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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Animal Parasitic Diseases Laboratory » Research » Publications at this Location » Publication #323791
Title: Quantifying the risk of human Toxoplasma gondii infection due to consumption of fresh pork in the United States

Author
item GUO, MIAO - University Of Maryland
item LAMBERTINI, ELISABETTA - University Of Maryland
item BUCHANAN, ROBERT - University Of Maryland
item Dubey, Jitender
item Hill, Dolores
item GAMBLE, H. RAY - National Academy Of Sciences - United States
item JONES, JEFFREY - Centers For Disease Control And Prevention (CDC) - United States
item PRADHAN, ABANI - University Of Maryland

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/20/2016
Publication Date: 10/21/2016
Citation: Guo, M., Lambertini, E., Buchanan, R.L., Dubey, J.P., Hill, D.E., Gamble, H., Jones, J.L., Pradhan, A.K. 2016. Quantifying the risk of human Toxoplasma gondii infection due to consumption of fresh pork in the United States. Food Control. 73:1210-1222.

Interpretive Summary: Toxoplasmosis caused by a single celled parasite, Toxoplasma gondii, continues to be a worldwide public health problem. Human toxoplasmosis accounts for an estimated one-fifth of all diagnosed foodborne infections in the United States, and one fifth of the economic costs attributable to any foodborne pathogen. Pregnant women and their fetuses are exposed to elevated health risks. The goal of this study was to develop a farm-to-table quantitative microbial risk assessment model to predict the public health risk associated with consumption of fresh pork in the United States. Approximately 957 new infections per year were estimated to occur in pregnant women, corresponding to 277 cases of congenital toxoplasmosis per year due to fresh pork ingestion. In the context of available data, sensitivity analysis suggested that cooking is the most important parameter impacting human health risk. This study provides a scientific basis for risk management and also could serve as a baseline model to quantify infection risk from T. gondii and other parasites associated with meat products. These results will be useful for veterinarians, parasitologists, immunologists, and epidemiologists interested in understanding transmission risks attributable to consumption of undercooked pork for toxoplasmosis.

Technical Abstract: Toxoplasma gondii is one of the leading foodborne pathogens in the United States. The Centers for Disease Control and Prevention (CDC) reported that T. gondii accounts for 24% of deaths due to foodborne illness in the United States. Consumption of undercooked pork products in which T. gondii has encysted has been identified as an important route of human exposure. However, little quantitative evaluation of risk due to different pork products as a function of microbial quality at the abattoir, during the production process, and due to consumer handling practices is available to inform risk management actions. The goal of this study was to develop a farm-to-table quantitative microbial risk assessment (QMRA) model to predict the public health risk associated with consumption of fresh pork in the United States. T. gondii prevalence in pigs was derived through a meta-analysis of existing data, and the concentration of the infectious life stage (bradyzoites) was calculated for each pork cut from an infected pig. Logistic regression and log-linear regression models were developed to predict the reduction of T. gondii during further processing and consumer preparation, respectively. An exponential mouse-derived dose-response model was used to predict infection risk in humans. The estimated mean probability of infection per serving of fresh pork products ranges from 3.2×10-7 to 9.5×10-6, corresponding to a predicted 94,606 new infections annually in the U.S. population due to fresh pork ingestion. Approximately 957 new infections per year were estimated to occur in pregnant women, corresponding to 277 cases of congenital toxoplasmosis per year due to fresh pork ingestion. In the context of available data, sensitivity analysis suggested that cooking is the most important parameter impacting human health risk. This study provides a scientific basis for risk management and also could serve as a baseline model to quantify infection risk from T. gondii and other parasites associated with meat products.