Consequences of a University Mumps Outbreak in the Context of a Larger State Outbreak

During February–June 2017, University of Washington (UW) experienced a mumps outbreak with 42 cases. All patients had received ≥2 documented doses of measles, mumps, and rubella (MMR) vaccine consistent with recommended vaccination schedules; and 2-dose MMR coverage among all UW students was ˃99%. Although the UW outbreak occurred amid Washington State’s largest mumps outbreak in 40 years, accounting for approximately 16% of all U.S. mumps cases during the time period, the two outbreaks were unrelated (different virus lineages in specimens tested).

In a university-wide effort encompassing many of the non-academic departments, UW collaborated with state and local public health departments (PHD) to rapidly implement outbreak investigation and response activities including recommending an additional dose of MMR vaccine to all UW students. Preliminary results indicate that the total costs to UW and PHD in responding to the 2017 UW Mumps Outbreak were approximately $287,000 ($6,692 per case), with more than 2,600 logged personnel hours. UW spent more than PHD, with $160,000 ($3,825 per case) and nearly 1,500 hours responding to the outbreak, accounting for over half of the total cost. Overall, labor was the largest driver of costs for the outbreak response; UW labor costs related to campus response planning and coordination dominated the total economic burden from a public health and university perspective. The Environmental Health and Safety Department and the Hall Health Center incurred ≈85% of UW’s total costs, although neither department had a budget for emergency outbreak response activities.

UW spent noticeably more hours than PHD (1) planning how to respond to the outbreak, (2) preparing for the vaccination clinics, and (3) conducting a massive outreach and education campaign. The majority of PHD’s labor was allocated to laboratory testing of ill persons, case/contact investigation, and vaccination. During any infectious disease outbreak, the resources needed to identify cases and contacts can strain limited state and local public health resources. In the case of the UW outbreak, PHD resource constraints were exacerbated by the larger, statewide outbreak.

Mumps outbreaks in highly 2-dose vaccinated populations are increasing across the United States, triggering discussion on prevention versus control strategies subject to the competing demands on public health agencies and affected institutions. In October of 2017, the Advisory Committee on Immunization Practices recommended a third dose of MMR vaccine for individual protection for persons at increased risk during outbreaks. Questions that remain to be answered include (1) what were the specific economic consequences of this adverse health event from a societal perspective? (2) what consequences could have been avoided through different degrees of intervention and at what cost? (3) what collaborations could have reduced costs? Further research will be presented on interventions that might have prevented the outbreak (such as adding an additional dose to the current 2-dose MMR vaccination regimen) or controlled the outbreak (such as variations of existing control measures or business-as-usual). In an endogenous risk framework, we evaluate the economic implications of these interventions in the context of the UW outbreak to determine the optimal prevention and control strategy.