隐孢子虫和贾第鞭毛虫是腹泻的主要原因，它们经常在中国的蔬菜上发现。对于免疫受损的人，包括癌症患者，它们构成健康风险。针对中国数据进行的定量微生物风险评估评估了来自于将地表水和化粪池污水进行农业用途的隐孢子虫和贾第鞭毛虫暴露的风险。针对城市和农村地区的癌症患者和免疫竞争力强的人群的农业生产消费（顾客）和农业实践（农民）的暴露被考虑，并建立了风险缓解方案。对于免疫竞争力强的人，隐孢子虫和贾第鞭毛虫引起的累积疾病负担分别为每人每年9.68×10-6和5.57×10-5个伤残调整生命年（DALYs pppy），对于癌症患者分别为每人每年3.14×10-5和1.51×10-4 DALYs pppy。癌症患者的疾病负担约为免疫竞争力强的人的三倍。消费者的疾病负担高于农民，农村地区高于城市地区（均超过世界卫生组织推荐的最大值）。人口众多的省份，如河南、广东和四川的负担最重，而人畜粪便污水的负担高于地表水灌溉。在研究的三种蔬菜中，生菜的风险最大，其次是白菜，黄瓜的风险最小。风险缓解情景分析显示，在试图减轻疾病负担时，应考虑对地表水和粪便进行预处理，以及对蔬菜进行适当的收获后处理，包括消毒、烹饪和充分的表面热处理（75°C/60 s）。本研究的方法和结果有助于评估和减轻与农业灌溉和施肥实践相关的隐孢子虫和贾第鞭毛虫感染的负担，特别是对于癌症患者。 版权所有©2023 Elsevier Ltd.

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.Copyright © 2023 Elsevier Ltd. All rights reserved.