Among numerous challenges facing space travellers, microbial infection is one of the unknown risks associated with human spaceflight. Prevention and control of microbial infections are of critical concern during space missions. The objective of this research is to develop a quantitative microbial risk assessment (QMRA) to model the risk of Staphylococcus aureus skin infection and mitigation strategies that may effectively reduce skin infection risks. QMRA was carried out by incorporating the level of S. aureus contamination from International Space Station Microbial Observatory Experiment, bacterial transfer rate to skin, growth pattern of S. aureus on skin, space travellers’ daily behaviour and dose-response model. The results demonstrate that a daily skin cleaning regimen has a significant effect on reducing the skin infection risks. Once a day skin cleaning reduces infection risk by 84.2% and twice a day skin cleaning can reduce the risk of skin infection by 96.1% during a seven-day space mission. Frequency of contact with contaminated surfaces and time elapsed between cleaning events are the most important input parameters that contribute to the overall risk outcome. There are degrees of uncertainties associated with the predicted outcomes when interpreted by itself due to the limitation of microbial data and the dose-response model that derived from a short-term clinical study on Earth. The comparative risk analysis as used in this study offers a scientific basis regarding the effectiveness of interventions (skin cleaning regimens) in mitigating skin infection risks during spaceflight.

在太空旅行者面临的众多挑战中，微生物感染是与人类太空飞行相关的未知风险之一。太空飞行期间，预防和控制微生物感染至关重要。这项研究的目的是开发一种定量微生物风险评估（QMRA），以对金黄色葡萄球菌皮肤感染的风险进行建模，并制定可有效降低皮肤感染风险的缓解策略。通过结合国际空间站微生物观测实验室的金黄色葡萄球菌污染水平，细菌向皮肤的转移率，金黄色葡萄球菌的生长方式来进行QMRA皮肤，太空旅行者的日常行为和剂量反应模型。结果表明，每日皮肤清洁方案对降低皮肤感染风险具有显著作用。每天一次的皮肤清洁可以在7天的太空任务中将感染风险降低84.2％，每天两次可以将皮肤感染的风险降低96.1％。与污染表面的接触频率以及两次清洁之间的间隔时间是影响总体风险结果的最重要的输入参数。由于微生物数据和源于地球的短期临床研究的剂量反应模型的局限性，当单独解释时，与预测结果相关的不确定性程度较高。