Research

CLAWS is very proud to be supporting PhD research candidate Annabel Park and her research with the University of Western Australia (UWA) investigating the prevalence of Toxoplasma gondii in the Great Southern Region.

Taking a One Health approach to Toxoplasma gondii infection

Background

Toxoplasma gondii is a widespread parasite that infects virtually all warm-blooded animals. T. gondii can only sexually reproduce in cats, who excrete the parasite into the environment through their faeces (Frenkel et al. 1970). Host animals can become infected by consuming contaminated soil or water, by ingesting tissue from infected animals or through vertical transmission from an infected female animal to its offspring (Hill and Dubey 2002). Infections of T. gondii in people range in severity. Most infections are asymptomatic, but the parasite can cause a disease known as toxoplasmosis, which can cause fatality in immunocompromised patients (Wang et al. 2017). Toxoplasmosis is also a concern for pregnant women, as infection can be passed on in utero, causing miscarriage or babies being born with vision loss, epilepsy or developmental delays (Bollani et al. 2022; Li et al. 2014). Livestock can become infected with T. gondii, and this is a particular concern in sheep as infection can cause abortion, still-birth and neonatal mortality (Dubey 2009), resulting in economic losses for farmers and the industry (Legge et al. 2020). T. gondii infection has been recorded in free-ranging populations of Australian native fauna species but it remains unclear if this is contributing to population declines (Hillman et al. 2016). T. gondii infection is a health concern for both people and animals so it is important to build understanding of the prevalence of T. gondii in different host species and examine the transmission of the parasite between them. Most studies on T. gondii infection investigate only one host species. There is value in taking a ‘One Health’ approach to T. gondii infection, that considers the interdependent health of people, animals and our shared environment in addressing the issue (Aguirre et al. 2019).

Approach

This project aims to take a One Health approach to Toxoplasma gondii infection in native wildlife, cats, livestock and people in the Great Southern Region. Some key questions we are interested in answering include:

1) Is there variation in the prevalence of T. gondii between feral, stray and owned cats?

2) Can free-ranging native mammal species survive T. gondii infection?

3) Is there variation in the prevalence of T. gondii between different native mammal species?

4) What is the prevalence of T. gondii in livestock?

5) What is the prevalence of T. gondii in people occupationally exposed to cats?

6) How does the prevalence of T. gondii in cats, wildlife, livestock and people in the Great Southern Region compare?

To answer these questions, blood samples will be collected from cats, wildlife, livestock and people in the Great Southern region and tested for T. gondii infection. A One Health framing prioritises an interdisciplinary approach to addressing health concerns, and accordingly this project will be one of collaboration between ecologists, researchers, farmers, invasive species managers, veterinarians, and the community.

This research is supported by Cat Laws and Wildlife Survival Working Group, the Department of Biodiversity, Conservation and Attractions, the University of Western Australia and an Australian Government Research Training Program (RTP) Scholarship. If you have any questions or would like to get involved, please contact PhD Researcher, Annabel Park (annabel.park@research.uwa.edu.au).

References

Aguirre, A. A., Longcore, T., Barbieri, M., Dabritz, H., Hill, D., Klein, P. N., Lepczyk, C., Lilly, E. L., McLeod, R., Milcarsky, J., Murphy, C. E., Su, C., VanWormer, E., Yolken, R., & Sizemore, G. C. (2019). The One Health Approach to Toxoplasmosis: Epidemiology, Control, and Prevention Strategies. EcoHealth, 16(2), 378–390. https://doi.org/10.1007/s10393-019-01405-7

Bollani, L., Auriti, C., Achille, C., Garofoli, F., De Rose, D. U., Meroni, V., Salvatori, G., & Tzialla, C. (2022). Congenital Toxoplasmosis: The State of the Art. Frontiers in Pediatrics, 10. https://doi.org/10.3389/fped.2022.894573

Dubey, J. P. (2009). Toxoplasmosis in sheep—The last 20 years. Veterinary Parasitology, 163(1), 1–14. https://doi.org/10.1016/j.vetpar.2009.02.026

Frenkel, J. K., Dubey, J. P., & Miller, N. L. (1970). Toxoplasma gondii in Cats: Fecal Stages Identified as Coccidian Oocysts. Science, 167(3919), 893–896. https://doi.org/10.1126/science.167.3919.893

Hill, D., & Dubey, J. P. (2002). Toxoplasma gondii: Transmission, diagnosis and prevention. Clinical Microbiology and Infection, 8(10), 634–640. https://doi.org/10.1046/j.1469-0691.2002.00485.x

Hillman, A. E., Lymbery, A. J., & Thompson, R. C. A. (2016). Is Toxoplasma gondii a threat to the conservation of free-ranging Australian marsupial populations? International Journal for Parasitology: Parasites and Wildlife, Including Articles from the 25th WAAVP Conference, Liverpool, August 2015, 5(1), 17–27. https://doi.org/10.1016/j.ijppaw.2015.12.002

Legge, S., Taggart, P. L., Dickman, C. R., Read, J. L., & Woinarski, J. C. Z. (2020). Cat-dependent diseases cost Australia AU$6 billion per year through impacts on human health and livestock production. Wildlife Research, 47(8), 731–746. https://doi.org/10.1071/WR20089

Li, X.-L., Wei, H.-X., Zhang, H., Peng, H.-J., & Lindsay, D. S. (2014). A Meta Analysis on Risks of Adverse Pregnancy Outcomes in Toxoplasma gondii Infection. PLOS ONE, 9(5), e97775. https://doi.org/10.1371/journal.pone.0097775

Wang, Z.-D., Liu, H.-H., Ma, Z.-X., Ma, H.-Y., Li, Z.-Y., Yang, Z.-B., Zhu, X.-Q., Xu, B., Wei, F., & Liu, Q. (2017). Toxoplasma gondii Infection in Immunocompromised Patients: A Systematic Review and Meta-Analysis. Frontiers in Microbiology, 8. https://doi.org/10.3389/fmicb.2017.00389