Laboratory Studies
Mumps has traditionally been considered a clinical diagnosis. However, data from a 2007 outbreak found that only 298 of 2082 cases (14%) of clinically diagnosed mumps were laboratory confirmed. [22] Laboratory evaluation is usually undertaken in the emergency department to look for other causes of a patient's symptoms or to evaluate for complications or comorbidity. Mumps-specific tests can generally be performed on an outpatient basis.
Mumps virus can be isolated from nasopharyngeal swabs, urine, blood, and fluid from buccal cavity typically from 7 days before up until 9 days after the onset of parotitis.
Mumps infection can be confirmed by demonstrating the following:
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Significant rise in mumps-specific immunoglobulin G (IgG) antibody between acute and convalescent titers
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Positive mumps immunoglobulin M (IgM) result
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Isolation of mumps virus or nucleic acid via polymerase chain reaction (PCR) from an oral or buccal swab
Leukocytosis or leukopenia may be present with lymphocyte predominance.
Serum amylase levels may be elevated.
CNS infections usually exhibit a lymphocytic pleocytosis. A viral culture of CSF (within first 3 days of clinical symptoms), urine (within first 2 weeks of symptoms), or saliva (starting on day 2 of symptoms and for one week after) can also be used to make the diagnosis. [23]
Imaging Studies
No specific imaging studies are diagnostic.
Imaging studies may be needed as a further workup with certain complications of mumps.
Testicular ultrasonography may be performed when acute orchitis is suspected, with specific indication to rule out torsion.
Procedures
Consider lumbar puncture if there is a concern for possible meningitis.
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Child with mumps.
