A question that is not so easy to answer. Let’s start with a common definition –

A parasite is an organism that lives in, or on, another organism and causes harm to that organism.

Assuming that every organism fulfilling the definition above is a parasite puts bacteria and viruses into the same level of organisation as protozoans, helminths and ticks. And anyone who works on any of these infections is a parasitologist. So describing myself as a parasitologist could mean I specialised in one or many of these organisms. This would be somewhat disingenous as my knowledge of bacteria and viruses, most protozoans and all pathogenic fungi is through scholarship (seeking knowledge, reading, writing, teaching) rather than research (seeking funding, investigating gaps in knowledge, writing inferences). Identity is important from every perspective – seeking funding, public engagement, publishing, reputation building, recruiting students, teaching etc. Getting it wrong can lead to lost oppportunities in all these domains.

Scientists in fact differentiate their area of research and scholarship speciality depending on whether they are interested in viruses (virologists), protozoans (protists), bacteria (bacteriologists) and helminths (helminthologists). Those specialising in ecto-parasites like ticks and mites are likely to belong to the domain of entomology. Microbiologist is a term also used by people working on viruses and bacteria and pathogenic fungi.

As a practicing researcher, I am in fact closest to helminthology as most of my research has been on helminth parasites. My first degree was in zoology, so I am also a zoologist. Much of that work focused on the biology of organisms, so I am also a biologist.

Within academic circles, describing myself as a helminthologist would not be a problem, except that that this term can be used by researchers specialising in any type of helminth (free living or parasitic). The Journal of Helminthology is an example of a journal that publishes on both forms.

Then we have the Neglected Tropical Diseases, an umbrella and ‘branding’ term that captures a wide range of infections including viruses, bacteria, protozoans, helminths, fungi and even snakebite. As my parasites of interest are included in this list I could also call myself whatever collective noun is applied to scientists and practitioners working on NTDs.

Like many other scientists my interests are contained in a handful of specific disciplines. Here I differentiate myself as an eco-epidemiologist because I am interested in public health and because I am interested in the population biology and ecology of infection.

So I am a parasitologist specialising in the ecology and epidemiology and population biology of parasitic helminths.

Or maybe a parasite epidemiologist specialising in helminth population biology and ecology…

Or perhaps a helminthologist specialising in the population biology and epidemiology of parasitic helminths.

What about a zoologist specialising in parasitic helminth population biology, ecology and epidemiology?

How about a helminth parasitologist specialising in the ecology and epidemiology of a group of Neglected Tropical diseases of great public health importance?

I like the last one, except I’ve also published on research into malaria. Better start again…