# Food and Drinking Water as Sources of Pathogenic Protozoans: An Update
## 4 _Cryptosporidium_ spp.
### Cryptosporidium _spp. in Food_
In spiking experiments, it was observed that even vigorous washing with a detergent did not completely remove _Cryptosporidium_ oocysts from the apple surface and these retained their infectivity for at least 4 weeks, so drinking unpasteurized apple juice can expose to the risk of cryptosporidiosis [132]. Fresh produce, washed or unwashed, was not identified as a risk factor [121; 128] despite being the principal source of foodborne cryptosporidiosis outbreaks [89; 100; 113; 127; 133]. Indeed, several case-control studies suggested that vegetable consumption might lead to the acquisition of immunity following repeated exposure to low doses of oocysts [121; 128]. Moreover, eating chicken and hard cheese was suggested to protect from _Cryptosporidium_ infection [121]. Nevertheless, in a study in Ghana, not regularly washing vegetables was found to be significantly associated with the prevalence of cryptosporidiosis in HIV-infected patients [134]. In addition, in Sweden, cases of cryptosporidiosis peaked in 2019 and 2022, due mostly to outbreaks caused by leafy greens [100]. _Cryptosporidium_ spp. contamination was detected in 6% vegetables and fruits sampled in Norway, most often in mung bean sprouts, in 5% vegetable samples from an area of high livestock production in Poland, in 5% of cilantro leaves, 8.7% cilantro roots, 2.5% lettuce, 1.2% in radish, tomato, cucumbers, and carrot samples in Costa Rica, and 5.9% ready-to-eat packaged leafy greens in Canada. Contamination rates in Peru were 8.5%, 14.5%, and 19.35% for pooled vegetable samples collected in three sampling periods in markets. In African countries, 35% of vegetable samples were found to be contaminatedin Kaduna State, Nigeria; between 11.7% (green onion) and 46.7% (rocket) in Egypt; and 16% in the Accra Metropolis, Ghana, with vegetables sold in open-air markets showing a 10 times higher contamination level than those from supermarkets for possible unhygienic handling. _C. parvum_ was detected in all the studies performing species identification [127]. Cryptosporidiumup. occurrence was also observed in fish and seafood, which could thus represent an infection route. The first epidemiological study on _Cryptosporidium_ spp. in edible marine fish was carried out in seas surrounding France and found an overall prevalence of 2.3% and 3.2% in two sampling periods, respectively. _C. parvum_ subtypes IIaA13G1R1, IIaA15G2R1, IIaA17G2R1, and IIaA18G3R1, and eight genotypes closely related to _C. molnari_ were detected. Saithe fish showed the highest prevalence (19%), but positive samples were also found for cod, ling, mackerel, sardine, anchovy, hake, and herring. A higher prevalence of _Cryptosporidium_ spp. was observed in larger fishes during the spring-summer period in the northeast Atlantic [135]. In the western Mediterranean region, samples positive for _Cryptosporidium_ spp. were found among synanthropic fish from all four farms examined, and in cultivated sardinellas, European seabass, Mediterranean horse mackerel, blotched picarel, and pompano from three of the farms. The only positive fish from the extractive fisheries was a bogue. The identified species were _C. molnari_, the zoonotic _C. ubiquitin_, able to affect a wider range of hosts compared with other species, _C. scophthalmi_, and one isolate highly divergent from known species/genotypes. _Cryptosporidium_ spp. was also detected in fish fillets possibly for cross-contamination during evisceration [136]. In shellfish aquaculture sites on Thailand's Gulf Coast, 13.8% of oyster samples were contaminated by _Cryptosporidium_ species [137]. Therefore, fish and seafood consumed raw or undercooked can represent a risk for cryptosporidiosis.