Introduction:: Neglected infectious diseases like mumps may be opportunistic in controlled areas with low vaccine coverage, particularly in developed and emerging countries.
Methods:: A retrospective analysis of mumps-related data from 2001 to 2016 for São Paulo State, Brazil was conducted.
Results:: From 2014 to 2015, there was an increase of 82% in reported mumps cases in São Paulo, with prevalence of n=49 and 297, respectively in young adults aged 15-29 years.
Conclusions:: A booster-shot campaign on MMR vaccination is recommended to prevent the spread of mumps in unvaccinated children and recipients of only the first dose.