Clinician Alert: Mumps in Multnomah County

September 18, 2019

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Since the beginning of August, Multnomah County has identified 5 cases of mumps. Three are in school-aged children who are fully vaccinated; vaccination status has not been verified for the other two cases. So far, all appear to have links to the Federated States of Micronesia, which includes the Pacific Island states of Yap, Chuuk, Pohnpei, and Kosrae.

We are asking providers to identify additional cases to help track further spread.

If you see a patient with salivary gland swelling:

  • Include mumps in your differential diagnosis, even if the patient is fully vaccinated.

  • Consider collecting a respiratory panel to rule out other respiratory illnesses

  • Minimize exposure to other patients and use droplet and standard precautions.

  • In patients with a reported history of MMR vaccination, the preferred test for diagnosis is mumps PCR.

    • If 3 days or less since onset of symptoms, obtain a buccal swab for testing.

    • If more than 3 days since onset, obtain both a buccal swab and a urine sample for PCR testing.

      • Buccal: Dacron swabs in viral transport medium (VTM)

      • Urine: Clean catch urine in sterile cup

      • Refrigerate specimens until ready for transport to appropriate lab

  • In unvaccinated patients, performing both mumps IgM serology and mumps PCR can increase the chances of detection.

  • Testing through the public health laboratory is approved on a case-by-case basis through the county public health department where the patient lives.

  • Commercial laboratories perform mumps PCR testing but results can take several days.

  • Any patient who is tested for mumps should be asked to isolate at home for 5 days after the onset of parotitis.

  • For suspected mumps cases, get good contact information and report to the public health department of the county where the patient lives.

More about mumps

Most persons with mumps present with salivary gland swelling, usually parotitis. Prodromal symptoms may include low-grade fever, myalgia, anorexia, malaise, and headache. Some persons may be asymptomatic or have only nonspecific or respiratory symptoms. 

Complications are infrequent but include orchitis, oophoritis, encephalitis and meningitis. Mumps is spread through close contact with respiratory secretions, and infected persons are most infectious 2 days before and 5 days after onset of parotitis. The incubation period of mumps is 12–25 days (average 16-18 days).


CDC information on mumps:

CDC information on mumps outbreaks in the U.S.:

Tri-County Public Health Offices

Clackamas County: 503-655-8411

Multnomah County: 503-988-3406

Washington County: 503-846-3594