Incubation period

The time between infection and the appearance of the first symptoms (incubation period) is between 12 and 25 days for mumps. Almost half of those infected show no symptoms at all and only signs of a flu-like infection. Mumps is already contagious one week before the first symptoms appear and up to nine days after the swelling of the salivary glands has subsided. It is important to know that mumps is contagious even without symptoms.

Diagnosis

The diagnosis can usually be made by the presence of a typical clinical picture (clinical findings): The mumps-characteristic symptom of the parotid gland swelling speaks decisively for the diagnosis of this infectious disease. Other diagnostic measures include the determination of antibodies against the mumps virus in the blood: IgM class antibodies indicate disease from mumps, while IgG class antibodies prove the patient’s immunity to the virus. Only rarely is direct detection of the virus carried out by means of a throat swab or from saliva (S. immune system).

The blood amylase level is characteristically elevated; this enzyme is found in saliva and pancreatic secretion. Since this value is also elevated in the case of inflammation of the pancreas, the concentration of the enzymes (= biocatalysts of the body) elastase 1 and lipase in the blood is determined by further laboratory tests. If the values of these two enzymes, which are specific for the pancreas, are within the normal range and if an ultrasound examination of the pancreas is inconspicuous, an inflammatory involvement of the pancreas is ruled out.

Differential DiagnosisExclusion Diseases

Salivary stones are to be distinguished from mumps, which prevent the outflow of saliva from the salivary glands of the head and therefore an inflammatory process with organ swelling occurs in the duct system of the glands. The symptoms of lymphadenitis colli are similar to those of mumps: there is a swelling of the cervical lymph nodes, but this swelling is not painful like in mumps and does not cause the earlobes to protrude.