Rashid, HarunorHashim, Mahdi A2023-12-242023-12-242023-12-21https://hdl.handle.net/20.500.14154/70373Hajj and Umrah pilgrimages in the Kingdom of Saudi Arabia (KSA) pose a high risk of transmission of respiratory tract infections (RTIs). Hand hygiene (HH) is a fundamental infection control measure, but its preventive role against RTIs during mass gatherings (MGs) lacks focused research. Therefore, this PhD thesis aimed to assess knowledge, perceptions, and practices regarding HH and its role in preventing viral RTIs among attendees of religious MGs in KSA during the COVID-19 pandemic while also exploring the burden and patterns of RTIs among pilgrims. Five observational studies and a pilot randomised control trial (RCT) were conducted between 2019 and 2021 among domestic Hajj and Umrah pilgrims in Makkah and visitors to the Prophet's Mosque in Al Madinah, in addition to a systematised review study. The systematised review identified a high risk of RTIs during Hajj, regardless of pilgrims’ nationality. However, my studies found an overall low prevalence of RTIs among pilgrims during the pandemic, with even lower rates of possible COVID-19. Participants demonstrated moderate HH knowledge, with no apparent improvement during the pandemic. Yet, the majority of participants believed in HH methods' effectiveness against viruses like COVID-19. Compliance with HH practices was generally good, with handwashing with soap being the preferred method. However, no statistically significant difference in HH compliance rate or RTI rates was found between the intervention and control groups in our trial during the pandemic, suggesting inconclusive evidence of HH's protective role during Umrah. The trial successfully demonstrated the feasibility of a future large trial within the Umrah setting. Ongoing efforts to improve HH knowledge and compliance among pilgrims are essential, along with further research to refine preventive measures in MG contexts. These results have significant implications for global public health policy, not only in KSA but also in similar MG settings globally.218enHajjHand hygieneMass gatheringRespiratory tract infectionsUmrahThesis