# Food and Drinking Water as Sources of Pathogenic Protozoans: An Update
## 6 _Toxoplasma gondii_
### Involvement of Food and Drinking Water in T. gondii Infections  
Brazil has one of the highest rates of _T. gondii_ infection, and the severity of toxoplasmosis in congenitally infected children is considered to be the highest in the world. Outbreak notification and epidemiological investigations are compulsory in the country and, among 35 outbreak reports published worldwide since 1967, most were from Brazil. The main transmission routes were water, vegetables, fruits, raw or undercooked meats, and unpasteurized goat's milk. The largest outbreak ever registered occurred in 2018 and affected more than 900 persons in Santa Maria, Rio Grande do Sul Municipality. The outbreak investigation began when physicians reported increased cases of a syndrome characterized by fever, mylgia, headache, rash, and mild gastrointestinal and respiratory symptoms. Pregnant women represented 15% of cases, and 3 fetal deaths, 9 abortions and 28 cases of congenital toxoplasmosis occurred. Drinking water was the source of infection, as ascertained by bioassay in piglets and mice carried out with the contaminated water. The necessity of continuous monitoring of public water supplies for _T. gondii_ contamination emerged [168]. A recent outbreak of acute toxoplasmosis involved 73 employees of an institution over 4 months and a case-control investigation revealed a significant association of cases with eating raw salad at the institution's restaurant [169]. In June 2016, acute toxoplasmosis cases were reported in Montes Claros de Goias, Brazil, with symptoms including fever, lymphadenomegaly, ophthalmic alteration, seizure, and mylalgia. Since vegetables and artisan fresh cheese from raw cow's milk were consumed by 100.0% and 78.6% of the involved patients, respectively, these sources were evaluated in a case-control study. The consumption of artisan fresh cheese from raw cow's milk was found to be the only significant variable, and two samples of artisan fresh cheese and one irrigation water sample tested positive for _T. gondii_ by PCR. One of the inspected cheese manufacturers presented an inadequate factory structure, allowing access to cats, which were probably the source of the parasite [170]. In a systematic review and meta-analysis on seroprevalence of _T. gondii_ in pregnant women in eighteen countries of the WHO Eastern Mediterranean region, a pooled prevalence of 36.5% was found. From the studies that examined foodborne transmission, it emerged that 32.9% of positive women drank unprocessed milk, 43.7% at raw or undercooked meat, and 40.8% ate unwashed raw vegetables [164]. Based on the determination of antibodies against _T. gondii_ IgM, unpasteurized milk consumption was found to be a major risk factor for infection in a case-control study comparing women of childbearing age with a previous history of recurrent pregnancy loss and controls in the province of Khyber Pakhtunkhwa, Pakistan [171]. Multiple outbreaks and cases of toxoplasmosis have been reported recently and also regarded immunocompetent individuals, including hunters who consumed undercooked venison in Wisconsin, USA. An atypical genotype (haplogroup 12, polymerase chain reaction restriction fragment length polymorphism genotype 5) common in North America was isolated and characterized for the first time for human clinical manifestations [172]. In a case-control study in the Netherlands, it was found that in the cases ascertained by fourteen regional medical laboratories consumed beef, veal, and raw/undercooked beef such as steak, steak tartare, and roast beef more frequently than the controls in the nine months preceding the analysis. Consumption of lamb, duck/goose, big game animals, undercooked pork prepared as raw bacon, spreadable sausages, toppings, raw or undercooked crustaceans, and shellfish was more often reported by cases. After adjustment for age, gender, and pregnancy, two factors remained as risk factors, i.e., consumption of meat from large game animals and washing hands occasionally or never before preparing food.