Xpert MTB/RIF Assay Shortens Airborne Isolation for Hospitalized Patients With Presumptive Tuberculosis in the United States

Background. In the United States, individuals with presumptive pulmonary tuberculosis are placed in airborne infection isolation (AII) and assessed by smear microscopy on 3 respiratory specimens collected 8–24 hours apart. Xpert MTB/RIF assay (Xpert) on 1, 2, or 3 specimens may be more efficient for determining AII discontinuation

The Impact of Expanded Testing for Multidrug Resistant Tuberculosis Using Geontype MTBDRplus in South Africa: An Observational Cohort Study

Globally, multidrug resistant tuberculosis (MDR-TB) remains underdiagnosed. The Genotype MTBDRplus®, a rapid drug susceptibility testing (DST) assay used to detect resistance to isoniazid and rifampicin in the diagnosis of MDR-TB, has good diagnostic accuracy, but its impact on patient outcomes in routine practice is unproven. We assessed the clinical impact of routine DST using MTBDRplus in a single health district in South Africa

Xpert MTB/RIF as a Measure of Sputum Bacillary Burden. Variation by HIV Status and Immunosuppression

Rationale: Xpert MTB/RIF cycle threshold values are a measure of sputum mycobacterial burden. Data on the impact of HIV infection and immunosuppression on this measure are limited

Time to Treatment and Patient Outcomes among TB Suspects Screened by a Single Point-of-Care Xpert MTB/RIF at a Primary Care Clinic in Johannesburg, South Africa

In December 2010, the World Health Organization recommended a single Xpert MTB/RIF assay as the initial diagnostic in people suspected of HIV-associated or drug resistant tuberculosis. Few data are available on the impact of this recommendation on patient outcomes. We describe the diagnostic follow-up, clinical characteristics and outcomes of a cohort of tuberculosis suspects screened using a single point-of-care Xpert

Prevalence of latent tuberculosis infection and predictive factors in an urban informal settlement in Johannesburg, South Africa: a cross-sectional study

Abstract Background South Africa has one of the highest burdens of latent tuberculosis infection (LTBI) in high-risk populations such as young children, adolescents, household contacts of TB cases, people living with HIV, gold miners and health care workers, but little is known about the burden of LTBI in its general population. Methods Using a community-based survey with random sampling, we examined the burden of LTBI in an urban township of Johannesburg and investigated factors associated with LTBI. The outcome of LTBI was based on TST positivity, with a TST considered positive if the induration was ≥5 mm in people living with HIV or ≥10 mm in those with unknown or HIV negative status. We used bivariate and multivariable logistic regression to identify factors associated with LTBI Results The overall prevalence of LTBI was 34.3 (95 % CI 30.0, 38.8 %), the annual risk of infection among children age 0–14 years was 3.1 % (95 % CI 2.1, 5.2). LTBI was not associated with HIV status. In multivariable logistic regression analysis, LTBI was associated with age (OR = 1.03 for every year increase in age, 95 % CI = 1.01–1.05), male gender (OR = 2.70, 95 % CI = 1.55–4.70), marital status (OR = 2.00, 95 % CI = 1.31–3.54), and higher socio-economic status (OR = 2.11, 95 % CI = 1.04–4.31). Conclusions The prevalence of LTBI and the annual risk of infection with M. tuberculosis is high in urban populations, especially in men, but independent of HIV infection status. This study suggests that LTBI may be associated with higher SES, in contrast to the well-established association between TB disease and poverty

Prevalence of latent tuberculosis infection and predictive factors in an urban informal settlement in Johannesburg, South Africa: a cross-sectional study

Abstract Background South Africa has one of the highest burdens of latent tuberculosis infection (LTBI) in high-risk populations such as young children, adolescents, household contacts of TB cases, people living with HIV, gold miners and health care workers, but little is known about the burden of LTBI in its general population. Methods Using a community-based survey with random sampling, we examined the burden of LTBI in an urban township of Johannesburg and investigated factors associated with LTBI. The outcome of LTBI was based on TST positivity, with a TST considered positive if the induration was ≥5 mm in people living with HIV or ≥10 mm in those with unknown or HIV negative status. We used bivariate and multivariable logistic regression to identify factors associated with LTBI Results The overall prevalence of LTBI was 34.3 (95 % CI 30.0, 38.8 %), the annual risk of infection among children age 0–14 years was 3.1 % (95 % CI 2.1, 5.2). LTBI was not associated with HIV status. In multivariable logistic regression analysis, LTBI was associated with age (OR = 1.03 for every year increase in age, 95 % CI = 1.01–1.05), male gender (OR = 2.70, 95 % CI = 1.55–4.70), marital status (OR = 2.00, 95 % CI = 1.31–3.54), and higher socio-economic status (OR = 2.11, 95 % CI = 1.04–4.31). Conclusions The prevalence of LTBI and the annual risk of infection with M. tuberculosis is high in urban populations, especially in men, but independent of HIV infection status. This study suggests that LTBI may be associated with higher SES, in contrast to the well-established association between TB disease and poverty

A proposed novel framework for monitoring and evaluation of the cascade of HIV-associated TB care at the health facility level

Introduction: The rapid and accurate diagnosis of HIV-associated tuberculosis (TB), timely initiation of curative or preventative treatment and assurance of favourable treatment outcomes is a complex process. The current system of monitoring and reporting TB diagnosis and treatment does not include several key aspects of the care cascade, and may obscure systematic bottlenecks, inefficiencies or sources of sub-optimal care. Methods: We critically reviewed the current World Health Organizations recommended system of monitoring and reporting, and identified the following key deficiencies that could limit the ability of healthcare workers to identify structural problems in the provision of TB/HIV care. Results: We identified the following key deficiencies in the current monitoring and evaluation system: (1) an emphasis on national-level reporting and programmatic analysis results in a loss of granularity; (2) the absence of a general framework to anchor indicators in relation to one another as well as the overall goals for TB/HIV collaborative activities; (3) de-linking of TB treatment indicators from those for screening and diagnosis; (4) few indicators are tied to suggested times for completion of an activity. We defined three distinct stages comprising the cascade of HIV-associated TB diagnosis and treatment: (1) Screening & Diagnosis, (2) Treatment and (3) Preventive Therapy. We detailed major steps within each stage, described potential sources of variability, and proposed data elements, process indicators, main outcomes, and retention calculations for each stage. Conclusions: This proposed framework of monitoring is novel in its focus on a cohort experience through the entire scope of the care cascade from screening and TB diagnosis through curative or preventive treatment. This approach can be applied to all settings at clinic, district or national level, and used to identify crucial areas for improvement in order to maximize health outcomes for all those affected by the dual epidemics of TB and HIV

Association between monocyte-to-lymphocyte ratio and tuberculin skin test positivity in HIV-positive adults

BACKGROUND: The tuberculin skin test (TST) identifies individuals at high risk of developing tuberculosis (TB) but poses many challenges. The blood monocyte-to-lymphocyte ratio (MLR) could be an alternative, as extremes in MLR have been associated with increased risk of TB disease. METHODS: At a primary care clinic in Johannesburg, a differential white blood cell count and TST was performed in adults starting antiretroviral treatment (ART) without symptoms suggestive of active TB. RESULTS: Of 259 participants, 171 had valid results of whom 30% (51/171) were TST positive and the median MLR was 0.18 (IQR 0.13–0.28). The MLR distribution differed between CD4 count categories (p < 0.01), with a broader range of values in TST negative participants with a low CD4 count (≤ 250 cells/mm(3)), likely reflecting HIV immunosuppression. MLR was associated with a positive TST (OR 0.78 per 0.1 increase, 95% CI 0.59, 0.97) in bivariate analysis but not in multivariate regression analysis (aOR 0.83 for every 0.1 increase, 95% CI 0.60, 1.08). CONCLUSION: In ART-naïve adults without symptoms suggestive of active TB, MLR was not independently associated with TST positivity and is thus unlikely to be a useful alternative to TST. Future research should focus on development of a cheap, simple and accurate biomarker to identify those people benefiting most from preventive TB therapy