The impact of sputum quality on Xpert positivity in active case-finding for TB.

BACKGROUND: Studies evaluating sputum quality and Xpert® MTB/RIF positivity in the context of active case finding are scarce. We aimed to determine whether sputum quality is associated with Xpert positivity and whether the association differed according to demographic and clinical characteristics.METHODS: A cross-sectional analysis using data from a mass screening programme in Brazilian prisons was conducted from 2017 to 2021. We administered a standardised questionnaire, obtained a chest X-ray and collected a spot sputum sample for Xpert testing. Sputum quality was classified as 'salivary', 'mucoid/mucopurulent' or 'blood-stained'. We used log binomial regressions to estimate the relationship between sputum quality and Xpert positivity, assessing interactions with participant characteristics.RESULTS: Among 4,368 participants for whom sputum quality was assessed, 957 (21.9%) produced salivary specimens, 3,379 (77.4%) had mucoid/mucopurulent sputum and 32 (0.7%) had blood-stained sputum. Xpert positivity was higher among those with mucoid/mucopurulent sputum than among those with salivary samples (12.0% vs. 3.7%). Mucopurulent sputum independently predicted Xpert positivity among individuals with and without symptoms, current smoking and abnormal chest radiographs on CAD4TB.CONCLUSIONS: In our study, sputum appearance independently predicted Xpert positivity, and could be used together with chest X-ray and symptom screening to inform use of Xpert in individual or pooled testing.

Low BMI increases all-cause mortality rates in patients with drug-resistant TB.

BACKGROUND: Loss to follow-up (LTFU) is common among patients with drug-resistant TB (DR-TB) receiving second-line TB treatment; however, little is known about outcomes after LTFU, including mortality.OBJECTIVE: To determine rates of and factors associated with all-cause mortality among patients with DR-TB who were LTFU.METHODS: Retrospective cohort study of adult patients with DR-TB in Georgia who initiated second-line TB treatment during 2011-2014 and were LTFU. Survival analyses were used to estimate all-cause mortality rates and adjusted hazard ratios (aHR).RESULTS: During 2011-2014, 2,437 second-line treatment episodes occurred and 695 patients were LTFU. Among 695 LTFU patients, 143 (21%) died during 2,686 person-years (PY) post-LTFU (all-cause mortality rate 5.1%, 95% CI 4.3-6.0 per 100 PY). In multivariable analysis, low weight (BMI < 18.5 kg/m²) at treatment initiation (aHR 3.2, 95% CI 2.2-4.7), return to treatment after LTFU (aHR 3.1, 95% CI 2.2-4.4), <12 months of treatment (aHR 2.4, 95% CI 1.4-4.1) and a pre-LTFU positive culture (aHR 3.3, 95% CI 2.2-4.9) were associated with all-cause mortality.CONCLUSION: High all-cause mortality occurred among patients with DR-TB after LTFU despite a low HIV prevalence. Providing additional assistance for patients during DR-TB treatment to prevent LTFU and use of new and shorter treatment regimens may reduce mortality among LTFU.

Convergence of non-communicable diseases and tuberculosis: a two-way street?

The intersection of tuberculosis (TB) with non-communicable diseases (NCDs), including diabetes mellitus (DM), chronic lung disease (CLD), and cardiovascular disease (CVD), has emerged as a critical clinical and public health challenge. Rapidly expanding NCD epidemics threaten TB control in low- and middle-income countries, where the prevention and treatment of TB disease remain a great burden. However, to date, the notion that TB may adversely impact NCD risk and severity has not been well explored. This review summarizes biomedical hypotheses, findings from animal models, and emerging epidemiologic data related to the progression of DM, CLD and CVD during and after active TB disease. We conclude that there is sufficient empirical evidence to justify a greater research emphasis on the syndemic interaction between TB and NCD.