Survival from XDR-TB is associated with modifiable clinical characteristics in rural South Africa

Predictors of mortality in patients with drug-resistant tuberculosis: A systematic review and meta-analysis

BACKGROUND

Even though the lives of millions have been saved in the past decades, the mortality rate in patients with drug-resistant tuberculosis is still high. Different factors are associated with this mortality. However, there is no comprehensive global report addressing these risk factors. This study aimed to determine the predictors of mortality using data generated at the global level.

METHODS

We systematically searched five electronic major databases (PubMed/Medline, CINAHL, EMBASE, Scopus, Web of Science), and other sources (Google Scholar, Google). We used the Joanna Briggs Institute Critical Appraisal tools to assess the quality of included articles. Heterogeneity assessment was conducted using the forest plot and I2 heterogeneity test. Data were analyzed using STATA Version 15. The pooled hazard ratio, risk ratio, and odd's ratio were estimated along with their 95% CIs.

RESULT

After reviewing 640 articles, 49 studies met the inclusion criteria and were included in the final analysis. The predictors of mortality were; being male (HR = 1.25,95%CI;1.08,1.41,I2;30.5%), older age (HR = 2.13, 95%CI;1.64,2.62,I2;59.0%,RR = 1.40,95%CI; 1.26, 1.53, I2; 48.4%) including a 1 year increase in age (HR = 1.01, 95%CI;1.00,1.03,I2;73.0%), undernutrition (HR = 1.62,95%CI;1.28,1.97,I2;87.2%, RR = 3.13, 95% CI; 2.17,4.09, I2;0.0%), presence of any type of co-morbidity (HR = 1.92,95%CI;1.50-2.33,I2;61.4%, RR = 1.61, 95%CI;1.29, 1.93,I2;0.0%), having diabetes (HR = 1.74, 95%CI; 1.24,2.24, I2;37.3%, RR = 1.60, 95%CI;1.13,2.07, I2;0.0%), HIV co-infection (HR = 2.15, 95%CI;1.69,2.61, I2; 48.2%, RR = 1.49, 95%CI;1.27,1.72, I2;19.5%), TB history (HR = 1.30,95%CI;1.06,1.54, I2;64.6%), previous second-line anti-TB treatment (HR = 2.52, 95% CI;2.15,2.88, I2;0.0%), being smear positive at the baseline (HR = 1.45, 95%CI;1.14,1.76, I2;49.2%, RR = 1.58,95%CI;1.46,1.69, I2;48.7%), having XDR-TB (HR = 2.01, 95%CI;1.50,2.52, I2;60.8%, RR = 2.44, 95%CI;2.16,2.73,I2;46.1%), and any type of clinical complication (HR = 2.98, 95%CI; 2.32, 3.64, I2; 69.9%). There are differences and overlaps of predictors of mortality across different drug-resistance categories. The common predictors of mortality among different drug-resistance categories include; older age, presence of any type of co-morbidity, and undernutrition.

CONCLUSION

Different patient-related demographic (male sex, older age), and clinical factors (undernutrition, HIV co-infection, co-morbidity, diabetes, clinical complications, TB history, previous second-line anti-TB treatment, smear-positive TB, and XDR-TB) were the predictors of mortality in patients with drug-resistant tuberculosis. The findings would be an important input to the global community to take important measures.

Survival model analysis of tuberculosis treatment among patients with human immunodeficiency virus coinfection

Background

Tuberculosis (TB) with human immunodeficiency virus (HIV) coinfection is the highest clinical epidemiology and public health issue. Despite many programs established to tackle the epidemic, TB target controls have not been reached. One of the many factors attributed to the failure in TB treatment is HIV coinfection. The aim of this study is to assess the survival rate of HIV infection among TB patients and the risk factors of death among the TB patients with HIV coinfection during the retro of directly observed treatment, short-course (DOTS) program.

Methods

This study is a retrospective cohort conducted to compare the survivorship between TB/HIV patients for 8 months DOTS. Death among TB patients was considered as failures and those defaulted or survived were censored. The Cox proportional-hazards regression and log-linear model were used to establish the hazard ratio (HR) of death for each variable at baseline and estimate the risk factors effect among TB patients.

Results

The findings revealed that 50% of death from TB/HIV patients were from HIV coinfection (advanced HR = 2.01, 95% confidence interval = 1.13-3.17). The risk of death was significantly higher in HIV-positive TB patients (P = 0.000) during the extension care phase. TB/HIV-positive patients on antiretroviral therapy have decreased survival rate (log-rank test = 14.88, df = 2, P = 0.0001). The probability of TB patients surviving is significantly decreased in HIV positive with some factors such as age, weight, smoking, and alcohol found significant.

Conclusion

The probability of survival in HIV-positive TB patients was significantly lower during the TB treatment. Weight loss, age, alcohol, smoking, and pregnancy were showed to affect the survival probability of TB/HIV patients' coinfection significantly.

Trends in C-Reactive Protein, D-Dimer, and Fibrinogen during Therapy for HIV-Associated Multidrug-Resistant Tuberculosis

HIV-positive adults on treatment for multi drug-resistant tuberculosis (MDR-TB) experience high mortality. Biomarkers of HIV/MDR-TB treatment response may enable earlier treatment modifications that improve outcomes. To determine whether changes in C-reactive protein (CRP), D-dimer, and fibrinogen were associated with treatment outcome among those with HIV/MDR-TB coinfection, we studied 20 HIV-positive participants for the first 16 weeks of MDR-TB therapy. Serum CRP, fibrinogen, and D-dimer were measured at baseline and serially while on treatment. At baseline, all biomarkers were elevated above normal levels, with median CRP 86.15 mg/L (interquartile range [IQR] 29.25-149.32), D-dimer 0.85 µg/mL (IQR 0.34-1.80), and fibrinogen 4.11 g/L (IQR 3.75-6.31). C-reactive protein decreased significantly within 10 days of treatment initiation and fibrinogen within 28 days; D-dimer did not change significantly. Five (25%) participants died after a median of 32 days. Older age (median age of 38y among survivors and 54y among deceased, P = 0.008) and higher baseline fibrinogen (3.86 g/L among survivors and 6.37 g/L among deceased, P = 0.02) were significantly associated with death. After adjusting for other measured variables, higher CRP concentrations at the beginning of each measurement interval were significantly associated with a higher risk of death during that interval. Trends in fibrinogen and CRP may be useful for evaluating early response to treatment among individuals with HIV/MDR-TB coinfection.

Low expression Macrophage Migration Inhibitory Factor (MIF) alleles and tuberculosis in HIV infected South Africans

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Low expression MIF alleles are prevalent in South Africa, which has the greatest burden of TB and HIV.

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Low genotypic MIF expressers were more frequent among HIV cases with TB compared to those without TB.

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Serum MIF correlated with lower CD4 cells regardless of TB, suggesting HIV impacts MIF expression.

Host immunity is crucial for controlling M. tuberculosis infection. Functional polymorphisms in the cytokine macrophage migration inhibitory factor (MIF) show global population stratification, with the highest prevalence of low expression MIF alleles found in sub-Saharan Africans, which is a population with the greatest confluence of both TB and HIV infection and disease. We investigated the association between MIF alleles and tuberculosis (TB) and HIV in South Africa. We acquired clinical information and determined the frequency of two MIF promoter variants: a functional −794 CATT_5-8 microsatellite and an associated −173 G/C SNP in two HIV-positive cohorts of patients with active laboratory-confirmed TB and in controls without active TB who were all HIV positive. We found a greater frequency of low expression MIF promoter variants (-794 CATT_5,6) among TB disease cases compared to controls (OR = 2.03, p = 0.023), supporting a contribution of genetic low MIF expression to the high prevalence of TB in South Africa. Among those with HIV, circulating MIF levels also were associated with lower CD4 cell counts irrespective of TB status (p = 0.016), suggesting an influence of HIV immunosuppression on MIF expression.

Mortality and associated factors of patients with extensive drug-resistant tuberculosis: an emerging public health crisis in China

Background

Limited treatment options of extensive drug-resistant tuberculosis (XDR-TB) have led to its high mortality worldwide. Relevant data about mortality of XDR-TB patients in literature are limited and likely underestimate the real situation in China, since the majority of patients with XDR-TB are lost to follow-up after discharge from TB hospitals. In this study, we sought to investigate the mortality and associated risk factors of Human Immunodeficiency Virus (HIV)-negative patients with XDR-TB in China.

Methods

All patients who were diagnosed with XDR-TB for the first time in four TB care centers across China between March 2013 and February 2015 were consecutively enrolled. Active tracking through contacting patients or family members by phone or home visit was conducted to obtain patients’ survival information by February 2017. Multivariable Cox regression models were used to evaluate factors associated with mortality.

Results

Among 67 patients enrolled, the mean age was 48.7 (Standard Deviation [SD] = 16.7) years, and 51 (76%) were men. Fourteen patients (21%) were treatment naïve at diagnosis indicating primary transmission. 58 (86.8%) patients remained positive for sputum smear or culture when discharged. During a median follow-up period of 32 months, 20 deaths occurred, with an overall mortality of 128 per 1000 person-years. Among patients who were dead, the median survival was 5.4 months (interquartile range [IQR]: 2.2–17.8). Seventeen (85%) of them died at home, among whom the median interval from discharge to death was 8.4 months (IQR: 2.0–18.2). In Cox proportional hazards regression models, body mass index (BMI) < 18.5 kg/m² (adjusted hazard ratio [aHR] = 4.5, 95% confidence interval [CI]: 1.3–15.7), smoking (aHR = 4.7, 95%CI:1.7–13.2), or a clinically significant comorbidity including heart, lung, liver, or renal disorders or auto-immune diseases (aHR = 3.5, 95%CI: 1.3–9.4), were factors independently associated with increased mortality.

Conclusion

Our study suggested an alarming situation of XDR-TB patients in China with a sizable proportion of newly transmitted cases, a high mortality rate, and a long period in community. This observation calls for urgent actions to improve XDR-TB case management in China, including providing regimens with high chances of cure and palliative care, and enhanced infection control measures.

Time to treatment for rifampicin-resistant tuberculosis: systematic review and meta-analysis

BACKGROUND

To reduce transmission and improve patient outcomes, rapid diagnosis and treatment of rifampicin-resistant tuberculosis (RR-TB) is required.

OBJECTIVE

To conduct a systematic review and meta-analysis assessing time to treatment for RR-TB and variability using diagnostic testing methods and treatment delivery approach.

DESIGN

Studies from 2000 to 2015 reporting time to second-line treatment initiation were selected from PubMed and published conference abstracts.

RESULTS

From 53 studies, 83 cohorts (13 034 patients) were included. Overall weighted mean time to treatment from specimen collection was 81 days (95%CI 70-91), and was shorter with ambulatory (57 days, 95%CI 40-74) than hospital-based treatment (86 days, 95%CI 71-102). Time to treatment was shorter with genotypic susceptibility testing (38 days, 95%CI 27-49) than phenotypic testing (108 days, 95%CI 98-117). The mean percentage of diagnosed patients initiating treatment was 76% (95%CI 70-83, range 25-100).

CONCLUSION

Time to second-line anti-tuberculosis treatment initiation is extremely variable across studies, and often unnecessarily long. Reduced delays are associated with genotypic testing and ambulatory treatment settings. Routine monitoring of the proportion of diagnosed patients initiating treatment and time to treatment are necessary to identify areas for intervention.

Integrated Tuberculosis/Human Immunodeficiency Virus Community-Based Case Finding in Rural South Africa: Implications for Tuberculosis Control Efforts

Background

Intensive case finding is endorsed for tuberculosis (TB) control in high-risk populations. Novel case-finding strategies are needed in hard-to-reach rural populations with high prevalence of TB and human immunodeficiency virus (HIV).

Methods

We performed community-based integrated HIV and TB intensive case finding in a rural South African subdistrict from March 2010 to June 2012. We offered TB symptom screening, sputum collection for microbiologic diagnosis, rapid fingerstick HIV testing, and phlebotomy for CD4 cell count. We recorded number of cases detected and calculated population-level rates and number needed to screen (NNS) for drug-susceptible and -resistant TB.

Results

Among 5615 persons screened for TB at 322 community sites, 91.2% accepted concurrent HIV testing, identifying 510 (9.9%) HIV-positive individuals with median CD4 count of 382 cells/mm³ (interquartile range = 260–552). Tuberculosis symptoms were reported by 2049 (36.4%), and sputum was provided by 1033 (18.4%). Forty-one (4.0%) cases of microbiologically confirmed TB were detected for an overall case notification rate of 730/100000 (NNS = 137); 11 (28.6%) were multidrug-resistant or extensively drug-resistant TB. Only 5 (12.2%) TB cases were HIV positive compared with an HIV coinfection rate of 64% among contemporaneously registered TB cases (P = .001).

Conclusion

Community-based integrated intensive case finding is feasible and is high yield for drug-susceptible and -resistant TB and HIV in rural South Africa. Human immunodeficiency virus–negative tuberculosis predominated in this community sample, suggesting a distinct TB epidemiology compared with cases diagnosed in healthcare facilities. Increasing HIV/TB integrated community-based efforts and other strategies directed at both HIV-positive and HIV-negative tuberculosis may contribute to TB elimination in high TB/HIV burden regions.

Extended-release naltrexone reduces alcohol consumption among released prisoners with HIV disease as they transition to the community

BACKGROUND

Alcohol use disorders (AUDs) are highly prevalent among persons living with HIV (PLH) within the criminal justice system (CJS). Extended-release naltrexone (XR-NTX) has not been previously evaluated among CJS-involved PLH with AUDs.

METHODS

A randomized, double-blind, placebo-controlled trial was conducted among 100 HIV+ prisoners with AUDs. Participants were randomized 2:1 to receive 6 monthly injections of XR-NTX or placebo starting one week prior to release. Using multiple imputation strategies for data missing completely at random, data were analyzed for the 6-month post-incarceration period. Main outcomes included: time to first heavy drinking day; number of standardized drinks/drinking day; percent of heavy drinking days; pre- to post-incarceration change in average drinks/day; total number of drinking days; and a composite alcohol improvement score comprised of all 5 parameters.

RESULTS

There was no statistically significant difference overall between treatment arms for time-to-heavy-drinking day. However, participants aged 20-29 years who received XR-NTX had a longer time to first heavy drinking day compared to the placebo group (24.1 vs. 9.5days; p<0.001). There were no statistically significant differences between groups for other individual drinking outcomes. A sub-analysis, however, found participants who received ≥4 XR-NTX were more likely (p<0.005) to have improved composite alcohol scores than the placebo group. Post-hoc power analysis revealed that despite the study being powered for HIV outcomes, sufficient power (0.94) was available to distinguish the observed differences.

CONCLUSIONS

Among CJS-involved PLH with AUDs transitioning to the community, XR-NTX lengthens the time to heavy drinking day for younger persons; reduces alcohol consumption when using a composite alcohol consumption score; and is not associated with any serious adverse events.

Individualizing management of extensively drug-resistant tuberculosis: diagnostics, treatment, and biomarkers

INTRODUCTION

Success rates for treatment of extensively drug resistant tuberculosis (XDR-TB) are low due to limited treatment options, delayed diagnosis and inadequate health care infrastructure. Areas covered: This review analyses existing programmes of prevention, diagnosis and treatment of XDR-TB. Improved diagnostic procedures and rapid molecular tests help to select appropriate drugs and dosages. Drugs dosages can be further tailored to the specific conditions of the patient based on quantitative susceptibility testing of the M. tuberculosis isolate and use of therapeutic drug monitoring. Pharmacovigilance is important for preserving activity of the novel drugs bedaquiline and delamanid. Furthermore, biomarkers of treatment response must be developed and validated to guide therapeutic decisions. Expert commentary: Given the currently poor treatment outcomes and the association of XDR-TB with HIV in endemic regions, a more patient oriented approach regarding diagnostics, drug selection and tailoring and treatment evaluation will improve treatment outcome. The different areas of expertise should be covered by a multidisciplinary team and may involve the transition of patients from hospitalized to home or community-based treatment.

Integrating Community-Based Interventions to Reverse the Convergent TB/HIV Epidemics in Rural South Africa

The WHO recommends integrating interventions to address the devastating TB/HIV co-epidemics in South Africa, yet integration has been poorly implemented and TB/HIV control efforts need strengthening. Identifying infected individuals is particularly difficult in rural settings. We used mathematical modeling to predict the impact of community-based, integrated TB/HIV case finding and additional control strategies on South Africa’s TB/HIV epidemics. We developed a model incorporating TB and HIV transmission to evaluate the effectiveness of integrating TB and HIV interventions in rural South Africa over 10 years. We modeled the impact of a novel screening program that integrates case finding for TB and HIV in the community, comparing it to status quo and recommended TB/HIV control strategies, including GeneXpert, MDR-TB treatment decentralization, improved first-line TB treatment cure rate, isoniazid preventive therapy, and expanded ART. Combining recommended interventions averted 27% of expected TB cases (95% CI 18–40%) 18% HIV (95% CI 13–24%), 60% MDR-TB (95% CI 34–83%), 69% XDR-TB (95% CI 34–90%), and 16% TB/HIV deaths (95% CI 12–29). Supplementing these interventions with annual community-based TB/HIV case finding averted a further 17% of TB cases (44% total; 95% CI 31–56%), 5% HIV (23% total; 95% CI 17–29%), 8% MDR-TB (68% total; 95% CI 40–88%), 4% XDR-TB (73% total; 95% CI 38–91%), and 8% TB/HIV deaths (24% total; 95% CI 16–39%). In addition to increasing screening frequency, we found that improving TB symptom questionnaire sensitivity, second-line TB treatment delays, default before initiating TB treatment or ART, and second-line TB drug efficacy were significantly associated with even greater reductions in TB and HIV cases. TB/HIV epidemics in South Africa were most effectively curtailed by simultaneously implementing interventions that integrated community-based TB/HIV control strategies and targeted drug-resistant TB. Strengthening existing TB and HIV treatment programs is needed to further reduce disease incidence.

Improved survival in multidrug-resistant tuberculosis patients receiving integrated tuberculosis and antiretroviral treatment in the SAPiT Trial

BACKGROUND

The therapeutic effects of antiretroviral treatment (ART) in patients with multidrug-resistant tuberculosis (MDR-TB) and human immunodeficiency virus (HIV) infection have not been established.

OBJECTIVE

To assess therapeutic outcomes of integrating ART with treatment for MDR-TB.

DESIGN

A subgroup of MDR-TB patients from a randomised controlled trial, the SAPiT (Starting Antiretroviral Therapy at Three Points in Tuberculosis) study, conducted in an out-patient clinic in Durban, South Africa, from 2008 to 2012.

METHODS

Clinical outcomes at 18 months were compared in patients randomised to receive ART within 12 weeks of initiating standard first-line anti-tuberculosis treatment with those who commenced ART after completing anti-tuberculosis treatment.

RESULTS

Mycobacterium tuberculosis drug susceptibility results were available in 489 (76%) of 642 SAPiT patients: 23 had MDR-TB, 14 in the integrated treatment arm and 9 in the sequential treatment arm. At 18 months, the mortality rate was 11.9/100 person-years (py; 95%CI 1.4-42.8) in the combined integrated treatment arm and 56.0/100 py (95%CI 18.2-130.8) in the sequential treatment arm (hazard ratio adjusted for baseline CD4 count and whether MDR-TB treatment was initiated: 0.14; 95%CI 0.02-0.94, P = 0.04).

CONCLUSION

Despite the small sample size, the 86% reduction in mortality due to early initiation of ART in MDR-TB patients was statistically significant.

Prevalence of Extensively Drug Resistant Tuberculosis among Archived Multidrug Resistant Tuberculosis Isolates in Zimbabwe

We conducted a cross-sectional study of second line drug resistance patterns and genetic diversity of MDR-TB isolates archived at the BRTI-TB Laboratory, Harare, between January 2007 and December 2011. DSTs were performed for second line antituberculosis drugs. XDR-TB strains were defined as MDR-TB strains with resistance to either kanamycin and ofloxacin or capreomycin and ofloxacin. Strain types were identified by spoligotyping. No resistance to any second line drugs was shown in 73% of the isolates, with 23% resistant to one or two drugs but not meeting the definition of XDR-TB. A total of 26 shared types were identified, and 18 (69%) matched preexisting shared types in the current published spoligotype databases. Of the 11 out of 18 clustered SITs, 4 predominant (>6 isolates per shared type) were identified. The most and least abundant types were SIT 1468 (LAM 11-ZWE) with 12 (18%) isolates and SIT 53 (T1) with 6 (9%) isolates, respectively. XDR-TB strains are rare in Zimbabwe, but the high proportion of “pre-XDR-TB” strains and treatment failure cases is of concern. The genetic diversity of the MDR-TB strains showed no significant association between SITs and drug resistance.

Natural ventilation reduces high TB transmission risk in traditional homes in rural KwaZulu-Natal, South Africa

BACKGROUND

Transmission of drug susceptible and drug resistant TB occurs in health care facilities, and community and households settings, particularly in highly prevalent TB and HIV areas. There is a paucity of data regarding factors that may affect TB transmission risk in household settings. We evaluated air exchange and the impact of natural ventilation on estimated TB transmission risk in traditional Zulu homes in rural South Africa.

METHODS

We utilized a carbon dioxide decay technique to measure ventilation in air changes per hour (ACH). We evaluated predominant home types to determine factors affecting ACH and used the Wells-Riley equation to estimate TB transmission risk.

RESULTS

Two hundred eighteen ventilation measurements were taken in 24 traditional homes. All had low ventilation at baseline when windows were closed (mean ACH = 3, SD = 3.0), with estimated TB transmission risk of 55.4% over a ten hour period of exposure to an infectious TB patient. There was significant improvement with opening windows and door, reaching a mean ACH of 20 (SD = 13.1, p < 0.0001) resulting in significant decrease in estimated TB transmission risk to 9.6% (p < 0.0001). Multivariate analysis identified factors predicting ACH, including ventilation conditions (windows/doors open) and window to volume ratio. Expanding ventilation increased the odds of achieving ≥12 ACH by 60-fold.

CONCLUSIONS

There is high estimated risk of TB transmission in traditional homes of infectious TB patients in rural South Africa. Improving natural ventilation may decrease household TB transmission risk and, combined with other strategies, may enhance TB control efforts.