Surveillance of Viral Respiratory Infections within Maximum-Security Prison, Australia
Emerging Infectious Diseases – 2025, 31, 8.
Nicolas M. Legrand, Rowena A. Bull, Behzad Hajarizadeh, Andrew R. Lloyd, Kirsty Johnston, Katya Issa, Christine Harvey, Alicia Arnott, Dominic E. Dwyer,
Vitali Sintchenko, Luke Grant, Gregory J. Dore, John Kaldor, Marianne Martinello
Abstract:
Limited surveillance data have hindered understanding of SARS-CoV-2 transmission within prisons. We integrated routine surveillance data with viral sequencing to investigate transmission dynamics and associated factors during
a Delta variant outbreak in a maximum-security prison in Sydney, New South Wales, Australia. Infection incidence and associated factors were determined by using person-time and Cox regression. We generated transmission chains by integrating epidemiologic and viral sequencing data. Of 1,562 patients, SARS-CoV-2 infection was diagnosed in 169 (11%), predominantly acquired in prison and asymptomatic. Prison-wide testing identified substantial unrecognized transmission, and 4 subvariants indicated multiple viral introductions. Infection was associated with housing location, having a cellmate (regardless of infection status), and vaccination status. Our findings underscore the inadequacy of symptom-based testing and the efficacy of entry-quarantine, strategic housing, extensive testing, and vaccination in reducing transmission. This integrated approach to surveillance and genomic sequencing offers a valuable model for enhancing infectious disease surveillance in correctional settings.