Measles in conflict-affected northern Syria: results from an ongoing outbreak surveillance program.

The 2017 and 2018 measles epidemics were the largest since Syria eliminated the disease in 1999. The regions most affected by these outbreaks were areas of intense conflict and displacement between 2014 and 2018, including districts in Ar-Raqqa, Deir-Ez-Zor, and Idlib. The spread of measles in northern Syria serves as an indicator of low immunization coverage and limited access to care and highlights the Syrian peoples' vulnerability to infectious diseases and vaccine preventable diseases in the setting of the current conflict.