A Quantitative Microbial Risk Assessment (QMRA) technique was applied to assess the public health risk from exposure to infectious microorganisms at bathing areas of three rivers in Bangladesh. The QMRA assessed the probability of illness due to the accidental ingestion of river water impacted by untreated sewage. The simplified QMRA was based on average concentrations of four reference pathogens Escherichia coli (E. coli) O157:H7, Cryptosporidium spp, norovirus and rotavirus relative to indicator bacterium E. coli. Public health risk was estimated as the probability of infection and illness from a single exposure of bathers. The risks of illness were ranged from 7 to 10% for E. coli O157:H7, 13 to 19% for Cryptosporidium, 7 to 10% for norovirus and 12 to 17% for rotavirus. The overall risk of illness at the rivers was slightly higher in children (9–19%) compared to adults (7–16%). The risks of illness in individuals exposed to the river bathing were unacceptably high, exceeding the USEPA acceptable risk of 3–6 illnesses per hundred bathing events. This study gives a basis for reducing the burden of disease in the population by applying appropriate risk management. Findings and methods of this study will be helpful for other countries with similar socio-economic and geographic settings.

应用了定量微生物风险评估（QMRA）技术来评估孟加拉国三条河流沐浴区暴露于传染性微生物引起的公共健康风险。QMRA评估了未经处理的污水对河水的意外摄入所致疾病的可能性。简化QMRA是基于平均浓度四个参考病原体大肠杆菌（大肠杆菌）O157：H7，隐孢子虫属，诺罗病毒和轮状病毒相对向指示菌大肠杆菌。公共健康风险被估计为单次沐浴者感染和患病的可能性。大肠杆菌O157：H7的疾病风险范围为7％至10％，大肠杆菌的水平为13％至19％隐孢子虫，对于诺如病毒为7至10％，对于轮状病毒为12至17％。儿童（9–19％）与成年人（7–16％）相比，河流患病的总体风险略高。暴露于河浴中的人患病的风险高得令人无法接受，超过了USEPA可接受的每100次沐浴事件中3–6种疾病的风险。该研究为通过应用适当的风险管理减轻人群疾病负担提供了基础。这项研究的结果和方法将对其他具有相似社会经济和地理环境的国家有所帮助。