What is a Parasite?

Welcome to a website about parasites and the ANU researchers that study them.  If you’re interested to know “what exactly is a parasite?” and “why would anyone want to study them?” do read on!

A parasite can be defined as “An organism that lives in or on an organism of another species (its host) and benefits by deriving nutrients at the other's expense (https://www.lexico.com/definition/parasite). 

There are three major classes of parasites that infect/infest humans:

  1. Protozoan parasites – microscopic, single-celled organisms such as the Plasmodium parasites that cause malaria;
  2. Helminths (or worms) – multicellular organisms such as the tapeworms that can live in the digestive tracts of humans and animals; and
  3. Ectoparasites – arthropods that live on the body’s surface, such as ticks.

Parasites have an enormous impact on human and animal health – causing morbidity and mortality and a substantial economic burden. However, parasites are not all bad. The study of parasites is (i) revealing unique biological mechanisms evolved to allow an organism to thrive in or on another; (ii) ways to combat parasites to improve human and animal health; and even (iii) ways to harness the beneficial properties of parasites.

What is a parasite'A parasite is an organism that lives in or on an organism of another species (its host) and benefits by deriving nutrients at the other's expense'. Tunan (Nicole) Yu was surprised to find this definition was not as clear-cut as she expected. Read more in this blog post.


 The Good, the Bad & The Ugly parasite poster


The Good

Most people do not think of parasites as being good or beneficial, but the truth is, they play a vital role to the ecosystem, and we as humans even seek out their services from time to time.

» Read more about 'The Good' parasites.

The Bad

Parasites wreak havoc on humans. The parasitic disease malaria, for example, claims hundreds of thousands of lives annually and exacts a substantial economic burden.

» Read more about 'The Bad' parasites.

The Ugly

There is a whole world of parasites out there whose lifestyles are fascinating, diabolical, bizarre, or just plain ugly.

» Read more about 'The Ugly' parasites.

This National ScienceWeek 2021 site is supported by
 The Australian National University and The Australian Society for Parasitology 
The ANU Parasitology students acknowledge funding from SEEF (Student Extracurricular Enrichment Fund).  

ASP logoSEEF logo   Parasitologists contributing to this site: Jeremy Dubrulle, Margot Schneider, Samantha Shippley, Tunan (Nicole) Yu (undergraduate students), Soraya Zwahlen and Cibelly Goulart (van Dooren group), Merryn Fraser (Maier group), Sarah Shafik and Sashika Richards (Martin group) and Melanie Rug (Centre for Advanced Microscopy), and Geil van Dooren, as well as Christina Spry (Saliba group) and Alex Maier, who worked with Sharyn Wragg (webmaster) to put the site together.