Gastrointestinal illness refers to a broad range of diseases that affect the digestive system, including infections caused by bacteria, viruses, and parasites. Quantitative Microbial Risk Assessment (QMRA) is a powerful tool used to evaluate the risks associated with microbial pathogens in various environments. The main objective of this study was to conduct a quantitative assessment of gastrointestinal illnesses that occur as a result of exposure to and enterococci during recreational activities on the southern coasts of the Caspian Sea. Samples were collected from the recreational beaches along the border line of the Caspian Sea. The samples were analyzed for the presence and enumeration of and enterococci using the microplate method and membrane filtration techniques. Then, the annual and daily infection risks were computed using the Monte Carlo simulation approach. The results revealed that the risk of daily and annual infections on the coasts of Babolsar was higher than that on the coasts of Sari. Also, in the recreational waters of these beaches, the risk of infection by enterococci was higher than that posed by . In Babolsar, the average annual infection risk caused by and enterococci was 0.365 and 1 for children and 0.181 and 0.986 for adults. Also, in Sari, the average annual infection risk caused by and enterococci was 0.060 and 0.908 for children and 0.027 and 0.815 for adults. In addition, children were more likely than adults to become infected. In light of the study's findings, due to the entry of untreated urban wastewater into the southern part of the Caspian Sea (northern Iran) and the high risk of infectious diseases for children, more control and health measures are necessary for children's swimming.

中文翻译：

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里海南部海岸娱乐性接触大肠杆菌和肠球菌引起的胃肠道疾病的定量微生物风险评估

胃肠道疾病是指影响消化系统的一系列疾病，包括由细菌、病毒和寄生虫引起的感染。定量微生物风险评估（QMRA）是用于评估各种环境中微生物病原体相关风险的强大工具。本研究的主要目的是对里海南部海岸娱乐活动期间因接触肠球菌而发生的胃肠道疾病进行定量评估。样本是从里海边境线的休闲海滩采集的。使用微孔板方法和膜过滤技术分析样品中肠球菌的存在和计数。然后，使用蒙特卡罗模拟方法计算年度和每日感染风险。结果显示，巴博尔萨尔海岸每日和每年感染的风险高于萨里海岸。此外，在这些海滩的休闲水域中，感染肠球菌的风险高于感染肠球菌的风险。在巴博尔萨尔，儿童肠球菌引起的年平均感染风险分别为0.365和1，成人分别为0.181和0.986。此外，在萨里，儿童由肠球菌引起的年平均感染风险分别为 0.060 和 0.908，成人为 0.027 和 0.815。此外，儿童比成人更容易被感染。根据研究结果，由于未经处理的城市废水进入里海南部（伊朗北部），儿童感染传染病的风险较高，因此需要对儿童游泳采取更多控制和健康措施。