Skip to main content
ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Parasitic Diseases Laboratory » Research » Publications at this Location » Publication #383046

Research Project: Detection and Control of Foodborne Parasites for Food Safety

Location: Animal Parasitic Diseases Laboratory

Title: Recent epidemiologic, clinical, and genetic diversity of Toxoplasma gondii infections in marsupials

item Dubey, Jitender
item MURATA, FERNANDO - Non ARS Employee
item Kwok, Oliver
item SU, CHUNLEI - University Of Tennessee
item GRIGG, MICHAEL - National Institutes Of Health (NIH)

Submitted to: Parasites & Vectors
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2021
Publication Date: 6/5/2021
Publication URL:
Citation: Dubey, J.P., Murata, F., Cerqueira-Cezar, C., Kwok, O.C., Su, C., Grigg, M. 2021. Recent epidemiologic, clinical, and genetic diversity of Toxoplasma gondii infections in marsupials. Parasites & Vectors. 14:301.

Interpretive Summary: Interpretive summary Toxoplasmosis is a worldwide zoonosis. The USDA provided the veterinary, clinical, and public health communities an indispensable resource by disseminating up to date scientific information on toxoplasmosis and its prevention. Humans become infected mostly by ingesting food and water contaminated with oocysts or by eating infected under cooked meat. Among many hosts of Toxoplasma, marsupial from Australia and New Zealand (kangaroos) are the most susceptible hosts of T. gondii. Kangaroos imported from Australia in USA and other countries continue to die of toxoplasmosis. This paper reviews literature from the past decade, including but not limited to scientific discoveries made by USDA scientists. No experiments or surveys were performed since the redirection of USDA’s program on toxoplasmosis.

Technical Abstract: Background: Toxoplasma gondii infections are common in humans and animals worldwide. Among all intermediate hosts of T. gondii, captive marsupials (referred here as kangaroos) from Australia and New Zealand are the most susceptible to clinical toxoplasmosis. However, free range marsupials can survive T. gondii infection. Infected kangaroo meat may serve as a source of T. gondii infection for humans. Differences in mortality patterns in different species of kangaroos and other marsupials is not fully understood. Lifestyle, habitat, and genetic characteristics of T. gondii are some of the risk factors. For example, koalas are rarely exposed to T. gondii because they live on tree-tops whereas wallabies are highly susceptible. Methods: The present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, and genetic diversity of T. gondii infecting in kangaroos in their native habitat and in exported animals. The role of genetic types of T. gondii and clinical disease is discussed. Results and discussion: Fatal toxoplasmosis was diagnosed in captive macropods in Argentina, Chile, China, Germany, Hungary, Japan, Spain, Turkey, and the USA. Most deaths occurred due to disseminated toxoplasmosis. Genetic characterization of DNA from viable T. gondii revealed atypical nonclonal genotypes. Fatal toxoplasmosis was also diagnosed in free range vombats (Vombatus ursinus) in Australia. Genetic characterization of DNA directly from host tissues of subclinical culled kangaroos at slaughter revealed atypical genotypes of T. gondii. Conclusion: Kangaroos in their native land, Australia and New Zealand have high prevalence of T. gondii and kangaroo meat can be a source of infection for humans if consumed uncooked/undercooked.