Mumps is a vaccine preventable disease caused by mumps virus (family: Paramyxoviridae, genus: Rubulavirus) with a subclinical course in up to one third of all cases. Common manifestations in all patients include parotitis and respiratory symptoms and orchitis in postpubertal males. Laboratory diagnosis is usually done by detecting specific IgM antibodies or mumps virus RNA. Based on 316 nucleotides covering the small hydrophobic (SH) gene region, 12 different genotypes of mumps virus have been proposed with genotypes C, F, G and H predominating in Asia. In Lao People’s Democratic Republic (PDR), mumps is not a notifiable disease and mumps vaccine is currently not included in the routine childhood immunization schedule. While no data exist for previous years, a total of 54 cases were reported to WHO in 2011. Studies investigating the seroprevalence of mumps-specific IgG antibodies are lacking for Lao PDR and thus the public health burden of mumps in this country is currently unknown.
The Lao Lux laboratory, in collaboration with NCLE, carries out passive surveillance of mumps outbreaks within Lao PDR. Seroprevalence data are also determined on a country-wide scale. These investigations allow assessment of the burden of disease and transmission routes of the mumps virus within Lao PDR.
These studies are the basis for a first assessment of the public health benefit including mumps in the EPI programme.