Skip to main content
Kent Academic Repository

Are molecular tools clarifying or confusing our understanding of the public health threat from zoonotic enteric protozoa in wildlife?

Robertson, Lucy J., Clark, Graham C., Debenham, John J., Dubey, J. P., Kvac, Martin, Li, Junqiang, Ponce-Gordo, Francisco, Ryan, Una, Schares, Gereon, Su, Chunlei, and others. (2019) Are molecular tools clarifying or confusing our understanding of the public health threat from zoonotic enteric protozoa in wildlife? International Journal for Parasitology: Parasites and Wildlife, 9 . pp. 323-341. ISSN 2213-2244. (doi:10.1016/j.ijppaw.2019.01.010) (KAR id:72566)


Emerging infectious diseases are frequently zoonotic, often originating in wildlife, but enteric protozoa are considered relatively minor contributors. Opinions regarding whether pathogenic enteric protozoa may be transmitted between wildlife and humans have been shaped by our investigation tools, and has led to oscillations regarding whether particular species are zoonotic or have host-adapted life cycles.

When the only approach for identifying enteric protozoa was morphology, it was assumed that many enteric protozoa colonized multiple hosts and were probably zoonotic. When molecular tools revealed genetic differences in morphologically identical species colonizing humans and other animals, host specificity seemed more likely. Parasites from animals found to be genetically identical - at the few genes investigated - to morphologically indistinguishable parasites from human hosts, were described as having zoonotic potential. More discriminatory molecular tools have now sub-divided some protozoa again. Meanwhile, some infection events indicate that, circumstances permitting, some “host-specific” protozoa, can actually infect various hosts. These repeated changes in our understanding are linked intrinsically to the investigative tools available.

Here we review how molecular tools have assisted, or sometimes confused, our understanding of the public health threat from nine enteric protozoa and example wildlife hosts (Balantoides coli - wild boar; Blastocystis sp. - wild rodents; Cryptosporidium spp. - wild fish; Encephalitozoon spp. - wild birds; Entamoeba spp. - non-human primates; Enterocytozoon bieneusi - wild cervids; Giardia duodenalis - red foxes; Sarcocystis nesbitti - snakes; Toxoplasma gondii - bobcats).

Molecular tools have provided evidence that some enteric protozoa in wildlife may infect humans, but due to limited discriminatory power, often only the zoonotic potential of the parasite is indicated. Molecular analyses, which should be as discriminatory as possible, are one, but not the only, component of the toolbox for investigating potential public health impacts from pathogenic enteric protozoa in wildlife.

Item Type: Article
DOI/Identification number: 10.1016/j.ijppaw.2019.01.010
Uncontrolled keywords: Emerging infection, Host specificity, Protozoa, Transmission, Wildlife, Zoonosis
Subjects: Q Science > QR Microbiology
Divisions: Divisions > Division of Natural Sciences > Biosciences
Depositing User: Anastasios Tsaousis
Date Deposited: 14 Feb 2019 17:32 UTC
Last Modified: 04 Jul 2023 13:42 UTC
Resource URI: (The current URI for this page, for reference purposes)

University of Kent Author Information

Tsaousis, Anastasios D.

Creator's ORCID:
CReDIT Contributor Roles:
  • Depositors only (login required):

Total unique views for this document in KAR since July 2020. For more details click on the image.