Rates of SARS-CoV-2 transmission between and into California state prisons

Area of Science:

• Epidemiology
• Public Health
• Mathematical Modeling

Background:

• Correctional facilities are high-risk environments for SARS-CoV-2 amplification and health disparities.
• Inter-facility transmission within the California prison system has driven major outbreaks.
• Correctional staff are identified as key vectors for introducing SARS-CoV-2 into prisons.

Approach:

• Utilized publicly available data and a mechanistic Hawkes process model to estimate SARS-CoV-2 transmission dynamics.
• Quantified transmission rates from communities to staff and residents, within facilities, and between distinct prison facilities.
• Employed nested models for hypothesis testing, comparing complex transmission scenarios with simplified models.

Key Points:

• Transmission between correctional staff across different facilities significantly contributes to disease spread.
• Correctional staff act as a critical link for transmitting SARS-CoV-2 between incarcerated populations and external communities.
• Findings underscore the inadequacy of limited interventions like screening and vaccination alone.

Conclusions:

• Large-scale decarceration is a necessary measure to mitigate widespread SARS-CoV-2 transmission in correctional settings.
• Interventions focused solely on staff screening or vaccination are unlikely to prevent substantial outbreaks.
• Addressing the root causes of transmission, including facility density, is paramount for public health within and beyond prisons.