Mumps, 2019

In 2019, 11 mumps cases were reported. Nine were classified as confirmed (tested positive by PCR), and 2 as probable (tested positive by IgM serology or were linked to another case or outbreak). Two were genotyped as K, a common genotype circulating in mainland southeast Asia. The remaining confirmed cases were genotyped as G, which is the dominant genotype circulating in the United States since 2006. Eight cases had a documented history of receiving at least 1 dose of mumps-containing vaccine, 1 was unvaccinated, and 2 reported unknown vaccination status. No case reported a previous history of mumps disease.

Seven cases occurred in a county jail housing U.S. Immigration and Customs Enforcement detainees linked to larger national outbreak involving 898 cases in 19 states. Two cases were acquired in Minnesota and were not linked to outbreaks occurring elsewhere, 1 acquired mumps from domestic travel, and 1 from international travel. The median age of cases was 27 years (range 3 to 36 years). Ten cases occurred in persons 18-49 years, and 1 was <18 years of age. Ten experienced parotitis, and 1 reported orchitis.

Mumps surveillance is complicated by nonspecific clinical presentation in nearly half of cases, asymptomatic infections in an estimated 30% of cases, and suboptimal sensitivity and specificity of serologic testing. A number of viruses can cause sporadic parotitis including parainfluenza virus types 1 and 3, influenza A virus, human herpes virus 6, enterovirus, Epstein- Barr virus, lymphocytic choriomeningitis virus, bocavirus, and human immunodeficiency virus. Acute bacterial parotitis may present with unilateral swelling. Noninfectious causes include drugs, tumors, and immunologic diseases.

• Find up to date information at>> Mumps
• Full issue>> Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2019