Toxoplasma gondii is an extremely serious parasite that is a leading cause of hospitalizations (fourth leading) and death (second only to Salmonella) from foodborne sources in the United States. There are 300 to 4,000 cases of congenital toxoplasmosis each year in the United States. The illness causes blindness, deafness, mental deficiencies, epilepsy and/or death in babies whose mothers contracted the parasite during pregnancy. T. gondii infects more than 800,000 people each year in the United States. Non-congenital symptoms can include blindness (3,600 per year), and in people who are immunocompromised, the illness can cause encephalitis, dementia, mental illness or death. While healthy adults can recover from the symptoms of toxoplasmosis, the parasite remains in their bodies and can be reactivated when they become immunocompromised. [CDC, 2011; Kotula, et al., 1991; CDC, 2021; FDA, 2018; Dubey, 1994] Approximately 50% of the cases of human toxoplasmosis in the U.S. each year are from food [FDA, 2018].
Toxoplasmosis is a worldwide problem, and the CDC estimates that 40 million people in the United States have T. gondii in their body [CDC, 2018]. Dubey placed the estimate at 30-40% of the adult U.S. population [Dubey, 1994] which is 98 to 131 million people) carry the parasite. Many other countries have higher, and much higher, percentages of infected people [Dubey and Beattie, 1988].