Detection of Cryptosporidium and Giardia in foods of plant origin in North-Western Greece

Cryptosporidium and agriculture: A review

Cryptosporidiosis is a significant contributor to global foodborne and waterborne disease burden. It is a widespread cause of diarrheal diseases that affect humans and animals worldwide. Agricultural environments can become a source of contamination with Cryptosporidium species through faecal material derived from humans and animals. This review aims to report the main findings of scientific research on Cryptosporidium species related to various agricultural sectors, and highlights the risks of cryptosporidiosis in agricultural production, the contamination sources, the importance of animal production in transmission, and the role of farmed animals as hosts of the parasites. Agricultural contamination sources can cause water pollution in groundwater and different surface waters used for drinking, recreational purposes, and irrigation. The application of contaminated manure, faecal sludge management, and irrigation with inadequately treated water are the main concerns associated with foodborne and waterborne cryptosporidiosis related to agricultural activities. The review emphasizes the public health implications of agriculture concerning the transmission risk of Cryptosporidium parasites and the urgent need for a new concept in the agriculture sector. Furthermore, the findings of this review provide valuable information for developing appropriate measures and monitoring strategies to minimize the risk of infection.

Health risks of Cryptosporidium and Giardia in the application of surface water and septic tank effluent in Chinese agriculture: Impact on cancer patients identified by quantitative microbial risk assessment

The protozoa Cryptosporidium and Giardia are major causes of diarrhea and are commonly found on vegetables in China. They pose a health risk, particularly to immunocompromised individuals, including cancer patients. A quantitative microbial risk assessment of Chinese data evaluated the risks of Cryptosporidium and Giardia exposure arising from the application of surface water and septic tank effluent to agricultural land. Exposure via agricultural produce consumption (consumers) and agricultural practices (farmers) was considered for subpopulations of cancer patients and immunocompetent people in urban and rural areas, and risk mitigation scenarios were modelled. The cumulative disease burdens attributable to cryptosporidiosis and giardiasis were, respectively, 9.68×10^-6 and 5.57×10^-5 disability-adjusted life years per person per year (DALYs pppy) for immunocompetent people, and 3.14×10^-5 and 1.51×10^-4 DALYs pppy for cancer patients. Cancer patients were approximately three times more likely to have an individual disease burden than immunocompetent people. The disease burden was higher for consumers than farmers, and higher in rural areas than urban areas (all exceeding the maximum recommended by the World Health Organization). The highest burdens were in provinces of high population, such as Henan, Guangdong, and Sichuan, while the burden associated with human and livestock fecal effluent application was higher than with surface water irrigation. Of the three vegetables studied, lettuce posed the greatest risk, followed by bok choy, while cucumber posed the least risk. Risk mitigation scenario analysis showed that pre-treatment of surface water and feces, and appropriate post-harvest handling of vegetables, including disinfection, cooking, and adequate surface heat treatment (75 °C for 60 s), should be considered when attempting to reduce disease burdens. The methodology and findings of this study are useful for evaluating and reducing the burden of Cryptosporidium and Giardia infections associated with agricultural irrigation and fertilization practices, particularly on cancer patients.

Protozoan Parasites and Leafy Greens in Marrakech: Study of Occurrence Using a Molecular Method

PURPOSE

The aim of this study was to assess the presence of T. gondii, Cryptosporidium spp. oocysts, and G. duodenalis cysts, in three leafy greens (coriander, lettuce, and parsley) commonly consumed raw. Despite the recognition of the association between the parasitic illnesses and the consumption of contaminated food, there is still a lack of studies investigating the occurrence of parasitic contamination in food matrices.

METHODS

A total of 152 leafy green samples were collected in Marrakech from April 2018 to October 2019. Parasites were eluted and concentrated before detection of their DNA by real-time qPCR.

RESULTS

The analysis revealed an overall rate of contamination of 32.2% (49/152), with 29.6% (45/152) positive for T. gondii and 2.6% (4/152) for G. duodenalis, while none was positive for Cryptosporidium spp.

CONCLUSION

The results showed that humans can be exposed to protozoan parasites through vegetables consumption. Further investigations can be performed to acquire new epidemiological data to assess the public health impact of these protozoan diseases in Morocco.