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

Authors

Sophie Zhu, University of California, DavisFollow
Elizabeth VanWormer, University of Nebraska - LincolnFollow
Karen Shapiro, University of California, DavisFollow

ORCID IDs

Sophie Zhu https://orcid.org/0000-0002-8694-4058

Document Type

Article

Date of this Version

2023

Citation

Zhu S, VanWormer E, Shapiro K (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. PLoS ONE 18(6): e0286808. https://doi.org/ 10.1371/journal.pone.0286808

Comments

© 2023 Zhu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License,

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.