Parotitis epidemica – colloquially called mumps or goat mumps – (synonyms: parotitis epidemica (mumps); salivitis epidemica; ICD-10 B26.-: Mumps) is an acute (sudden onset) and generalized viral infection. The responsible paramyxovirus (RNA virus) belongs to the genus Rubulavirus, from the family of paramyxoviruses.
Humans currently represent the only relevant pathogen reservoir.
Occurrence: Infection occurs worldwide.
To quantify the contagiousness mathematically, the so-called contagiousness index (synonyms: contagiousness index; infection index) was introduced. It indicates the probability with which a non-immune person becomes infected after contact with a pathogen. The contagiousness index for parotitis epidemica is 0.40, which means that 40 out of 100 unvaccinated persons become infected after contact with a mumps-infected person.Manifestation index: Approximately 50% of mumps-infected persons become recognizably ill with mumps.
Mumps occurs in epidemics, that is, highly clustered locally and temporally.
Seasonal accumulation of the disease: Mumps occurs more frequently in the cold season.
Transmission of the pathogen (route of infection) occurs primarily via droplets that are produced when coughing and sneezing and are absorbed by the other person via the mucous membranes of the nose, mouth and possibly the eye (droplet infection) or aerogenically (through droplet nuclei containing the pathogen (aerosols) in the exhaled air). Furthermore, infection can occur via smear infection (e.g. direct saliva contact).
Human-to-human transmission: Yes.
The incubation period (time from infection to onset of disease) is usually 16-18 days (12-25 days is possible).
Sex ratio: Boys are affected twice as often as girls.
Peak incidence: the disease occurs predominantly between the ages of 4 and 15 years, but also in adulthood – then with more frequent complications.
Seroprevalence (number (in percent) of positive serological parameter tested): In women of childbearing age, mumps virus IgG (immunoglobulin G) antibody prevalence is 60-70%.
The incidence (frequency of new cases) is approximately 0.7 cases per 100,000 population per year.
Duration of infectivity (contagiousness) is from day 7 before parotid swelling (swelling of salivary glands) until complete resolution (approximately 9 days thereafter); it is greatest 2 days before to 4 days after onset of disease. Clinically inapparent (“non-appearing”) infections are also contagious.
The disease leaves lifelong immunity. However, reinfection is possible (due to incomplete cross-neutralization of the different mumps virus genotypes; decreasing protection).
Course and prognosis: In about one third of those infected, the infection is mild or asymptomatic (without noticeable symptoms). As a rule, the prognosis is good. Rarely, complications such as myocarditis (inflammation of the heart muscle) or encephalitis (inflammation of the brain) occur. An increased rate of miscarriage and premature birth after mumps infection is not to be assumed.
Lethality (mortality related to the total number of people infected with the disease): 1 ‰ of those infected.
Vaccination: a protective vaccination against mumps is available.
In Germany, direct or indirect detection of the pathogen is reportable under the Infection Protection Act (IfSG) if the evidence indicates acute infection.
