Ongoing mumps outbreak in Israel, January to August 2017.

In Israel, 262 mumps cases were registered between 1 January and 28 August 2017 despite a vaccine coverage of >/=96%. The majority (56.5%) of cases were adolescents and young adults between 10 and 24 years of age. Nearly twice as many cases were reported in males than in females. Sequence information identified genotype G and suggested specific transmission chains in different religious communities, with the Muslim population in Jerusalem being most severely affected.