Four cases of mumps were reported to MDH during 2004; a total of 23 mumps cases were reported between 20002004. Three of the case-patients were white, non-Hispanic males, ages 22, 44 and 50 years. The fourth case-patient was a 37-year-old white, non-Hispanic female. All four cases had an unknown history of vaccination for mumps. Between 2002 and 2004, eight of the 10 cases reported have occurred in adults, highlighting the need to assess the mumps immunization status of adults.
No source case was identified for two of the cases (ages 22 and 50 years). The 44-year-old reported a history of domestic travel that included meeting with persons from numerous other states and Canada. He and the female case-patient were epidemiologically linked. Transmission of mumps had not previously been identified in Minnesota since 1999.
All four cases were laboratory confirmed by positive IgM serology. Convalescent serum results were unavailable; therefore, a rise in serum IgG was not verified. Specimens for viral culture were not collected from any of the cases. Although IgG serologic tests and viral culture were not performed for the two epidemiologically linked cases, the clinical presentation (including orchitis in the male), negative laboratory test results for common differential diagnoses (e.g., mononucleosis and streptococcal infection), and the relative symptom onset dates supported the diagnosis of mumps. Neither case developed additional complications nor was hospitalized. Close contacts were notified of their exposure; no subsequent transmission was identified.
Both IgM and IgG serologic testing should be performed on suspect mumps cases, as false-positive indirect immunofluorescent antibody (IFA) tests for mumps IgM have been reported. Mumps can also be confirmed by viral culture of throat washings, urine, or spinal fluid specimens. Specimens for viral culture should be collected during the first 5 days of illness.
Go to full issue: DCN, July/August 2005: Volume 33, Number 4