Related Experiment Videos
Mumps outbreak in vaccinated children in Gipuzkoa (Basque Country), Spain
1Servicio de Microbiologia, Hospital Donostia, Paseo Dr. Beguiristain s/n, 20014 San Sebastián, Spain.
Insights
A mumps outbreak occurred in vaccinated children despite a measles-mumps-rubella (MMR) revaccination campaign. Genotyping revealed wild-type mumps virus strains, distinct from those used in the MMR vaccines.
Area of Science:
- Virology
- Epidemiology
- Immunology
Background:
- Mumps outbreaks can occur in vaccinated populations.
- The measles-mumps-rubella (MMR) vaccine is crucial for mumps prevention.
- Understanding vaccine strain effectiveness against circulating wild-type mumps virus is important.
Purpose of the Study:
- To investigate a mumps outbreak in vaccinated children.
- To identify the genotype of the circulating mumps virus strains.
- To compare outbreak strains with vaccine strains.
Main Methods:
- Case confirmation through viral culture, RNA detection, and IgM testing.
- Analysis of mumps virus strains from clinical cases.
- Sequencing of the small hydrophobic (SH) gene for genotyping.
- Comparison of identified genotypes with vaccine strains.
Main Results:
- A mumps outbreak occurred in 3-4 year olds, with an attack rate of 47.9%.
- Eighty-eight percent of affected children received the Rubini MMR vaccine strain.
- The outbreak was caused by an H genotype wild-type mumps virus, different from the D genotype causing sporadic cases.
- Sequencing identified heterologous genotypes compared to vaccine strains.
Conclusions:
- The study identified a mumps outbreak caused by a wild-type H genotype strain in a vaccinated population.
- The findings suggest that the vaccine strains (Rubini and Jeryl-Lynn) may not have provided complete protection against this circulating genotype.
- Further research into vaccine effectiveness against diverse mumps virus genotypes is warranted.
Abstract:
A mumps outbreak occurred in a group of vaccinated children aged 3-4 years in San Sebastián (Gipuzkoa, Basque Country, Spain) in 2000 during the same period as a revaccination campaign against measles-mumps-rubella (MMR) was performed. The clinical cases were confirmed by viral culture, detection of viral RNA and/or specific IgM. Eighty-eight percent of the children had been vaccinated with the Rubini strain and the remainder with the Jeryl-Lynn strain. The attack rate was 47.9% (35 cases in 73 school-attending children of this age). The outbreak was caused by an H genotype strain of mumps virus which was circulating at the same time as a D genotype strain that caused sporadic cases. By sequencing the small hydrophobic (SH) gene, the strains of the clinical cases were identified as wild-type mumps virus with heterologous genotypes in comparison to the vaccine strains used in our area.