Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 1/26/2018
Publication Date: 1/26/2018
Citation: Hill D.E., Dubey J.P. (2018) Toxoplasma gondii. In: Ortega Y., Sterling C. (eds) Foodborne Parasites. Food Microbiology and Food Safety. Springer, Cham. https://doi.org/10.1007/978-3-319-67664-7_6.
Interpretive Summary: Toxoplasmosis, caused by Toxoplasma gondii, is one of the most common parasitic infections of humans and other warmblooded animals. It has been found worldwide, and nearly one third of humans have been exposed to the parasite. Congenital infection occurs when a woman becomes infected during pregnancy and transmits the parasite to the fetus. Besides congenital infection, humans become infected by ingesting food or water contaminated with sporulated oocysts from infected cat feces or through ingestion of tissue cysts in undercooked or uncooked meat. Food animals (pigs, chickens, lambs and goats) become infected by the same routes, resulting in meat products containing tissue cysts, which can then infect consumers. Toxoplasma infection is common in food animals in the United States. Implementation of animal management factors, such as biosecure confinement housing, are important in reducing the levels of infection in animals destined for human consumption.
Technical Abstract: Toxoplasma gondii is a coccidian parasite with an unusually wide range of intermediate hosts. Felids serve as definitive hosts and produce the environmentally resistant oocyst stage. Toxoplasma is one of the most common parasitic infections of man, though its prevalence varies widely from place to place. Toxoplasmosis continues to be a significant public health problem in the United States, where 8-22% of people are infected; a similar prevalence is seen in the United Kingdom. In Central America, South America and continental Europe, estimates of infection range from 30 to 90%. Most infections in humans are asymptomatic, but at times the parasite can produce devastating disease. Infection may be congenitally or post-natally acquired. In the United States, nationwide serological surveys demonstrated that seroprevalence in people remained stable at 23% from 1990 until 1998, while recent surveys have demonstrated a significant decrease in seroprevalence to 10.8% over the last decade. Similar decreases in seroprevalence have been observed in many European countries. It is estimated that 1,075,242 persons are infected with T. gondii each year in the U.S., and approximately 2,839 persons develop symptomatic ocular disease annually. The cost of illness in the United States caused by Toxoplasma has been estimated to be nearly 3 billion dollars and an 11,000 quality-adjusted life year (QALY) loss annually. Recent publications have linked suicide and schizophrenia to Toxoplasma infection.