Global guidelines for treatment of tuberculosis among persons living with HIV: unresolved issues

Bayesian modeling of spatiotemporal patterns of TB-HIV co-infection risk in Kenya

Background

Tuberculosis (TB) and Human Immunodeficiency Virus (HIV) diseases are globally acknowledged as a public health challenge that exhibits adverse bidirectional relations due to the co-epidemic overlap. To understand the co-infection burden we used the case notification data to generate spatiotemporal maps that described the distribution and exposure hypotheses for further epidemiologic investigations in areas with unusual case notification levels.

Methods

We analyzed the TB and TB-HIV case notification data from the Kenya national TB control program aggregated for forty-seven counties over a seven-year period (2012–2018). Using spatiotemporal poisson regression models within the Integrated Nested Laplace Approach (INLA) paradygm, we modeled the risk of TB-HIV co-infection. Six competing models with varying space-time formulations were compared to determine the best fit model. We then assessed the geographic patterns and temporal trends of coinfection risk by mapping the posterior marginal from the best fit model.

Results

Of the total 608,312 TB case notifications, 194,129 were HIV co-infected. The proportion of TB-HIV co-infection was higher in females (39.7%) than in males (27.0%). A significant share of the co-infection was among adults aged 35 to 44 years (46.7%) and 45 to 54 years (42.1%). Based on the Bayesian Defiance Information (DIC) and the effective number of parameters (pD) comparisons, the spatiotemporal model allowing space-time interaction was the best in explaining the geographical variations in TB-HIV coinfection. The model results suggested that the risk of TB-HIV coinfection was influenced by infrastructure index (Relative risk (RR) = 5.75, Credible Interval (Cr.I) = (1.65, 19.89)) and gender ratio (RR = 5.81e⁻⁰⁴, Cr. I = (1.06e⁻⁰⁴, 3.18e⁻⁰³). The lowest and highest temporal relative risks were in the years 2016 at 0.9 and 2012 at 1.07 respectively. The spatial pattern presented an increased co-infection risk in a number of counties. For the spatiotemporal interaction, only a few counties had a relative risk greater than 1 that varied in different years.

Conclusions

We identified elevated risk areas for TB/HIV co-infection and fluctuating temporal trends which could be because of improved TB case detection or surveillance bias caused by spatial heterogeneity in the co-infection dynamics. Focused interventions and continuous TB-HIV surveillance will ensure adequate resource allocation and significant reduction of HIV burden amongst TB patients.

The use of immunotherapy for the treatment of tuberculosis

INTRODUCTION

Tuberculosis (TB) is the first cause of mortality by a single infectious agent in the world, causing more than one million deaths worldwide as reported by the World Health Organization (WHO). For the optimal control of TB infection, a protective immune response that limits bacterial spread without causing damage to the host is essential. Although most healthy individuals are capable of generating protective responses, patients who suffer pulmonary TB commonly present a defective immune function. Areas covered: We intend to highlight the potential of novel immunotherapeutic strategies that enhance and promote effective immune responses. The following methodology was undertaken for establishing a literature search: the authors used PubMed to search for 'Pulmonary Tuberculosis' and keywords that denoted the novel immunotherapeutic strategies discussed in length in the text including antibodies, antimicrobial peptides, cell therapy, cytokines and gene therapy. Expert commentary: The current therapeutic regimens for this disease are complex and involve the prolonged use of multiple antibiotics with diverse side effects that lead to therapeutic failure and bacterial resistance. The standard appliance of immunotherapy and its deployment to vulnerable populations will require coordinated work and may serve as a powerful tool to combat the ensuing threat of TB.

Spanish Compliance With Guidelines for Prescribing Four Drugs in the Intensive Phase of Standard Tuberculosis Treatment

INTRODUCTION

International and Spanish guidelines recommend a 4-drug regimen in the intensive treatment of tuberculosis (TB). The aim of our study was to determine if these recommendations are followed in Spain, and the factors associated with the use of 3 drugs (standard regimen without ethambutol).

METHODOLOGY

Observational, multicenter, retrospective analysis of data from patients diagnosed with TB in practically all Spanish Autonomous Communities between 2007 and 2102. Factors associated with the use of 3 drugs were analyzed using logistic regression, and odds ratios (OR) and corresponding 95% confidence intervals (CI) were calculated.

RESULTS

A total of 3,189 patients were included, 1,413 (44.3%) of whom received 3 drugs. The percentage of 3-drug users among patients with positive sputum smear was 41.2%; among patients with resistance to at least 1 drug, 36.1%; among HIV-infected patients, 31.4%; and among immigrants, 24.8%. Factors associated with the use of 3 drugs were: female sex (OR=1.18; CI: 1.00-1.39); native Spanish (OR=3.09; CI: 2.58-3.70); retired (OR=1.42; CI: 1.14-1.77); homeless (OR=3.10; CI: 1.52-6.43); living alone (OR=1.62; CI: 1.11-2.36); living in a family (OR=1.97; CI: 1.48-2.65); seen by specialists in the region (OR=1.37; CI: 1.10;1.70); no HIV infection (OR=1.63; CI: 1.09-2.48); and negative sputum smear with positive culture (OR=1.59; CI: 1.25-2.02).

CONCLUSIONS

A large proportion of TB patients receive intensive treatment with 3 drugs. TB treatment recommendations should be followed, both in routine clinical practice and by the National Plan for Prevention and Control of Tuberculosis in Spain.

Risk Factors Associated with the Development of Tuberculosis Among HIV-Infected Patients in Khartoum in 2010

Background

Tuberculosis (TB) screening among patients infected with Human Immunodeficiency Virus (HIV) is one of the approaches for controlling TB-HIV co-infection. The absence of typical TB symptoms among HIV-infected patients makes diagnosis challenging. Identifying predisposing risk factors of TB among HIV-infected patients could possibly guide TB diagnosis and treatment. This study was designed to identify some important factors associated with TB among HIV-infected patients and to quantify the strength of this association.

Methodology

In 2010, a case control study was conducted in Khartoum State, Sudan. Cases and controls were selected by simple random sampling with a 1:2 ratio; 97 cases and 194 controls were enrolled in the study. A logistic regression model was built to estimate and quantify the strength of the association between the study variables and the outcome; a p-value less than 0.05 was considered the cut-off point for a significant statistical association.

Results

Past history of TB, CD4 count < 200 cells/µl, late clinical stages, non-employment, and no formal education were found to be risk factors for developing TB among HIV-infected patients. The adjusted ORs and 95% CIs were (6.9: 3.75–12.99), (4.8: 1.57–15.26), (5.8: 1.88-17.96), (2.5: 1.26–5.03), and (2.5: 1.28–4.63), respectively. Poor adherence, marital status, age, and gender are not associated with developing TB among HIV patients.

Conclusion

HIV patients who have at least one of the risk factors found in this analysis are at higher risk of TB; therefore, they should be screened more frequently and treated promptly, especially HIV patients with previous TB.

Promoting operational research through fellowships: a case study from the South-East Asia Union Office

In 2009, the International Union Against Tuberculosis and Lung Disease (The Union) and Médecins Sans Frontières (MSF) jointly developed a new paradigm for operational research (OR) capacity building and started a new process of appointing and supporting OR fellows in the field. This case study describes 1) the appointment of two OR fellows in The Union South-East Asia Office (USEA), New Delhi, India; 2) how this led to the development of an OR unit in that organisation; 3) achievements over the 5-year period from June 2009 to June 2014; and 4) challenges and lessons learnt. In June 2009, the first OR fellow in India was appointed on a full-time basis and the second was appointed in February 2012-both had limited previous experience in OR. From 2009 to 2014, annual research output and capacity building initiatives rose exponentially, and included 1) facilitation at 61 OR training courses/modules; 2) publication of 96 papers, several of which had a lasting impact on national policy and practice; 3) providing technical assistance in promoting OR; 4) building the capacity of medical college professionals in data management; 5) support to programme staff for disseminating their research findings; 6) reviewing 28 scientific papers for national or international peer-reviewed journals; and 7) developing 45 scientific abstracts for presentation at national and international conferences. The reasons for this success are highlighted along with ongoing challenges. This experience from India provides good evidence for promoting similar models elsewhere.

Directly-observed intermittent therapy versus unsupervised daily regimen during the intensive phase of antituberculosis therapy in HIV infected patients

The World Health Organization strongly recommends using daily antituberculosis therapy (ATT) during the intensive phase for HIV infected patients. India has the highest burden of tuberculosis in the world, but HIV infected patients are still receiving intermittent ATT. In this study we compared the mortality in patients who received directly-observed intermittent ATT versus self-administered daily ATT with fixed dose combinations during the intensive phase in a context of freely available antiretroviral therapy. The study included 1460 patients, 343 in the intermittent ATT group and 1117 in the daily ATT group. Baseline covariates of the two groups were balanced using inverse probability of treatment weighting based on propensity score methods. In a sensitivity analysis, continuous variables (albumin, CD4 count, and age) were modelled using restricted cubic smoothing splines. Compared with patients who received daily ATT, patients who received intermittent ATT had a 40% higher risk of mortality (1.4 hazard ratio; 95% confidence interval, 1.14-1.7). We estimated that the use of daily ATT could achieve a 10% absolute reduction in mortality at 12 months. Self-administered daily ATT was not associated with an increased risk of default from treatment. These results support the immediate implementation of daily ATT for HIV infected patients during the intensive phase in India.