title: Mumps virus diagnosis and genotyping using a novel single RT-PCR.
abstract: BACKGROUND
  IgM detection is considered as the gold standard for mumps diagnosis. Currently, most cases in developed countries occur in highly vaccinated populations due to secondary vaccine failure. In these patients, pre-existing vaccine-induced antibodies are not able to neutralise the virus, but prevent the typical primary response, so that specific IgM is not always elicited. Consequently, acute infection has to be demonstrated by direct detection of the virus by viral isolation or genomic amplification. RT-PCR allows a diagnosis with the maximum sensitivity to be made and also forms the basis for genotype characterisation by sequencing the SH gene, according to WHO recommendations. However, none of the RT-PCR techniques properly evaluated for the diagnosis of acute mumps infection yields an amplification fragment useful for genotyping, and none of the amplification techniques described for genotyping has proved to be sensitive enough for diagnosis.
  
  
  OBJECTIVE
  Development of a RT-PCR for the mumps virus diagnosis and genotyping, properly evaluated in comparison with serological gold-standard technique.
  
  
  METHODS
  195 suspected mumps cases and six wild type MuV genotypes were studied.
  
  
  RESULTS
  Our method was able to detect 0.001 TCID(50) of mumps virus. Fifty-eight of these showed positive results, of which 54 (93.3%) showed mumps RNA in saliva, while only 20 (34.5%) had mumps IgM in serum. Genotypes G1, G2, H1, H2, D1 and C were identified in positive samples.
  
  
  CONCLUSIONS
  The technique described could be a very useful tool for mumps surveillance, management and control.
authors.affiliation: Network of Biomedical Investigation Centres (CIBER) in Epidemiology and Public Health (CIBERESP), Barcelona, Spain. eroyuela@isciii.es
authors.forename: Enrique
authors.initials: E
authors.lastname: Royuela
authors.forename: Ana
authors.initials: A
authors.lastname: Castellanos
authors.forename: Carmen
authors.initials: C
authors.lastname: Sánchez-Herrero
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Sanz
authors.forename: Fernando
authors.initials: F
authors.lastname: De Ory
authors.forename: J E
authors.initials: JE
authors.lastname: Echevarria
mesh_terms: D000914:Antibodies, Viral / Q000097:blood; D005838:Genotype; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D009107:Mumps / Q000175:diagnosis*; D009109:Mumps virus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012463:Saliva / Q000821:virology; D012680:Sensitivity and Specificity; D014773:Virology / Q000379:methods*
chemical_list: D000914:Antibodies, Viral; D007075:Immunoglobulin M