Health-related research publications on religious mass gatherings of Muslims: a bibliometric analysis (1980-2020).

Research on mass gatherings, specifically the Hajj, is emerging. Researchers from the Saudi Arabia dominated the field. Research collaboration between scholars in Saudi Arabia and scholars in low- and middle-income countries is needed and must be encouraged since these countries have weaker health systems to screen, monitor, and control the spread of infectious diseases because of the Hajj season.