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Background: Childhood tuberculosis (TB) is acquired after exposure to an infectious TB case, often within the household. We prospectively screened children 6-59 months of age, exposed and unexposed to an infectious TB case within the same household, for latent tuberculosis infection (LTBI), in Dar es Salaam, Tanzania., Methods: We collected medical data and clinical specimens (to evaluate for helminths, TB and HIV coinfections) and performed physical examinations at enrollment and at 3-month and 6-month follow-up surveys. LTBI was assessed using QuantiFERON-TB Gold (QFT) at enrollment and at 3 months., Results: In total, 301 children had complete data records (186 with TB exposure and 115 without known TB exposure). The median age of children was 26 months (range: 6-58); 52% were females, and 4 were HIV positive. Eight children (3%) developed TB during the 6-month follow-up. We found equal proportions of children with LTBI among those with and without exposure: 20% (38/186) versus 20% (23/115) QFT-positive, and 2% (4/186) versus 4% (5/115) indeterminate QFT. QFT conversion rate was 7% (22 children) and reversion 8% (25 children). Of the TB-exposed children, 72% initiated isoniazid preventive therapy, but 61% of parents/caregivers of children with unknown TB exposure and positive QFT refused isoniazid preventive therapy., Conclusions: In this high burden TB setting, TB exposure from sources other than the household was equally important as household exposure. Nearly one third of eligible children did not receive isoniazid preventive therapy. Evaluation for LTBI in children remains an important strategy for controlling TB but should not be limited to children with documented TB exposure.

Background: Helminth infections can negatively affect the immunologic host control, which may increase the risk of progression from latent Mycobacterium tuberculosis infection to tuberculosis (TB) disease and alter the clinical presentation of TB. We assessed the prevalence and determined the clinical relevance of helminth co-infection among TB patients and household contact controls in urban Tanzania., Methodology: Between November 2013 and October 2015, we enrolled adult (≥18 years) sputum smear-positive TB patients and household contact controls without TB during an ongoing TB cohort study in Dar es Salaam, Tanzania. We used Baermann, FLOTAC, Kato-Katz, point-of-care circulating cathodic antigen, and urine filtration to diagnose helminth infections. Multivariable logistic regression models with and without random effects for households were used to assess for associations between helminth infection and TB., Principal Findings: A total of 597 TB patients and 375 household contact controls were included. The median age was 33 years and 60.2% (585/972) were men. The prevalence of any helminth infection among TB patients was 31.8% (190/597) and 25.9% (97/375) among controls. Strongyloides stercoralis was the predominant helminth species (16.6%, 161), followed by hookworm (9.0%, 87) and Schistosoma mansoni (5.7%, 55). An infection with any helminth was not associated with TB (adjusted odds ratio (aOR) 1.26, 95% confidence interval (CI): 0.88-1.80, p = 0.22), but S. mansoni infection was (aOR 2.15, 95% CI: 1.03-4.45, p = 0.040). Moreover, S. mansoni infection was associated with lower sputum bacterial load (aOR 2.63, 95% CI: 1.38-5.26, p = 0.004) and tended to have fewer lung cavitations (aOR 0.41, 95% CI: 0.12-1.16, p = 0.088)., Conclusions/significance: S. mansoni infection was an independent risk factor for active TB and altered the clinical presentation in TB patients. These findings suggest a role for schistosomiasis in modulating the pathogenesis of human TB. Treatment of helminths should be considered in clinical management of TB and TB control programs.

Introduction: Decentralization of Directly Observed Treatment (DOT) for tuberculosis (TB) to the community (home-based DOT) has improved the coverage of TB treatment and reduced the burden to the health care facilities (facility-based DOT). We aimed to compare TB treatment outcomes in home-based and facility-based DOT under programmatic conditions in an urban setting with a high TB burden., Methodology: A retrospective analysis of a cohort of adult TB patients (≥15 years) routinely notified between 2010 and 2013 in two representative TB sub-districts in the Temeke district, Dar es Salaam, Tanzania. We assessed differences in treatment outcomes by calculating Risk Ratios (RRs). We used logistic regression to assess the association between DOT and treatment outcomes., Results: Data of 4,835 adult TB patients were analyzed, with a median age of 35 years, 2,943 (60.9%) were men and TB/HIV co-infection prevalence of 39.9%. A total of 3,593 (74.3%) patients were treated under home-based DOT. Patients on home-based DOT were more likely to die compared to patients on facility-based DOT (RR 2.04, 95% Confidence Interval [95% CI]: 1.52-2.73), and more likely to complete TB treatment (RR 1.14, 95% CI: 1.06-1.23), but less likely to have a successful treatment outcome (RR 0.94, 95% CI: 0.92-0.97). Home-based DOT was preferred by women (adjusted Odds Ratio [aOR] 1.55, 95% CI: 1.34-1.80, p<0.001), older people (aOR 1.01 for each year increase, 95% CI: 1.00-1.02, p = 0.001) and patients with extra-pulmonary TB (aOR 1.45, 95% CI: 1.16-1.81, p = 0.001), but less frequently by patients on a retreatment regimen (aOR 0.12, 95% CI: 0.08-0.19, p<0.001)., Conclusions/significance: TB patients under home-based DOT had more frequently risk factors of death such as older age, HIV infection and sputum smear-negative TB, and had higher mortality compared to patients under facility-based DOT. Further operational research is needed to monitor the implementation of DOT under programmatic conditions.