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. 2023 Jun 21;18(6):e0286808.
doi: 10.1371/journal.pone.0286808. eCollection 2023.

More people, more cats, more parasites: Human population density and temperature variation predict prevalence of Toxoplasma gondii oocyst shedding in free-ranging domestic and wild felids

Sophie Zhu  1 , Elizabeth VanWormer  2   3 , Karen Shapiro  1
Affiliations

More people, more cats, more parasites: Human population density and temperature variation predict prevalence of Toxoplasma gondii oocyst shedding in free-ranging domestic and wild felids

Sophie Zhu et al. PLoS One. .

Abstract

Toxoplasma gondii is a ubiquitous zoonotic parasite that can infect warm-blooded vertebrates, including humans. Felids, the definitive hosts, drive T. gondii infections by shedding the environmentally resistant stage of the parasite (oocysts) in their feces. Few studies characterize the role of climate and anthropogenic factors in oocyst shedding among free-ranging felids, which are responsible for the majority of environmental contamination. We determined how climate and anthropogenic factors influence oocyst shedding in free-ranging domestic cats and wild felids using generalized linear mixed models. T. gondii oocyst shedding data from 47 studies were systematically reviewed and compiled for domestic cats and six wild felid species, encompassing 256 positives out of 9,635 total fecal samples. Shedding prevalence in domestic cats and wild felids was positively associated with human population density at the sampling location. Larger mean diurnal temperature range was associated with more shedding among domestic cats and warmer temperature in the driest quarter was associated with lower oocyst shedding in wild felids. Increasing human population density and temperature fluctuation can exacerbate environmental contamination with the protozoan parasite T. gondii. Management of free-ranging domestic cats could lower the burden of environmental oocysts due to their large population sizes and affinity with human settlements.

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Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Map of confirmed T. gondii oocyst shedding prevalence in free-ranging domestic cats (red) and wild felid species (blue) in studies conducted from 1973–2021.
Modified from Zhu et al. 2021 [21] and included for illustrative purposes. Map created using ‘rnaturalearth’ package [34].
See this image and copyright information in PMC

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