2016-2017 Influenza Update for Health Care Providers: Parotitis and Influenza

During the 2014-2015 influenza season in the United States, several hundred cases of confirmed influenza infection with parotitis were reported to CDC. Previous to 2014, only about a dozen such cases had ever been reported in the scientific literature. Parotitis after influenza infection appears to occur in people of all ages, but is most common in school-aged children and in males. Parotitis appears to occur more often after infection with influenza A (H3N2) viruses. Among patients who had parotitis with influenza during the 2014-2015 influenza season, more than 80% had one respiratory symptom or more (cough, sore throat, or runny nose); most had mild illness. There is no evidence of increased severity of illness and no deaths have been reported in patients with influenza-associated parotitis.

CDC has received a report of influenza infection with parotitis this year; this illness was associated with an influenza A (H3N2) virus infection. While influenza activity is still low at this time, influenza A (H3N2) viruses were most common in the United States from May through mid-September. If influenza A (H3N2) viruses continue to predominate, more cases of influenza with parotitis may occur this season.

CDC recommends that, during the 2016-2017 influenza season, clinicians evaluating a patient with acute parotitis that is not associated with a laboratory-confirmed mumps outbreak should include influenza in the differential diagnosis and consider testing the patient for influenza viruses even in the absence of respiratory symptoms.

The best way to test for mumps virus infection is with a buccal, or oral, swab and blood test (see Mumps Specimen Collection, Storage, and Shipment). The best way to test for influenza is with a nasopharyngeal or oropharyngeal swab (see Influenza Specimen Collection [103 KB, 1 page] information). Note that a buccal swab is not an approved specimen for influenza diagnostic testing.

Influenza antiviral treatment is not recommended solely because a patient has influenza-associated parotitis, but may be warranted for other reasons. CDC influenza antiviral treatment guidelines state that prompt influenza antiviral treatment is recommended for any patient with confirmed or suspected influenza who is 1) hospitalized, 2) has severe, or progressive, illness, or 3) is at high risk of developing influenza-associated complications. Because early antiviral treatment can shorten the duration of influenza symptoms, antiviral treatment also can be considered for any previously healthy, symptomatic outpatient with confirmed or suspected influenza on the basis of clinical judgment, ideally within 48 hours of illness onset.

Positive laboratory results should be reported to state and local health departments according to local reporting requirements. In all states, mumps positive results are reportable. In some states, influenza positive results are reportable. CDC will continue to monitor this situation and provide updates as more information becomes available. More information about influenza and parotitis is available at Influenza & Parotitis: Question & Answers for Health Care Providers.