Analysis of a large SARS-CoV-2 (Alpha) outbreak in a Catalan prison using conventional and genomic epidemiology.

Enforcing strict protocols that prevent transmission of airborne infections in prisons is challenging. We examine a large SARS-CoV-2 outbreak in a Catalan penitentiary center from February-March 2021, prior to vaccination deployment. The aim was to describe the evolution of the outbreak using classical and genomic epidemiology and the containment strategy applied. The outbreak was initially detected in one module but spread to four, infecting 7 staff members and 140 incarcerated individuals, 6 of whom were hospitalized (4.4%). Genomic analysis confirmed a single origin (B.1.1.7). Contact tracing identified transmission vectors between modules and prevented further viral spread. In future similar scenarios, the control strategy described here may help limiting transmission of airborne infections in correctional settings.

Late diagnosis of HIV infection among prisoners.

HIV-risk populations are over-represented in prisons. It is very important to identify late HIV infection diagnosis in this setting from a public health perspective. The objectives of this study are to estimate the prevalence of late diagnosis and identify the predictive factors among inmates of two prisons in Barcelona from 2010 to 2012, and to review late diagnosis in other prisons. A cross-sectional study design was used on inmates with newly-diagnosed HIV infection. Less than 350 CD4 lymphocytes/µl was considered late diagnosis. A Medline search was performed. Of the 3,933 total inmates, 1.2% (n = 47) were diagnosed with HIV infection, 1.7% from Prison A and 0.6% from Prison B (p < 0.001). Late diagnosis occurred in 47.7% of cases. A higher number of cases with late diagnosis were found in Prison A, among the immigrant population, and among intravenous drug users (p = 0.026, p = 0.007, p = 0.03, respectively). The proportion of late diagnosis decreased from 60% in 2010, to 44.4% in 2011 and 20% in 2012 (p = 0.05). The multivariate analysis confirmed an association between late diagnosis and immigrant status (OR: 7.85; 95% CI: 1.8-34.13) and the declining prevalence (p = 0.032). This is the first study to estimate late diagnosis in a prison population. Late diagnosis occurs mainly among the immigrant inmate population. The prison can serve as an opportunity to identify and treat HIV infection among people who have little contact with health services, thus avoiding further transmission.