The Risk of Tuberculosis among Populations Living in Slum Settings: a Systematic Review and Meta-analysis

Abstract

According to the WHO, half of the 10.4 million incident cases of TB in 2016 came from five countries where 20–50% of the urban population live in slums. Crowded living conditions and limited access to healthcare further contribute to the burden of TB in urban slums. This article aims to assess the odds of the burden of TB in urban slums through a systematic review and meta-analysis. Four electronic databases were searched for studies published between 1993 and 2017, with TB defined as at least one sputum smear-positive. The review followed the PRISMA protocol and information was extracted from articles for a full-text review to determine eligibility. Odds ratios were calculated for studies reporting sputum smear-positive TB cases in slum settings with national incidence as a comparison. Summary estimates were calculated using the random effects model (95% CI) and publication bias was assessed through funnel plot analysis. A quality assessment of included articles was also conducted. This meta-analysis was conducted across three categories: (1) across all 22 studies, (2) studies utilizing Active Case Finding, and (3) studies conducted in a high TB-HIV setting. The odds of sputum smear-positive TB were significantly higher across all three categories of analysis. Compared with national TB incidence rates, the combined odds ratio of smear-positive TB within slums was 2.96 (2.84, 3.09; p < 0.01). The combined odds ratio for smear-positive TB with active case finding across 15 studies was 2.85 (2.71, 2.99; p < 0.01). Among the 11 studies that reported incidence of smear-positive TB with prevalent TB-HIV coinfection in the community, the combined odds ratio for slum residents with the random effects model was 2.48 (2.34, 2.63; p < 0.01). Using Egger’s funnel plot, publication bias was not detected within the three categories of analysis. The findings of this analysis indicate that the odds of developing TB are almost five times as great in urban slums. Reaching the most vulnerable and often overlooked groups in slums is crucial to achieving the SDGs and End TB Strategy by 2035.