Long-term determinants of the seroprevalence of Toxoplasma gondii in a mixed ungulate community

Authors: BARROSO, PATRICIA - University Of Castilla-La Mancha(UCLM); GARCIA-BOCANEGRA, IGNACIO - Universidad De Cordoba; ACEVEDO, PELAYO - University Of Castilla-La Mancha(UCLM); PALENCIA, PABLO - University Of Castilla-La Mancha(UCLM); CARRO, FRANCISCO - Consejo Superior De Investigaciones Cientificas (CSIC); JIMINEZ-RUIZ, SAUL - University Of Castilla-La Mancha(UCLM); ALMERIA, SONIA - US Department Of Health And Human Services (HHS); Dubey, Jitender; CANO-TERRIZA, DAVID - Universidad De Cordoba; VICENTE, JOAQUIN - University Of Castilla-La Mancha(UCLM)

Submitted to: Animals
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/7/2020
Publication Date: 12/9/2020
Citation: Barroso, P., Garcia-Bocanegra, I., Acevedo, P., Palencia, P., Carro, F., Jiminez-Ruiz, S., Almeria, S., Dubey, J.P., Cano-Terriza, D., Vicente, J. 2020. Long-term determinants of the seroprevalence of Toxoplasma gondii in a mixed ungulate community. Animals. 10(12):2349. https://doi.org/10.3390/ani10122349.
DOI: https://doi.org/10.3390/ani10122349

Interpretive Summary: Wildlife species can serve as useful sentinels informing us of the degree to which the environment is contaminated with pathogens that threaten livestock and human health. In a long-term collaboration completed prior to USDA’s recent programmatic redirection, ARS researchers assisted an investigation that documented that approximately one-third of wildlife (wild boar, deer, and other ungulates) were infected by the zoonotic parasite Toxoplasma gondii in a national park in Spain. Prevalent infections in those animals suggests widespread exposure, which indicates the need for vigilance in protecting livestock and human health. These results will be of interests to veterinarians, livestock producers, parasitologists and public health workers. This research was completed before redirection of Toxoplasma research at ARS.

Technical Abstract: Toxoplasma gondii is a worldwide spread obligate intracellular protozoan which infects warm-blooded vertebrates, including humans. In the present study, the epidemiology of T. gondii was studied in the ungulate host community (wild and domestic) of Doñana National Park (DNP, south-western Spain) for 13 years (2005-2018). We assessed several factors which potentially operate in the medium and long-term (environmental features, population and stochastic factors). Overall, the wild ungulate host community of DNP showed high seroprevalence values of T. gondii (STG; %± confidence interval (CI) 95%; wild boar Sus scrofa 39±3.3, n=698; red deer Cervus elaphus 30.7±4.4, n= 423; fallow deer Dama dama 29.7±4.2, n=452; and cattle 12.3±3.8, n=292). The complex interplay of hosts and ecological/epidemiological niches, together with the optimal climatic conditions for the survival of the oocysts that converge in this area, may favor the spread of the parasite in its host community. The temporal evolution of STG oscillated considerably, mostly in deer species. The relationships evidenced by statistical models indicated that a number of factors of different nature determined species patterns. Concomitance of effects among species, especially wild ungulates, indicated that relevant drivers of risk operated at community level. Our focus, addressing factors operating at broad temporal scale, allows evidencing their impacts on the epidemiology of T. gondii and its trends. This approach is key to understanding the epidemiology and ecology to T. gondii infection in wild host communities, and particularly at their interfaces with livestock and humans, in a context where the decline in seroprevalence leads to loss of immunity in humans.