For each participant with a positive cough screen, spot and morning sputum samples were collected in the prison health clinic. Acid-fast bacilli (AFB) smear microscopy was performed with regular light microscopy using the Ziehl-Neelsen (ZN) technique.24 The remaining portions of the samples were transported daily in ice boxes to the regional public health laboratory, which was about 500 m away. The two sputum samples were pooled in a single container and stored at −20°C until transport to Armauer Hansen Research Institute (AHRI) in Addis Ababa.
External quality control was performed for all slides by an independent, experienced laboratory technician at AHRI who was blinded to the AFB microscopy and Xpert results.
HIV screening was performed according to the national testing algorithm. Briefly, blood samples from finger-pricks were tested first with HIV (1+2) Antibody Colloidal Gold (Shanghai Kehua Bioengineering, Shanghai, China); positive samples were confirmed using Stat-Pak (Chembio, Medford, Brookhaven, NY, USA), while discordant results were resolved using HIV-1/2 Unigold Recombinant Assay (Trinity Biotech, Bray, Ireland).
External quality control was performed for all slides by an independent, experienced laboratory technician at AHRI who was blinded to the AFB microscopy and Xpert results.
HIV screening was performed according to the national testing algorithm. Briefly, blood samples from finger-pricks were tested first with HIV (1+2) Antibody Colloidal Gold (Shanghai Kehua Bioengineering, Shanghai, China); positive samples were confirmed using Stat-Pak (Chembio, Medford, Brookhaven, NY, USA), while discordant results were resolved using HIV-1/2 Unigold Recombinant Assay (Trinity Biotech, Bray, Ireland).