One of the largest fields in parasitology, medical parasitology is the study of those parasites which infect humans. These include organisms such as:
- Plasmodium spp., the protozoan parasite which causes malaria. The four species of malaria parasites infective to humans are Plasmodium falciparum,Plasmodium malariae, Plasmodium vivax & Plasmodium ovale.
- Leishmania donovani, the unicellular organism which causes leishmaniasis
- multicellular organisms such as Schistosoma spp., Wuchereria bancrofti and Necator americanus
- Lucilia sericata, a blowfly, which lays eggs on the skins of farm animals. The maggots hatch and burrow into the flesh, distressing the animal and causing economic loss to the farmer
- Otodectes cynotis, the cat ear mite, responsible for Canker.
- Gyrodactylus salaris, a monogenean parasite of salmon, which can wipe out populations which are not resistant.
Parasites exhibit an aggregated distribution among host individuals, thus the majority of parasites live in the minority of hosts. This feature forces parasitologists to use advanced biostatistical methodologies.
This is the study of structures of proteins from parasites. Determination of parasitic protein structures may help to better understand how these proteins function differently from homologous proteins in humans. In addition, protein structures may inform the process of drug discovery.
Parasites can provide information about host population ecology. In fisheries biology, for example, parasite communities can be used to distinguish distinct populations of the same fish species co-inhabiting a region. Additionally, parasites possess a variety of specialized traits and life-history strategies that enable them to colonize hosts. Understanding these aspects of parasite ecology, of interest in their own right, can illuminate parasite-avoidance strategies employed by hosts.
Taxonomy and phylogenetics
The huge diversity between parasitic organisms creates a challenge for biologists who wish to describe and catalogue them. Recent developments in using DNA to identify separate species and to investigate the relationship between groups at various taxonomic scales has been enormously useful to parasitologists, as many parasites are highly degenerate, disguising relationships between species.