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Mumps in a Highly Vaccinated Marshallese Community

Lancet Infect Dis; ePub 2019 Jan 8; Fields, et al

In a highly vaccinated Marshallese community in Arkansas, a large-scale outbreak of mumps primarily affecting a marginalized community with intense household crowding may be related to mumps vaccine effectiveness and potential waning immunity, a new study suggests. From August 5, 2016, to August 5, 2017, the Arkansas Department of Health received notification of >4,000 suspected mumps cases in the second largest outbreak in the US in the past 30 years. The outbreak report included the following:

  • 2,954 cases of mumps related to the outbreak were identified during the outbreak period: 1,665 (56%) were laboratory confirmed, 1,676 (57%) were in children aged 5-17 years, and 1,692 (57%) were in Marshallese people.
  • Among the school-aged cases, 92% had previously received at least 2 doses of a vaccine containing the mumps virus.
  • Although 19 cases of orchitis were reported, severe complications were not identified.
  • Viral samples were characterized as genotype G.


Fields VS, Safi H, Waters C, et al. Mumps in a highly vaccinated Marshallese community in Arkansas, USA: An outbreak report. [Published online ahead of print January 8, 2019]. Lancet Infect Dis. doi:10.1016/S1473-3099(18)30607-8.