title: Laboratory-based investigation of suspected mumps cases submitted to the German National Reference Centre for Measles, Mumps, and Rubella, 2008 to 2013.
abstract: From 2008 to 2013, sample sets from 534 patients displaying clinical symptoms of mumps were submitted to the German Reference Centre for Measles, Mumps and Rubella. Mumps virus infection was confirmed in 216 cases (40%) by PCR and/or serology. Confirmed cases were more frequently seen in male than in female patients (128 vs. 81); the age group predominantly affected was 15 to 29 years old (65%, median age: 26.4 years). The majority of the confirmed cases had a remote history of vaccination with one or two doses of a mumps-containing vaccine (69%). Our results indicate that mumps virus caused two outbreaks in Bavaria in 2008 and 2010/2011 and a third one in Lower Saxony in 2011. Mumps virus genotype G was preponderantly detected from 2008 to 2013. For 107 of the 216 patients with a confirmed mumps infection, we correlated the results from PCR and serology. PCR detected cases during the first week after onset of symptoms (74% positive results). PCR worked best with throat swabs and oral fluids (61% and 60% positive results, respectively). IgM was more reliable with a longer time after onset of symptoms (67%), but indirect IgM serology was of insufficient sensitivity for vaccinated mumps cases (30%); the IgM μ-capture assay detected more cases in this group. Mumps virus is able to initiate an infection in vaccinated patients (secondary vaccine failure, SVF) although it is unclear to what extent. Since SVF does occur in highly vaccinated populations and IgM will not increase to detectable levels in all SVF patients, we strongly recommend using PCR plus serology tests to avoid false-negative diagnoses in vaccinated individuals with clinical signs of mumps.
authors.affiliation: Robert Koch-Institute, National Reference Centre Measles, Mumps, Rubella, Seestr. 10, D-13353 Berlin, Germany. Electronic address: mankertza@rki.de.
authors.forename: Annette
authors.initials: A
authors.lastname: Mankertz
authors.affiliation: Vördener Str 38, 49401 Damme, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Beutel
authors.affiliation: Marienstraße 13, 49377 Vechta, Germany.
authors.forename: Franz-Josef
authors.initials: FJ
authors.lastname: Schmidt
authors.affiliation: Klinikum Ingolstadt, Department of Clinical Infectiology and Infection Control, Ingolstadt, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Borgmann
authors.affiliation: Institute of Clinical Microbiology and Hygiene, Regensburg University Medical Center, Regensburg, Germany.
authors.forename: Jürgen J
authors.initials: JJ
authors.lastname: Wenzel
authors.affiliation: Public Health Department Landshut, Landshut, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Ziegler
authors.affiliation: Institute of Virology and Immunobiology, University Würzburg, Würzburg, Germany.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Weißbrich
authors.affiliation: Robert Koch-Institute, National Reference Centre Measles, Mumps, Rubella, Seestr. 10, D-13353 Berlin, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Santibanez
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D005188:False Negative Reactions; D005260:Female; D005838:Genotype; D005858:Germany / Q000453:epidemiology; D006801:Humans; D008297:Male; D009107:Mumps / Q000175:diagnosis* / Q000453:epidemiology*; D009109:Mumps virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*; D017678:Sex Distribution; D055815:Young Adult
keywords: German Reference Centre; Laboratory confirmation test; Molecular surveillance; Mumps virus; Vaccination; Vaccination failure