Outcomes of a nine-month regimen for rifampicin-resistant tuberculosis up to 24 months after treatment completion in nine African countries.

BACKGROUND: Treatment outcomes of the shorter regimen for rifampicin-resistant tuberculosis are not completely established. We report on these outcomes two years after treatment completion among patients enrolled in an observational cohort study in nine African countries. METHODS: 1,006 patients treated with the nine-month regimen were followed every six months with sputum cultures up to 24 months after treatment completion. The risk of any unfavourable outcome, of failure and relapse, and of death during and after treatment was analysed according to patient's characteristics and initial drug susceptibility by Cox proportional hazard models. FINDINGS: Respectively 67.8% and 57.2% patients had >=1 culture result six months and 12 months after treatment completion. Fourteen relapses were diagnosed. The probability of relapse-free success was 79.3% (95% confidence interval [CI] 76.6-82.0%) overall, 80.9% (95% CI 78.0-84.0%) among HIV-negative and 72.5% (95% CI 66.5-78.9%) among HIV-infected patients. Initial fluoroquinolone (adjusted hazard ratio [aHR] 6.7 [95% CI 3.4-13.1]) and isoniazid resistance (aHR 9.4 [95% CI 1.3-68.0]) were significantly associated with increased risk of failure/relapse and of any unfavourable outcome. INTERPRETATION: The close to 80% relapse-free success indicates the good outcome of the regimen in low-and middle-income settings. Results confirm the lesser effectiveness of the regimen in patients with initial resistance to fluoroquinolones and support the use of high-dose isoniazid, but do not support exclusion of patients for resistance to drugs other than fluoroquinolones. FUNDING: Expertise-France and Agence Française de Développement.

World Health Organization 2018 treatment guidelines for rifampicin-resistant tuberculosis: uncertainty, potential risks and the way forward.

The 2018 World Health Organization (WHO) treatment guidelines for multidrug-/rifampicin-resistant tuberculosis (MDR/RR-TB) give preference to all-oral long regimens lasting for 18-20 months. The guidelines strongly recommend combining bedaquiline, levofloxacin (or moxifloxacin) and linezolid, supplemented by cycloserine and/or clofazimine. The effectiveness of this combination in a long regimen has not been tested in any study to date, with corresponding uncertainty. The guidelines indicate that, ideally, all MDR-TB patients should have - as a minimum - the isolate tested for fluoroquinolones, bedaquiline and linezolid susceptibility before the start of treatment. Unfortunately, the capacity for drug susceptibility testing is insufficient in resource-limited settings. The risk of acquired bedaquiline resistance cannot be ignored, especially in patients with undetected resistance to fluoroquinolones. Both linezolid and cycloserine are known for their high frequency of serious adverse events. The combination of bedaquiline, moxifloxacin and clofazimine in the same regimen may excessively increase the QT interval. These expected adverse effects are difficult to monitor and manage in resource-limited settings, and may result in frequent modifications and a less effective regimen. The final STREAM results have confirmed the non-inferiority of the short regimen compared with the long regimen. Before evidence on the all-oral long and modified all-oral short treatment regimens is available, the WHO-recommended short MDR-TB regimens, with monitoring for ototoxicity, remain a better treatment option for the management of MDR/RR-TB patients who are eligible for short regimens in low- and middle-income countries. National tuberculosis programmes should also strengthen their capacity in the detection and management of fluoroquinolone-resistant MDR-TB following the WHO guidelines.

Standardised shorter regimens versus individualised longer regimens for rifampin- or multidrug-resistant tuberculosis.

We sought to compare the effectiveness of two World Health Organization (WHO)-recommended regimens for the treatment of rifampin- or multidrug-resistant (RR/MDR) tuberculosis (TB): a standardised regimen of 9-12 months (the "shorter regimen") and individualised regimens of ≥20 months ("longer regimens").We collected individual patient data from observational studies identified through systematic reviews and a public call for data. We included patients meeting WHO eligibility criteria for the shorter regimen: not previously treated with second-line drugs, and with fluoroquinolone- and second-line injectable agent-susceptible RR/MDR-TB. We used propensity score matched, mixed effects meta-regression to calculate adjusted odds ratios and adjusted risk differences (aRDs) for failure or relapse, death within 12 months of treatment initiation and loss to follow-up.We included 2625 out of 3378 (77.7%) individuals from nine studies of shorter regimens and 2717 out of 13 104 (20.7%) individuals from 53 studies of longer regimens. Treatment success was higher with the shorter regimen than with longer regimens (pooled proportions 80.0% versus 75.3%), due to less loss to follow-up with the former (aRD -0.15, 95% CI -0.17- -0.12). The risk difference for failure or relapse was slightly higher with the shorter regimen overall (aRD 0.02, 95% CI 0-0.05) and greater in magnitude with baseline resistance to pyrazinamide (aRD 0.12, 95% CI 0.07-0.16), prothionamide/ethionamide (aRD 0.07, 95% CI -0.01-0.16) or ethambutol (aRD 0.09, 95% CI 0.04-0.13).In patients meeting WHO criteria for its use, the standardised shorter regimen was associated with substantially less loss to follow-up during treatment compared with individualised longer regimens and with more failure or relapse in the presence of resistance to component medications. Our findings support the need to improve access to reliable drug susceptibility testing.

Short-Course Regimen for Multidrug-Resistant Tuberculosis: A Decade of Evidence.

About ten years ago, the first results of the so-called "Bangladesh regimen", a short regimen lasting nine months instead of 20 months, revolutionized multidrug-resistant tuberculosis (MDR-TB) treatment. Similar short regimens were studied in different settings, relying for their efficacy on a later generation fluoroquinolone, either gatifloxacin, moxifloxacin, or levofloxacin. We review the published material on short MDR-TB regimens, describe their different compositions, their results in national tuberculosis programs in middle- and low-income countries, the risk of acquiring resistance to fluoroquinolone, and the occurrence of adverse events. With over 80% success, the regimen performs much better than longer regimens (usually around 50%). Monitoring of adverse events allows adapting its composition to prevent severe adverse events such as deafness. We discuss the current applicability and usefulness of the short injectable-containing regimen given the 2019 recommendation of the World Health Organization (WHO) for a new long all-oral regimen. We conclude that the most effective fluoroquinolone is gatifloxacin, currently not listed as an essential medicine by WHO. It is a priority to restore its status as an essential medicine.

Half of rifampicin-resistant Mycobacterium tuberculosis complex isolated from tuberculosis patients in Sub-Saharan Africa have concomitant resistance to pyrazinamide.

BACKGROUND: Besides inclusion in 1st line regimens against tuberculosis (TB), pyrazinamide (PZA) is used in 2nd line anti-TB regimens, including in the short regimen for multidrug-resistant TB (MDR-TB) patients. Guidelines and expert opinions are contradictory about inclusion of PZA in case of resistance. Moreover, drug susceptibility testing (DST) for PZA is not often applied in routine testing, and the prevalence of resistance is unknown in several regions, including in most African countries. METHODS: Six hundred and twenty-three culture isolates from rifampicin-resistant (RR) patients were collected in twelve Sub-Saharan African countries. Among those isolates, 71% were from patients included in the study on the Union short-course regimen for MDR-TB in Benin, Burkina Faso, Burundi, Cameroon, Central Africa Republic, the Democratic Republic of the Congo, Ivory Coast, Niger, and Rwanda PZA resistance, and the rest (29%) were consecutive isolates systematically stored from 2014-2015 in Mali, Rwanda, Senegal, and Togo. Besides national guidelines, the isolates were tested for PZA resistance through pncA gene sequencing. RESULTS: Over half of these RR-TB isolates (54%) showed a mutation in the pncA gene, with a significant heterogeneity between countries. Isolates with fluoroquinolone resistance (but not with injectable resistance or XDR) were more likely to have concurrent PZA resistance. The pattern of mutations in the pncA gene was quite diverse, although some isolates with an identical pattern of mutations in pncA and other drug-related genes were isolated from the same reference center, suggesting possible transmission of these strains. CONCLUSION: Similar to findings in other regions, more than half of the patients having RR-TB in West and Central Africa present concomitant resistance to PZA. Further investigations are needed to understand the relation between resistance to PZA and resistance to fluoroquinolones, and whether continued use of PZA in the face of PZA resistance provides clinical benefit to the patients.

Follow-up and tracing of tuberculosis patients who fail to attend their scheduled appointments in Cotonou, Benin: a retrospective cohort study.

BACKGROUND: In the "Centre National Hospitalier de Pneumo-Phtisiologie" of Cotonou, Benin, little is known about the characteristics of patients who have not attended their scheduled appointment, the results of tracing and the possible benefits on improving treatment outcomes. This study aimed to determine the contribution of tracing activities for those who missed scheduled appointments towards a successful treatment outcome. METHODS: A retrospective cohort study was carried out among all smear-positive pulmonary tuberculosis patients treated between January and September 2013. Data on demographic and diagnostic characteristics and treatment outcomes were accessed from tuberculosis registers and treatment cards. Information on those who missed their scheduled appointments was collected from the tracing tuberculosis register. A univariate analysis was performed to explore factors associated with missing a scheduled appointment. RESULTS: Of 457 patients (410 new smear-positive and 47 retreatment tuberculosis), 37 (8%) missed one or more of their appointments with a total of 44 episodes of missed appointments. The 3.5th (32%) and 5th (43%) month appointments were the ones most likely to be missed. Being male was associated with a higher risk of missing appointments (RR = 4.2; 95% CI = 1.5-11.8, p = 0.004) while having HIV infection was associated with a lower risk (RR = 0.3, 95% CI = 0.1-0.9, p = 0.03). Principal reasons for missed appointments were travelling outside Cotonou (34%) and feeling better (21%). In 24 (55%) of these 44 episodes of missed appointments, contact was made with the patient who returned to the programme. These follow-up activities increased the treatment success by 4%. CONCLUSION: In Cotonou, Benin, less than 10% of tuberculosis patients miss at least one of their scheduled appointments. Tracing activities increase the treatment success rate by 4% and current on-going practices in the Programme need to be endorsed and encouraged.

The majority of patients with multidrug-resistant tuberculosis in Sub-Saharan Africa present a concomitant resistance to pyrazinamide.

OBJECTIVE/BACKGROUND: Pyrazinamide (PZA) is an antibacterial used in the first-line regimen against tuberculosis (TB) for its action against dormant bacilli. PZA is also included in the new short regimen to treat multidrug-resistant TB (MDR-TB). However, the prevalence and significance of PZA resistance is not known in Central and West Africa. METHODS: Between 2013 and 2016, we collected samples from MDR-TB patients recruited in an observational study implementing the new short MDR-TB regimen in six countries: Burundi (n=35), Cameroon (n=135), Niger (n=57), Central African Republic (n=35), Democratic Republic of the Congo (n=99), and Rwanda (n=16). Resistance to rifamipicine, isoniazide, injectables, and fluoroquinolones was tested by phenotypic (live strains) or genotypic methods (inactivated strains). Resistance to PZA was analyzed through sequencing of the pncA gene. Relevance of mutations was established based on recent literature. RESULTS: From 377 patients with MDR-TB, 354 (94%) samples were successfully sequenced. Among those, 53% (189) presented a mutation in pncA that confers a reported (121), potential (56), or unclear (12) resistance. Furthermore, six isolates presented a mutation associated with PZA sensitivity. The frequency of resistance per country was 26% in Central African Republic, 39% in Niger, 49% in Cameroon, 66% in Burundi, 68% in Democratic Republic of the Congo, and 87% in Rwanda. Isolates presented 109 different profiles of mutations, including 73 occurring only once. Codon 12 was most frequently affected (15 isolates), including 10 isolates with Asp12Ala. These 10 isolates came from three different countries, and presented different profiles of resistance to other drugs. The two next most frequent mutations, Met175Ile and Gln10Pro (8 isolates and 7 isolates, respectively), each suggest clusters of transmission, with similar geographical and resistance characteristics. Moreover, four isolates presented two simultaneous genetic variations, and 11 patients had a mix of sensitive and resistant bacilli. Preliminary data tend to indicate that patients carrying a PZA-resistant isolate had a higher failure rate on the new short MDR-TB treatment regimen (7% vs. 3%). All isolates resistant to injectables (4) and most (19/21) of those resistant to fluoroquinolones, including two extremely-resistant TB isolates, were also resistant to PZA. CONCLUSION: Similar to other regions in the world, the majority of MDR-TB strains from Sub-Saharan Africa countries are resistant to PZA, albeit with diverse rates between countries. We identified a diverse range of mutations in pncA, with 30% of them not previously reported. The impact of such resistance on the success of the short MDR-TB regimen will require more investigation.

National profile and treatment outcomes of patients with extrapulmonary tuberculosis in Bénin.

BACKGROUND: In sub-Saharan Africa, there is a dearth of published literature on extrapulmonary tuberculosis (EPTB). OBJECTIVE: To describe demographic, diagnostic and HIV-status characteristics of patients with EPTB in Bénin, their treatment outcomes, and among those who completed their treatment in the Centre National Hospitalier de Pneumo-Phtisiologie (CNHP-P), the proportion whose bodyweight increased during treatment. MATERIAL AND FINDINGS: This was a retrospective cohort study with comparisons made between EPTB and new smear-positive pulmonary tuberculosis (NPTB) patients diagnosed in the country from January to December 2011. There were 383 EPTB patients (9% of all TB cases) with a mean age of 35 years, male/female ratio of 1.3 and important regional variation. There were significantly more females (p = 0.001), children <15 years (p<0.001) and HIV-positive patients (p = 0.005) with EPTB compared with NPTB. Pleural effusion, spinal and lymph node tuberculosis accounted for 66% of all EPTB. Children <15 years represented 16% of cases, with lymph node disease being most common among them (p<0.001). Of 130 EPTB patients registered in CNHP-P, 7% had a confirmed bacteriological/histological diagnosis. There were 331 (86%) patients who successfully completed treatment. More patients with EPTB were lost-to-follow-up compared with NPTB (p<0.001) with all these patients from one region. The best treatment completion rates were in children <15 years (OR:3.5, 95%CI:1.0-14.8) while patients with pleural effusion and ascites had the worst outcomes. Of 72 HIV-coinfected patients, 88% were on antiretroviral therapy (ART). HIV-positive status was associated with poor outcomes while those on ART fared better. In the CNHP-P, more than 80% who completed their treatment showed an increase in bodyweight and this was more evident in HIV-positive compared with HIV-negative patients (p = 0.03). CONCLUSION: Patients with EPTB generally do well in Bénin, although the TB Programme would benefit through more attention to accurate diagnosis and earlier start of ART in HIV-infected patients.

National profile and treatment outcomes of adult smear-negative pulmonary TB patients in Benin.

BACKGROUND: In Benin, patients with smear-negative pulmonary TB (SNPTB) are of low priority in the National Tuberculosis Programme (NTP) and little is known about their profile or treatment outcomes. METHODS: A retrospective cohort study was carried out to determine characteristics and treatment outcomes in all adults registered with SNPTB in 2009. Findings were compared with patients with new smear-positive pulmonary tuberculosis (PTB) diagnosed in the same period. RESULTS: Of 3140 patients with PTB, 273 (8.7%) had SNPTB, with higher rates in northern and southwestern regions. SNPTB was associated with female gender, older age and HIV-positive status (p<0.01). Patients with SNPTB had a higher proportion of unsuccessful treatment outcomes compared with smear-positive PTB owing to death and loss to follow-up (LFU) (p<0.01). The region with the capital city had the highest rate of LFU. Differences in unsuccessful outcomes between SNPTB and smear-positive PTB were more apparent in persons who were HIV-negative, and among HIV-positives not on antiretroviral treatment. CONCLUSION: In Benin, treatment outcomes of SNPTB patients were inferior to those with smear-positive PTB, with LFU being a major problem. The Benin NTP needs to better address the problem of patients with SNPTB in terms of monitoring and reporting, treatment management including that associated with HIV care, and reducing LFU.

Assessment of clofazimine activity in a second-line regimen for tuberculosis in mice.

RATIONALE: Although observational studies suggest that clofazimine-containing regimens are highly active against drug-resistant tuberculosis, the contribution of clofazimine for the treatment of this disease has never been systematically evaluated. OBJECTIVES: Our goal was to directly compare the activity of a standard second-line drug regimen with or without the addition of clofazimine in a mouse model of multidrug-resistant tuberculosis. Our comparative outcomes included time to culture conversion in the mouse lungs and the percentage of relapses after treatment cessation. METHODS: Mice were aerosol-infected with an isoniazid-resistant (as a surrogate of multidrug-resistant) strain of Mycobacterium tuberculosis. Treatment, which was administered for 5 to 9 months, was initiated 2 weeks after infection and comprised the following second-line regimen: daily (5 d/wk) moxifloxacin, ethambutol, and pyrazinamide, supplemented with amikacin during the first 2 months. One-half of the mice also received daily clofazimine. The decline in lung bacterial load was assessed monthly using charcoal-containing agar to reduce clofazimine carryover. Relapse was assessed 6 months after treatment cessation. MEASUREMENTS AND MAIN RESULTS: After 2 months, the bacillary load in lungs was reduced from 9.74 log10 at baseline to 3.61 and 4.68 in mice treated with or without clofazimine, respectively (P < 0.001). Mice treated with clofazimine were culture-negative after 5 months, whereas all mice treated without clofazimine remained heavily culture-positive for the entire 9 months of the study. The relapse rate was 7% among mice treated with clofazimine for 8 to 9 months. CONCLUSIONS: The clofazimine contribution was substantial in these experimental conditions.

Assessment of organizational measures to prevent nosocomial tuberculosis in health facilities of 4 sub-Saharan countries in 2010.

BACKGROUND: The prevention of tuberculosis (TB) transmission in healthcare settings is a major issue, particularly because of the interaction between human immunodeficiency virus and TB and the emergence of multidrug-resistant TB. SETTING: Healthcare facilities involved in TB management in 4 African countries (Benin, Cameroon, Cote d'Ivoire, and Togo). METHODS: A questionnaire was developed by representatives of the 4 countries to evaluate the organizational measures implemented in facilities involved in TB management. On-site visits were performed between July 2010 and July 2011. RESULTS: A total of 115 facilities, including 10 university hospitals and 92 basic management units, were visited. None had a TB infection control plan, and only 5.2% provided education for staff about nosocomial TB. Overall, 48.3% of the facilities performed triage of suspected TB cases on hospital arrival or admission, 89.6% provided education for TB cases on cough etiquette, 20.0% segregated smear-positive TB cases, and 15.7% segregated previously treated cases. A total of 15.5% of the facilities registered TB among staff, for a global prevalence rate of 348 cases per 100,000 staff members. CONCLUSION: This survey identified simple and mostly costless administrative measures to be urgently implemented at the local level to prevent nosocomial TB, such as staff education, triage on admission, and segregation of previously treated patients.