Treatment efficacy of drug-resistant tuberculosis in Bashkortostan, Russia: A retrospective cohort study

Factors associated with tuberculosis drug resistance among presumptive multidrug resistance tuberculosis patients identified in a DRTB surveillance study in western Kenya

Multidrug-resistant tuberculosis (MDR-TB) is caused by M. tuberculosis (Mtb) with resistance to the first-line anti-TB medicines isoniazid (INH) and rifampicin (RIF). In Western Kenya, there is reported low prevalence of drug resistant strains among HIV tuberculosis patients, creating a need to determine factors associated with drug resistance patterns among presumptive MDR-TB patients. To determine factors associated with drug resistance patterns among presumptive MDR-TB patients in western Kenya. Three hundred and ninety (3 9 0) sputum sample isolates from among presumptive multidrug TB patients, were analyzed for TB drug resistance as per Ministry of Health (MoH) TB program diagnostic algorithm. Frequency and percentages were used to summarize categorical data while median and interquartile range (IQR) were used for continuous data. Multivariable logistic regression was carried out to identify factors associated with TB drug resistance. Out of 390 participants enrolled, 302/390 (77.4 %) were males, with a median age of 34 years. The HIV-infected were 118/390 (30.3 %). Samples included 322 (82.6 %) from presumptive patients, while 68/390 (17.4 %) were either lost to follow-up patients, failures to first-line treatment or newly diagnosed cases. A total of 64/390 (16.4 %) of the isolates had at least some form of drug resistance. Out of 390, 14/390 (3.6 %) had MDR, 12 (3.1 %) were RIF mono-resistance, 34 (8.7 %) had INH, while 4 (1 %) had ethambutol resistance. The category of previously treated patients (those who received or are currently on TB treatment) had a 70 % reduced likelihood of resistance (aOR: 0.30; 95 % CI: 0.13-0.70). In contrast, older age was associated with an increased likelihood of resistance to INH and RIF, with an adjusted odds ratio of 1.04 per year (95 % CI: 1.00-1.08). Prompt MDR-TB diagnosis is essential for appropriate patient care, management, and disease prevention and control. We recommend active surveillance on drug resistant TB in these regions to detect drug resistance patterns for rapid disease management.

Why do patients with DR-TB do not complete their treatment? Findings of a qualitative study from Pakistan

BACKGROUND

One of the major reasons for unsuccessful treatment outcomes among patients with drug-resistant tuberculosis (DR-TB) is the high rate of loss to follow-up (LTFU). However, in Pakistan, no qualitative study has been conducted to explore the perceptions of LTFU patients with regard to DR-TB treatment, the problems they face and the reasons for LTFU in detail.

METHODS

This was a qualitative study that involved semistructured, indepth, face-to-face interviews of 39 LTFU patients with DR-TB. All interviews were carried out in Pakistan's national language 'Urdu' using an interview guide in two phases: the first phase was from December 2020 to February 2021 among patients with extensively drug-resistant tuberculosis and the second phase from July 2021 to September 2021 among patients with multidrug-resistant tuberculosis.

RESULTS

The inductive thematic analysis of audio-recorded interviews generated the following four key themes, which were the major reasons reported by the participants of the current study to have led to LTFU: (1) patient-related factors, such as lack of awareness about the total duration of DR-TB treatment, fatigue from previous multiple failed episodes, lack of belief in treatment efficacy and perception of DR-TB as a non-curable disease; (2) medication-related factors, such as use of injectables, high pill burden, longer duration and adverse events; (3) socioeconomic factors, such as gender discrimination, poor socioeconomic conditions, non-supportive family members, social isolation and unemployment; and (4) service provider-related factors, such as distant treatment centres, non-availability of a qualified person, lack of adequate counselling and poor attitude of healthcare professionals.

CONCLUSION

In the current study, patients' perceptions about DR-TB treatment, socioeconomic condition, medication and service provider-related factors emerged as barriers to the successful completion of DR-TB treatment. Increasing patients' awareness about the duration of DR-TB treatment, interacting sessions with successfully treated patients, availability of rapid drug susceptibility testing facilities at treatment centres, decentralising treatment and using the recently recommended all-oral regimen may further decrease the rate of LTFU.

Global treatment outcomes of extensively drug-resistant tuberculosis in adults: A systematic review and meta-analysis

INTRODUCTION

Historically, extensively drug-resistant tuberculosis has been notoriously difficult to treat with devasting outcomes. As we are coming to the end of an era where the 2006 extensively drug-resistant tuberculosis definitions and old treatment regimens are being replaced, we aimed to estimate the proportion of extensively drug-resistant tuberculosis patients globally who achieved successful treatment outcomes.

METHODS

We conducted a systematic review of PubMed/MEDLINE, Scopus, Web of Science, and Embase from January 1, 2005, through April 3, 2023. Included studies reported WHO treatment outcomes, or adaptions hereof, for pre-extensively and/or extensively drug-resistant tuberculosis patients according to the 2006 WHO definition. Eligible studies included cohorts of at least 10 adults (aged>18 years) that were not pregnant. Using a random-effects model, we calculated pooled proportions of treatment outcomes and performed sensitivity and subgroup analyses. PROSPERO registration number: CRD42022340961.

RESULTS

Among 5056 studies reviewed, we identified 94 studies from 26 countries, involving 10,223 extensively drug-resistant tuberculosis patients. The pooled proportion of successful treatment outcomes was 44.2% (95%CI: 38.3-50.3). Sensitivity analyses consistently produced similar estimates. A slight improvement in treatment outcomes was observed after 2013. Furthermore, 25 studies reported outcomes for 3564 individuals with pre-extensively drug-resistant tuberculosis, of which 63.3% achieved successful treatment (95%CI: 43.1-72.5).

CONCLUSION

Globally, the success rate of extensively drug-resistant tuberculosis treatment is 44.2%, far below the WHO's target rate of 75%. These results may serve as a reference for future studies assessing extensively drug-resistant tuberculosis treatment outcomes under the 2021 definition treated with better treatment regimens available. Comprehensive surveillance data of extensively drug-resistant tuberculosis outcomes from the whole world are desirable to monitor treatment progress.

Gender differences among patients with drug resistant tuberculosis and HIV co-infection in Uganda: a countrywide retrospective cohort study

BACKGROUND

Gender differences among patients with drug resistant tuberculosis (DRTB) and HIV co-infection could affect treatment outcomes. We compared characteristics and treatment outcomes of DRTB/HIV co-infected men and women in Uganda.

METHODS

We conducted a retrospective chart review of patients with DRTB from 16 treatment sites in Uganda. Eligible patients were aged ≥ 18 years, had confirmed DRTB, HIV co-infection and a treatment outcome registered between 2013 and 2019. We compared socio-demographic and clinical characteristics and tuberculosis treatment outcomes between men and women. Potential predictors of mortality were determined by cox proportional hazard regression analysis that controlled for gender. Statistical significance was set at p < 0.05.

RESULTS

Of 666 DRTB/HIV co-infected patients, 401 (60.2%) were men. The median (IQR) age of men and women was 37.0 (13.0) and 34.0 (13.0) years respectively (p < 0.001). Men were significantly more likely to be on tenofovir-based antiretroviral therapy (ART), high-dose isoniazid-containing DRTB regimen and to have history of cigarette or alcohol use. They were also more likely to have multi-drug resistant TB, isoniazid and streptomycin resistance and had higher creatinine, aspartate and gamma-glutamyl aminotransferase and total bilirubin levels. Conversely, women were more likely to be unemployed, unmarried, receive treatment from the national referral hospital and to have anemia, a capreomycin-containing DRTB regimen and zidovudine-based ART. Treatment success was observed among 437 (65.6%) and did not differ between the genders. However, mortality was higher among men than women (25.7% vs. 18.5%, p = 0.030) and men had a shorter mean (standard error) survival time (16.8 (0.42) vs. 19.0 (0.46) months), Log Rank test (p = 0.046). Predictors of mortality, after adjusting for gender, were cigarette smoking (aHR = 4.87, 95% CI 1.28-18.58, p = 0.020), an increase in alanine aminotransferase levels (aHR = 1.05, 95% CI 1.02-1.07, p < 0.001), and history of ART default (aHR = 3.86, 95% CI 1.31-11.37, p = 0.014) while a higher baseline CD4 count was associated with lower mortality (aHR = 0.94, 95% CI 0.89-0.99, p = 0.013 for every 10 cells/mm³ increment).

CONCLUSION

Mortality was higher among men than women with DRTB/HIV co-infection which could be explained by several sociodemographic and clinical differences.

Treatment Outcomes of Extensively Drug-Resistant Tuberculosis in Pakistan: A Countrywide Retrospective Record Review

Background: The current study is conducted with the aim to the fill the gap of information regarding treatment outcomes and variables associated with unsuccessful outcome among XDR-TB patients from Pakistan. Methods: A total of 404 culture confirmed XDR-TB patients who received treatment between 1^st May 2010 and June 30, 2017 at 27 treatment centers all over Pakistan were retrospectively followed until their treatment outcomes were reported. A p-value <0.05 reflected a statistical significant association. Results: The patients had a mean age 32.9 ± 14.1 years. The overall treatment success rate was 40.6% (95% confidence interval [CI]:35.80-45.60%). A total of 155 (38.4%) patients were declared cured, 9 (2.2%) completed treatment, 149 (36.9%) died, 60 (14.9%) failed treatment and 31 (7.7%) were lost to follow up (LTFU). The results of the multivariate binary logistic regression analysis revealed that the patients' age of >60 years (OR = 4.69, 95%CI:1.57-15.57) and receiving high dose isoniazid (OR = 2.36, 95%CI:1.14-4.85) had statistically significant positive association with death, whereas baseline body weight >40 kg (OR = 0.43, 95%CI:0.25-0.73) and sputum culture conversion in the initial two months of treatment (OR = 0.33, 95%CI:0.19-0.58) had statistically significant negative association with death. Moreover, male gender had statistically significant positive association (OR = 1.92, 95%CI:1.04-3.54) with LTFU. Conclusion: The treatment success rate (40.6%) of XDR-TB patients in Pakistan was poor. Providing special attention and enhanced clinical management to patients with identified risk factors for death and LTFU in the current cohort may improve the treatment outcomes.

Biomarkers of treatment success in fully sensitive pulmonary tuberculosis patients: a multicenter longitudinal study

Aim: Novel biomarkers that are able to accurately monitor tuberculosis (TB) treatment effectiveness are needed to adjust therapy and identify a need for a regimen change. Materials & methods: In our study, conducted on a cohort comprising 100 pulmonary TB patients, we analyzed the role of plasma cytokines and Toll-like receptors expression as biomarkers of treatment response. Results: Changes in toll-interacting protein (TOLLIP) and lymphocyte antigen 96 (LY96) gene expression as well as nine cytokine levels over the first 2 months were significantly associated with successful treatment outcome. Successful treatment was associated with higher serum concentration of Toll-like receptor-2. Conclusion: Our results suggest that differential expression of specific effector molecules and dynamics of selected cytokines may help to identify those responding to TB treatment early.

Unfavorable outcomes to second-line tuberculosis therapy among HIV-infected versus HIV-uninfected patients in sub-Saharan Africa: A systematic review and meta-analysis

BACKGROUND

Drug resistance is a key obstacle to the global target set to end tuberculosis by 2030. Clinical complexities in drug-resistant tuberculosis and HIV-infection co-management could worsen outcomes of second-line anti-tuberculosis drugs. A comprehensive estimate for risks of unsuccessful outcomes to second-line tuberculosis therapy in HIV-infected versus HIV-uninfected patients is mandatory to address such aspects in segments of the target set. Therefore, this meta-analysis was aimed to estimate the pooled risk ratios of unfavorable outcomes to second-line tuberculosis therapy between HIV-infected and HIV-uninfected patients in sub-Saharan Africa.

METHODS

We conducted a literature search from PubMed/MEDLINE, EMBASE, SCOPUS and Google Scholar. We screened the retrieved records by titles and abstracts. Finally, we assessed eligibility and quality of full-text articles for the records retained by employing appraisal checklist of the Joanna Briggs Institute. We analyzed the data extracted from the included studies by using Review Manager Software, version 5.3 and presented our findings in forest and funnel plots. Protocol for this study was registered on PROSPERO (ID: CRD42020160473).

RESULTS

A total of 19 studies with 1,766 from 4,481 HIV-infected and 1,164 from 3,820 HIV-uninfected patients had unfavorable outcomes. The risk ratios we estimated between HIV-infected and HIV-uninfected drug-resistant tuberculosis patients were 1.18 (95% CI: 1.07-1.30; I2 = 48%; P = 0.01) for the overall unfavorable outcome; 1.50 (95% CI: 1.30-1.74) for death; 0.66 (95% CI: 0.38-1.13) for treatment failure; and 0.82 (95% CI: 0.74-0.92) for loss from treatment. Variable increased risks of unfavorable outcomes estimated for subgroups with significance in mixed-age patients (RR: 1.22; 95% CI: 1.10-1.36) and eastern region of sub-Saharan Africa (RR: 1.47; 95% CI: 1.23-1.75).

CONCLUSIONS

We found a higher risk of unfavorable treatment outcome in drug-resistant tuberculosis patients with death highly worsening in HIV-infected than in those HIV-uninfected patients. The risks for the unfavorable outcomes were significantly higher in mixed-age patients and in the eastern region of sub-Saharan Africa. Therefore, special strategies that reduce the risks of death should be discovered and implemented for HIV and drug-resistant tuberculosis co-infected patients on second-line tuberculosis therapy with optimal integration of the two programs in the eastern region of sub-Saharan Africa.

Factors associated with mortality from tuberculosis in Iran: an application of a generalized estimating equation-based zero-inflated negative binomial model to national registry data

OBJECTIVES

Tuberculosis (TB) is a global public health problem that causes morbidity and mortality in millions of people per year. The purpose of this study was to examine the relationship of potential risk factors with TB mortality in Iran.

METHODS

This cross-sectional study was performed on 9,151 patients with TB from March 2017 to March 2018 in Iran. Data were gathered from all 429 counties of Iran by the Ministry of Health and Medical Education and Statistical Center of Iran. In this study, a generalized estimating equation-based zero-inflated negative binomial model was used to determine the effect of related factors on TB mortality at the community level. For data analysis, R version 3.4.2 was used with the relevant packages.

RESULTS

The risk of mortality from TB was found to increase with the unemployment rate (β^=0.02), illiteracy (β^=0.04), household density per residential unit (β^=1.29), distance between the center of the county and the provincial capital (β^=0.03), and urbanization (β^=0.81). The following other risk factors for TB mortality were identified: diabetes (β^=0.02), human immunodeficiency virus infection (β^=0.04), infection with TB in the most recent 2 years (β^=0.07), injection drug use (β^=0.07), long-term corticosteroid use (β^=0.09), malignant diseases (β^=0.09), chronic kidney disease (β^=0.32), gastrectomy (β^=0.50), chronic malnutrition (β^=0.38), and a body mass index more than 10% under the ideal weight (β^=0.01). However, silicosis had no effect.

CONCLUSIONS

The results of this study provide useful information on risk factors for mortality from TB.