Quantitative Risk Assessment of Oocyst Versus Bradyzoite Foodborne Transmission of Toxoplasma gondii in Brazil

Authors

Sophie Zhu, University of California, Davis
Elizabeth VanWormer, University of Nebraska - LincolnFollow
Beatriz Martínez-López, University of California, Davis
Lílian Maria Garcia Bahia-Oliveira, Universidade Federal do Rio de Janeiro
Renato Augusto DaMatta, Universidade Estadual do Norte Fluminense
Pedro Souto Rodrigues, Universidade Estadual do Norte Fluminense
Karen Shapiro, University of California, Davis

Date of this Version

6-25-2023

Citation

Zhu, S.; VanWormer, E.; Martínez-López, B.; Bahia-Oliveira, L.M.G.; DaMatta, R.A.; Rodrigues, P.S.; Shapiro, K. Quantitative Risk Assessment of Oocyst Versus Bradyzoite Foodborne Transmission of Toxoplasma gondii in Brazil. Pathogens 2023, 12, 870. https:// doi.org/10.3390/pathogens12070870

Comments

Open access.

Abstract

Toxoplasma gondii is a globally distributed zoonotic protozoan parasite. Infection with T. gondii can cause congenital toxoplasmosis in developing fetuses and acute outbreaks in the general population, and the disease burden is especially high in South America. Prior studies found that the environmental stage of T. gondii, oocysts, is an important source of infection in Brazil; however, no studies have quantified this risk relative to other parasite stages. We developed a Bayesian quantitative risk assessment (QRA) to estimate the relative attribution of the two primary parasite stages (bradyzoite and oocyst) that can be transmitted in foods to people in Brazil. Oocyst contamination in fruits and greens contributed significantly more to overall estimated T. gondii infections than bradyzoite-contaminated foods (beef, pork, poultry). In sensitivity analysis, treatment, i.e., cooking temperature for meat and washing efficiency for produce, most strongly affected the estimated toxoplasmosis incidence rate. Due to the lack of regional food contamination prevalence data and the high level of uncertainty in many model parameters, this analysis provides an initial estimate of the relative importance of food products. Important knowledge gaps for oocyst-borne infections were identified and can drive future studies to improve risk assessments and effective policy actions to reduce human toxoplasmosis in Brazil.