Search

Background: Correctional centres provide ideal conditions for tuberculosis (TB) transmission and disease progression. Despite the high TB incidence and incarceration rate in South Africa, data from South African correctional centres are scarce. Thus, the study evaluated TB diagnosis, treatment initiation and completion, and identified prevalent Mycobacterium tuberculosis strains among detainees entering a South African correctional centre., Methods: This study was a prospective observational study that enrolled participants between February and September 2017 from a correctional centre located in the Western Cape, South Africa. All adult male detainees who tested positive for TB during admission screening were eligible to participate in the study. Sputum samples from enrolled participants underwent smear microscopy and culture. Strain typing was performed on culture-positive samples. The time between specimen collection and diagnosis, the time between diagnosis and treatment initiation, and the proportion of detainees completing TB treatment at the correctional centre were calculated., Results: During the study period, 130 TB cases were detected through routine admission screening (126 male, 2 female, 2 juvenile). Out of the 126 eligible male detainees, 102 were enrolled in the study (81%, 102/126). All TB cases were detected within 30 hrs of admission screening. The majority (78%, 80/102) of participants started treatment within 48 hrs of TB diagnosis. However, only 8% (9/102) of participants completed treatment at the correction centre. Sputa from 90 of the 102 participants were available for smear and culture. There was a high smear positivity, with 49% (44/90) of isolates being smear positive. The Beijing family was the most frequent lineage (55.2%) in the study., Conclusion: The strengths of the current TB control efforts at the correctional centre include rapid detection of cases through admission screening and prompt treatment initiation. However, a high number of detainees exiting before treatment completion highlights the need to strengthen links between correctional TB services and community TB services to ensure detainees complete TB treatment after release and prevent TB transmission., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Baird et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Tuberculosis (TB) infection caused by Mycobacterium tuberculosis (Mtb) is still a persistent global health problem, particularly in developing countries. The World Health Organization (WHO) reported a mortality rate of about 1.8 million worldwide due to TB complications in 2015. The Bacillus Calmette-Guérin (BCG) vaccine was introduced in 1921 and is still widely used to prevent TB development. This vaccine offers up to 80% protection against various forms of TB; however its efficacy against lung infection varies among different geographical settings. Devastatingly, the development of various forms of drug-resistant TB strains has significantly impaired the discovery of effective and safe anti-bacterial agents. Consequently, this necessitated discovery of new drug targets and novel anti-TB therapeutics to counter infection caused by various Mtb strains. Importantly, various factors that contribute to TB development have been identified and include bacterial resuscitation factors, host factors, environmental factors and genetics. Furthermore, Mtb-induced epigenetic changes also play a crucial role in evading the host immune response and leads to bacterial persistence and dissemination. Recently, the application of GeneXpert MTB/RIF ® to rapidly diagnose and identify drug-resistant strains and discovery of different molecular markers that distinguish between latent and active TB infection has motivated and energised TB research. Therefore, this review article will briefly discuss the current TB state, highlight various mechanisms employed by Mtb to evade the host immune response as well as to discuss some modern molecular techniques that may potentially target and inhibit Mtb replication., (Copyright © 2018. Published by Elsevier Ltd.)

South Africa implemented Xpert MTB/RIF as the initial diagnostic test for pulmonary tuberculosis (TB). Xpert MTB/RIF's accuracy for diagnosing extrapulmonary tuberculosis (EPTB) was investigated. EPTB specimens (n = 7,916) from hospitalized patients received over a 6-month period at a high-throughput TB referral laboratory in Johannesburg were investigated. Large-volume specimens were centrifuged, tissue biopsy specimens homogenized, and all specimens checked for growth of contaminating bacteria on blood agar. Contaminated samples received NALC-NaOH (N-acetyl-l-cysteine-sodium hydroxide) decontamination prior to liquid culture. Residual specimens (volumes > 1 ml) after inoculation of culture (n = 1,175) were tested using the Xpert MTB/RIF sputum protocol. Using culture as the reference, Xpert MTB/RIF's overall sensitivity was 59% (95% confidence interval [95% CI], 53% to 65%) and specificity was 92% (CI, 90% to 94%), with the highest sensitivities of 91% (95% CI, 78% to 97%) for pus, 80% (95% CI, 56% to 94%) for lymph node aspirates, and 51% (95% CI, 44% to 58%) for fluids (ascitic, 59%; pleural, 47%). A difference in sensitivities was noticed between specimens classified as having a thick (87% [95% CI, 76% to 94%]) versus clear (watery) (48% [95% CI, 36% to 61%]) appearance. This was unchanged with traces of blood (52% [95% CI, 44% to 60%]) or precentrifugation (57% [95% CI, 28% to 82%]) among clear specimens. Xpert MTB/RIF generated an additional 124 specimen results that were contaminated by Mycobacterial Growth Indicator Tubes (MGIT; 10.5%) and diagnosed rifampin (RIF) resistance earlier (9.6% [25/260]). Xpert MTB/RIF's performance on EPTB specimens provides very promising results and should be considered for incorporation into national TB guidelines. Xpert MTB/RIF is less affected by contaminating bacteria and reduces laboratory labor and diagnostic delay compared to traditional methods., (Copyright © 2014, American Society for Microbiology. All Rights Reserved.)