Genetic diversity of mumps virus in oral fluid specimens: Application to mumps epidemiological study

Three hundred nine mumps virus (MuV) strains detected in the United Kingdom during 1995-2002 were characterized by partial sequencing of the small hydrophobic gene and were shown to belong to at least 6 different genotypes. A strain representing a new genotype was isolated from a seminal fluid specimen. Identical strains belonging to genotypes G and C were found to circulate for up to 3 years. One genotype H strain reappeared after an absence of 4 years. Distinct lineages (G1-G7) within genotype G were recognizable in the present study, and this level of characterization proved to be very useful for tracking MuV importations and subsequent transmission. We propose, here, a preliminary standardization of international nomenclature for genetic characterization of MuV strains, to facilitate future molecular epidemiological studies of mumps. Oral fluid (OF) specimens (n = 1441) were used to detect both anti-MuV IgM and MuV genome, and the results indicate that OF specimens can be used successfully for diagnosis and have the potential to play a valuable role in diagnosis and surveillance of mumps.