: minuscule, single-celled organisms, protozoa form cysts, or a resting stage, where they become resistant to temperature extremes, chemicals and drying. Humans can easily ingest these small cysts and many of us have been exposed. Usually they’re kept in check by our immune systems, but if we become run down due to stress or illness an outbreak can occur.

Tapeworms: common throughout the world, tapeworms are long and ribbon-like. Humans can ingest tapeworm larvae by eating raw or undercooked beef, pork and fish or by coming into contact with infected animals or contaminated grains. Tapeworms live in our intestines and absorb nutrients through their skin.

Flukes: these are tiny flat worms that look like odd-shaped pancakes. Humans can become infected by eating raw or undercooked seafood, infected vegetation such as water chestnuts or watercress or by drinking or wading in infected water. Once inside the body, flukes migrate to various organs and may cause liver swelling, jaundice, weakened lungs and blood clots.