Epidemic of Mumps among Vaccinated Persons, the Netherlands, 2009–2012

• DOI: 10.3201/eid2004.131681
• Publication Date: 2014-02-27T14:47:31Z
• Authors: Jussi Sane; Sigrid Gouma; Marion Koopmans; Hester de Melker; Corien Swaan; Rob van Binnendijk; Susan Hahné
• Keywords: MMR vaccine; Measles-Mumps-Rubella Vaccine; Mumps vaccine

To analyze the epidemiology of a nationwide mumps epidemic in Netherlands, we reviewed 1,557 notified cases persons who had disease onset during September 1, 2009-August 31, 2012. Seasonality peaked spring and autumn. Most case-patients were males (59%), 18-25 years age (67.9%), vaccinated twice with measles-mumps-rubella vaccine (67.7%). Nearly half (46.6%) occurred university students or student contacts. Receipt 2 doses reduced risk for orchitis, most frequently reported complication (vaccine effectiveness [VE] 74%, 95% CI 57%-85%); complications overall (VE 76%, 61%-86%); hospitalization 82%, 53%-93%). Over time, distribution changed, proportionally more from nonuniversity cities (p<0.001). Changes geographic over time may reflect increased immunity among resulting intense exposure to circulating virus.