Understanding the Spread of Mumps in U.S. Immigration and Customs Enforcement Facilities: a Metapopulation Analysis

Abstract

This study addresses an ongoing mumps outbreak affecting dozens of U.S. immigration detention facilities and the conditions and outbreak response measures that impacted its spread throughout Texas, where the outbreak began; by developing an epidemiological metapopulation model to assess how various parameters impact the scope of the outbreak, I form recommendations to prevent and minimize potential future mumps outbreaks. Immigration detention efforts have reached an unparalleled high over the past decade, with more than 40,000 individuals held in detention daily during 2018. Conditions within detention facilities are highly conducive to infectious disease spread and while mumps does not cause severe physical symptoms, outbreak response is costly and utilizes valuable public health resources. In this study, I build a metapopulation model to fit mumps spread throughout eight Texas detention facilities, then examine how daily detainee transfers, case detection, and vaccination efforts affect total and within-facility spread over the first eight weeks of the outbreak. By examining the impact of individual and combined measures on spread, I find that administering a third dose of MMR vaccine to all existing and incoming detainees causes the greatest reduction in total mumps cases after eight weeks. While adjusting daily transfers and case detection impacted case distribution across facilities, aggressive vaccination measures result in the fewest number of infections. This finding indicates that mumps outbreaks can be minimized or entirely prevented through vaccination. Investing in a third MMR dose incurs significant benefits, both to the health of an already vulnerable detainee population and to the public health system as a whole.