Strategies to detect and manage latent tuberculosis infection among household contacts of pulmonary TB patients in high TB burden countries - a systematic review and meta-analysis

Abstract

Objective: To summarise latent tuberculosis infection (LTBI) management strategies among household contacts of bacteriologically confirmed pulmonary tuberculosis (TB) patients in high-TB burden countries.

Methods: PubMed/MEDLINE (NCBI) and Scopus were searched (January 2006 to December 2021) for studies reporting primary data on LTBI management. Study selection, data management and data synthesis were protocol-driven (PROSPERO-CRD42021208715). Primary outcomes were the proportions of LTBI, initiating and completing tuberculosis preventive treatment (TPT). Reported factors influencing the LTBI care cascade were qualitatively synthesised.

Results: From 3694 unique records retrieved, 58 studies from 23 countries were included. Most identified contacts were screened (median 99%, interquartile range [IQR] 82%-100%; 46 studies). Random-effects meta-analysis yielded pooled proportions for: LTBI 41% (95% confidence interval [CI] 33%-49%; 21,566 tested contacts); TPT initiation 91% (95% CI 79%-97%; 129,573 eligible contacts, 34 studies); TPT completion 65% (95% CI 54%-74%; 108,679 TPT-initiated contacts, 28 studies). Heterogeneity was significant (I² ≥ 95%-100%) and could not be explained in subgroup analyses. Median proportions (IQR) were: LTBI 44% (28%-59%); TPT initiation 86% (60%-100%); TPT completion 68% (44%-82%). Nine broad themes related to diagnostic testing, health system structure and functions, risk perception, documentation and adherence were considered likely to influence the LTBI care cascade.

Conclusion: The proportions of household contacts screened, detected with LTBI and initiated on TPT, though variable was high, but the proportions completing TPT were lower indicating current strategies used for LTBI management in high TB burden countries are not sufficient.

Keywords: TB preventive therapy; diagnosis; high TB burden settings; household contacts; isoniazid preventive therapy; latent TB infection; screening; treatment; tuberculosis.