Lessons learned from an under-reported mumps epidemic among Rohingya refugees in Cox's Bazar District, Bangladesh.

BACKGROUND In 2018, a large mumps epidemic coincided with an outbreak of diphtheria in refugee camps established in Bangladesh for the Rohingya people. These refugees did not receive a mumps-containing vaccine. METHODS Cases of mumps were reported to the WHO's Early Warning, Alert and Response System (EWARS) during the Rohingya refugee crisis. The authors present amalgamated epidemiological data of a major, previously under-reported, mumps epidemic. RESULTS In total, 19 215 mumps cases across a total of 218 facilities were reported to EWARS during 2018. The attack rate was 2.1% of the whole population. Of these cases, 7687 (40%) were in children aged <5 y. Mumps was more commonly seen among males than females. CONCLUSION Detailed reporting of outbreaks of all vaccine-preventable diseases is essential to ensure appropriate vaccination decisions can be made in future humanitarian crises.