Theresa Ryckman1, Elizabeth T Chin2, Lea Prince3, David Leidner4, Elizabeth Long3, David M Studdert5, Joshua A Salomon3, Fernando Alarid-Escudero6, Jason R Andrews7, Jeremy D Goldhaber-Fiebert3. 1. Stanford Health Policy, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA. Electronic address: tessryckman@gmail.com. 2. Department of Biomedical Data Science, Stanford University, Stanford, CA, USA. 3. Stanford Health Policy, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA. 4. California Department of Corrections and Rehabilitation, Elk Grove, CA, USA. 5. Stanford Health Policy, Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA; Stanford Law School, Stanford, CA, USA. 6. Division of Public Administration, Center for Research and Teaching in Economics, Aguascalientes, Mexico. 7. Department of Medicine, Stanford University School of Medicine, Palo Alto, CA, USA.
Abstract
BACKGROUND: Residents of prisons have experienced disproportionate COVID-19-related health harms. To control outbreaks, many prisons in the USA restricted in-person activities, which are now resuming even as viral variants proliferate. This study aims to use mathematical modelling to assess the risks and harms of COVID-19 outbreaks in prisons under a range of policies, including resumption of activities. METHODS: We obtained daily resident-level data for all California state prisons from Jan 1, 2020, to May 15, 2021, describing prison layouts, housing status, sociodemographic and health characteristics, participation in activities, and COVID-19 testing, infection, and vaccination status. We developed a transmission-dynamic stochastic microsimulation parameterised by the California data and published literature. After an initial infection is introduced to a prison, the model evaluates the effect of various policy scenarios on infections and hospitalisations over 200 days. Scenarios vary by vaccine coverage, baseline immunity (0%, 25%, or 50%), resumption of activities, and use of non-pharmaceutical interventions (NPIs) that reduce transmission by 75%. We simulated five prison types that differ by residential layout and demographics, and estimated outcomes with and without repeated infection introductions over the 200 days. FINDINGS: If a viral variant is introduced into a prison that has resumed pre-2020 contact levels, has moderate vaccine coverage (ranging from 36% to 76% among residents, dependent on age, with 40% coverage for staff), and has no baseline immunity, 23-74% of residents are expected to be infected over 200 days. High vaccination coverage (90%) coupled with NPIs reduces cumulative infections to 2-54%. Even in prisons with low room occupancies (ie, no more than two occupants) and low levels of cumulative infections (ie, <10%), hospitalisation risks are substantial when these prisons house medically vulnerable populations. Risks of large outbreaks (>20% of residents infected) are substantially higher if infections are repeatedly introduced. INTERPRETATION: Balancing benefits of resuming activities against risks of outbreaks presents challenging trade-offs. After achieving high vaccine coverage, prisons with mostly one-to-two-person cells that have higher baseline immunity from previous outbreaks can resume in-person activities with low risk of a widespread new outbreak, provided they maintain widespread NPIs, continue testing, and take measures to protect the medically vulnerable. FUNDING: Horowitz Family Foundation, National Institute on Drug Abuse, Centers for Disease Control and Prevention, National Science Foundation, Open Society Foundation, Advanced Micro Devices.
BACKGROUND: Residents of prisons have experienced disproportionate COVID-19-related health harms. To control outbreaks, many prisons in the USA restricted in-person activities, which are now resuming even as viral variants proliferate. This study aims to use mathematical modelling to assess the risks and harms of COVID-19 outbreaks in prisons under a range of policies, including resumption of activities. METHODS: We obtained daily resident-level data for all California state prisons from Jan 1, 2020, to May 15, 2021, describing prison layouts, housing status, sociodemographic and health characteristics, participation in activities, and COVID-19 testing, infection, and vaccination status. We developed a transmission-dynamic stochastic microsimulation parameterised by the California data and published literature. After an initial infection is introduced to a prison, the model evaluates the effect of various policy scenarios on infections and hospitalisations over 200 days. Scenarios vary by vaccine coverage, baseline immunity (0%, 25%, or 50%), resumption of activities, and use of non-pharmaceutical interventions (NPIs) that reduce transmission by 75%. We simulated five prison types that differ by residential layout and demographics, and estimated outcomes with and without repeated infection introductions over the 200 days. FINDINGS: If a viral variant is introduced into a prison that has resumed pre-2020 contact levels, has moderate vaccine coverage (ranging from 36% to 76% among residents, dependent on age, with 40% coverage for staff), and has no baseline immunity, 23-74% of residents are expected to be infected over 200 days. High vaccination coverage (90%) coupled with NPIs reduces cumulative infections to 2-54%. Even in prisons with low room occupancies (ie, no more than two occupants) and low levels of cumulative infections (ie, <10%), hospitalisation risks are substantial when these prisons house medically vulnerable populations. Risks of large outbreaks (>20% of residents infected) are substantially higher if infections are repeatedly introduced. INTERPRETATION: Balancing benefits of resuming activities against risks of outbreaks presents challenging trade-offs. After achieving high vaccine coverage, prisons with mostly one-to-two-person cells that have higher baseline immunity from previous outbreaks can resume in-person activities with low risk of a widespread new outbreak, provided they maintain widespread NPIs, continue testing, and take measures to protect the medically vulnerable. FUNDING: Horowitz Family Foundation, National Institute on Drug Abuse, Centers for Disease Control and Prevention, National Science Foundation, Open Society Foundation, Advanced Micro Devices.
Authors: Yiran E Liu; Christopher LeBoa; Marcela Rodriguez; Beruk Sherif; Chrisele Trinidad; Michael Del Rosario; Sophie Allen; Christine Clifford; Jennifer Redding; Wei-Ting Chen; Lisa G Rosas; Carlos Morales; Alexander Chyorny; Jason R Andrews Journal: Front Public Health Date: 2022-06-14
Authors: Elizabeth T Chin; David Leidner; Yifan Zhang; Elizabeth Long; Lea Prince; Stephanie J Schrag; Jennifer R Verani; Ryan E Wiegand; Fernando Alarid-Escudero; Jeremy D Goldhaber-Fiebert; David M Studdert; Jason R Andrews; Joshua A Salomon Journal: Clin Infect Dis Date: 2022-08-24 Impact factor: 20.999
Authors: Yiran E Liu; Jillian Oto; John Will; Christopher LeBoa; Alexis Doyle; Neil Rens; Shelley Aggarwal; Iryna Kalish; Marcela Rodriguez; Beruk Sherif; Chrisele Trinidad; Michael Del Rosario; Sophie Allen; Robert Spencer; Carlos Morales; Alexander Chyorny; Jason R Andrews Journal: Prev Med Rep Date: 2022-03-15