Mumps, 2015

Six mumps cases were reported in 2015. All six were residents of the metropolitan area. One was classified as confirmed (tested positive by PCR) and 5 as probable (tested positive by IgM serology or were epidemiologically linked to another case or outbreak).

The confirmed case had recently returned from the Caribbean. Lab testing revealed that her genotype matched a common wild-type mumps genotype circulating in that region. One of the 5 probable cases was IgM negative but was epidemiologically linked to an ongoing outbreak at an Iowa university. The remaining 4 probable cases were positive by IgM serology and were not epidemiologically linked to each other or to a source case. Mumps surveillance is complicated by nonspecific clinical presentation in nearly half of cases, asymptomatic infections in an estimated 20% of cases, and suboptimal sensitivity and specificity of serologic testing.

Cases ranged in age from 15 to 73 years. One case occurred in a person <18 years of age; 2 cases occurred in persons 19 through 33 years of age; 1 case was 42 years old; and 2 cases occurred in persons ≥50 years. Two cases reported a history of receiving at least 1 dose of mumps-containing vaccine but had no documentation of those doses; one case reported never having received any doses of mumps-containing vaccine, and 3 cases (including 2 born prior to 1957) had unknown vaccination status.

• For up to date information see>> Mumps
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2015