Tuberculosis and mass gatherings—opportunities for defining burden, transmission risk, and the optimal surveillance, prevention, and control measures at the annual Hajj pilgrimage

Highlights • The ease of international travel is responsible for the spread of tuberculosis (TB) across the world. • Accurate data on the actual burden of TB and the transmission risk associated with mass gatherings are scarce and unreliable. • Every year an estimated 10 million pilgrims from 184 high TB endemic countries travel to Saudi Arabia to perform the Hajj and Umrah pilgrimages. • The Hajj pilgrimage provides unique opportunities to conduct high quality priority research studies on TB. • Research opportunities for defining the TB burden, transmission risk, and the optimal surveillance, prevention, and control measures at the annual Hajj pilgrimage are discussed.