More people, more cats, more parasites: Human population density predicts the prevalence of Toxoplasma gondii oocyst shedding in free-ranging domestic and wild felids
Zhu, Sophie (2023), More people, more cats, more parasites: Human population density predicts the prevalence of Toxoplasma gondii oocyst shedding in free-ranging domestic and wild felids, Dryad, Dataset, https://doi.org/10.25338/B8H63B
Aim: 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. Risk factors for oocyst shedding are well-documented in domestic cats under controlled settings, but 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 aimed to determine how climate and anthropogenic factors influence the level of oocyst shedding in free-ranging domestic cats and wild felids.
Time period: 1973-2021
Major taxa studied: Felidae, Toxoplasma gondii
Methods: We used generalized linear mixed models to determine the association between climatic, ecological, and anthropogenic factors and T. gondii oocyst shedding in free-ranging felids. T. gondii oocyst shedding data from 48 studies were compiled for domestic cats and 12 wild felid species, encompassing 256 positive samples out of 9,635 total fecal samples.
Results: T. gondii shedding prevalence in domestic cats and wild felids was positively associated with human population density at the sampling location. Average annual temperature and total precipitation were not associated with increased shedding, however, temperature variables that reflected fluctuation on a smaller timescale were associated with oocyst shedding. Larger mean diurnal range was associated with higher T. gondii oocyst shedding prevalence in domestic cats, while higher temperatures in the driest quarter were associated with lower oocyst shedding in wild felids.
Main conclusions: Anthropogenic factors associated with increasing human population density and climate change in the form of temperature fluctuation can exacerbate environmental contamination with the protozoan parasite T. gondii. Direct or indirect management of free-ranging domestic cats could lower the burden of environmental oocysts due to their large population sizes and close affinity with human settlements.
Dataset was collected using systematic review.