Sciensano is responsible for the surveillance of mumps in Belgium and coordinates different surveillance networks. Sciensano is also the National Reference Centre (NRC) for mumps, measles and rubella. We focus on research of vaccine efficacy, investigate outbreaks and measure the seroprevalence in the population.
Mumps is a contagious vaccine preventable viral disease, affecting the upper respiratory tract en salivary glands. The disease is mostly mild, but complications may occur. Since 1985, children in Belgium are systematically vaccinated with a combined vaccine against mumps, measles and rubella.
What is mumps?
Mumps is a viral disease affecting humans only. It is caused by the mumps virus, which belongs to the Paramyxoviridae family. The virus is transmitted through air droplets or direct contact with the infected subject.
Mumps is known as a childhood disease, although all age groups can be affected. The incubation time is about 12 to 25 days. First symptoms include fever and general illness. In about two thirds of all mumps cases, the infection leads to a typical swelling of the cheeks, due to infection of the salivary glands (parotitis). The disease typically lasts about 2 weeks. In some cases, complications can occur, such as inflammation of the testicles (orchitis), ovaries (oophoritis), the brain (encephalitis) or the brain membranes (meningitis). Up to 30% of mumps cases are asymptomatic. In about 1% more severe complications occur. Death rarely occurs. No lethal case has been reported in Belgium during the outbreaks that occurred in the recent years.
Mumps is mostly diagnosed clinically, as the swelling of the cheeks gives an indication of mumps virus infection. Additionally, laboratory confirmation is done by detection of the virus in nasal or salivary swabs, or by detecting anti-mumps virus antibodies in the serum.
Since 1985, children in Belgium are systematically vaccinated against the mumps virus with the trivalent measles-mumps-rubella (MMR) vaccine, as recommended by the Belgian Superior Health Council. The vaccine is administered at the age of 12 months and a booster dose is given at 10-12 years. More information on the vaccination and the vaccination schedule is only available in Dutch and French.
Consequently to this vaccination schedule, mumps now mainly affects older age groups (18-24 year olds), as protection after vaccination might decrease in time. In 2011-2013, Belgium faced a major mumps outbreak among university students, of whom most had been vaccinated at least once with the MMR vaccine.
In Europe, vaccines may only be marketed if an Official European Medicines Control Laboratory (OMCL) has assessed and confirmed their quality by laboratory testing and critical data protocol review. It is one of the roles of the service Quality of Vaccines and Blood Products within Sciensano.
Children who have not been vaccinated, young adults who have been vaccinated only once or adults born before 1985 without being infected and individuals vaccinated a longer time ago, face a higher risk of contracting mumps. Complications are more common in adults.
No curative treatment is available for mumps. Current therapy is solely based on symptomatic treatment.