Operational research as a mechanism to improve treatment outcomes for drug-resistant TB in the WHO European Region.

In 2022, the WHO European Region accounted for 15.1% of all incident rifampicin-resistant/multidrug-resistant TB (RR/MDR-TB) cases. Most occurred in 18 high-priority countries of eastern Europe and central Asia, many of which joined an initiative led by the WHO Regional Office for Europe. The aim was to introduce three, fully oral, 9-month modified shorter treatment regimens (mSTR) to treat RR/MDR-TB under operational research conditions. The three regimens were: 1) bedaquiline + linezolid + levofloxacin + clofazimine + cycloserine (BdqLzdLfxCfzCs); 2) BdqLzdLfxCfz + delamanid (Dlm) for children over 6 years of age and adults; and 3) DlmLzdLfxCfz for children under 6 years of age. The project aimed to enhance treatment success, facilitate mSTR implementation, promote quality of care and build research capacity, while also contributing to global knowledge on all-oral mSTR use. Between April 2020 and June 2022, >2,800 patients underwent mSTR treatment in the WHO European Region. This unique experience promoted further collaboration with national tuberculosis programmes, health authorities, experts and donors within and outside Europe, with a focus on implementing operational research and improving the quality of care in high TB burden countries of the region. In the hope of encouraging others to adopt this model, we have described the principles of the initiative, its strengths and weaknesses and next steps.

En 2022, la Région européenne de l'OMS a recensé 15,1% de l'ensemble des cas de TB résistante à la rifampicine/multirésistante aux médicaments (RR/MDR-TB). La majorité de ces cas ont eu lieu dans 18 pays hautement prioritaires d'Europe orientale et d'Asie centrale, parmi lesquels de nombreux ont adhéré à une initiative dirigée par le Bureau régional de l'OMS pour l'Europe. L'objectif était de mettre en place trois schémas thérapeutiques modifiés plus courts de 9 mois, entièrement oraux, (mSTR, pour l'anglais "fully oral, 9-month modified shorter treatment regimens ¼) pour le traitement de la RR/MDR-TB dans le cadre d'une recherche opérationnelle. Ces trois schémas étaient les suivants 1) bédaquiline + linézolide + lévofloxacine + clofazimine + cyclosérine (BdqLzdLfxCfzCs) ; 2) BdqLzdLfxCfz + delamanid (Dlm) pour les enfants de plus de 6 ans et les adultes ; et 3) DlmLzdLfxCfz pour les enfants de moins de 6 ans. Le projet visait à améliorer l'efficacité des traitements, à faciliter l'application des mSTR, à promouvoir la qualité des soins et à renforcer les capacités de recherche, tout en contribuant aux connaissances mondiales sur l'utilisation des mSTR par voie orale. Entre avril 2020 et juin 2022, plus de 2 800 patients ont reçu un traitement par mSTR dans la Région Européenne de l'OMS. Cette expérience unique a encouragé la continuation de la collaboration avec les programmes nationaux de lutte contre la TB, les autorités sanitaires, les experts et les donateurs tant en Europe qu'à l'étranger. L'accent est mis sur la mise en œuvre de la recherche opérationnelle et l'amélioration de la qualité des soins dans les pays de la région où la TB est fortement prévalente. Nous avons détaillé les principes de l'initiative, ses avantages et ses inconvénients, dans l'espoir d'inciter d'autres pays à suivre cet exemple, tout en exposant les étapes à venir.

A 10-year review of isoniazid-resistant TB management in Uzbekistan 2009-2020.

BACKGROUND: Isoniazid (INH, H) resistance is the most common drug-resistant TB pattern, with treatment success rates lower than those in drug-susceptible TB. The WHO recommends a 6-month regimen of rifampicin (RIF, R), ethambutol (EMB, E), pyrazinamide (PZA, Z), and levofloxacin (Lfx) (6REZLfx) for INH-resistant, RIF-susceptible TB (HRRS-TB). Uzbekistan has a high burden of TB (62/100,000 population) and multidrug-resistant TB (12/100,000 population). METHODS: We conducted a retrospective, descriptive study of microbiologically confirmed HRRS-TB using routinely collected programmatic data from 2009 to 2020. RESULTS: We included 854 HRRS-TB cases. Treatment success was 80.2% overall. For REZLfx, the treatment success rate was 92.0% over a short treatment duration, with no amplifications to RIF or second-line anti-TB drug resistance. We documented 46 regimens with REZLfx plus linezolid (success 87.0%) and 539 regimens using kanamycin or capreomycin (success 76.6%). We identified 37 treatment failures (4.3%), 30 deaths (3.5%), 25 resistance amplifications (2.9%), including eight to RIF (0.9%), and 99 lost to follow-up (LTFU) cases (11.6%). Unsuccessful outcomes were more common with older age, diabetes, chest X-ray cavities, smear positivity, smear-positive persistence, and male sex. LTFU was more common with injection-containing regimens. CONCLUSIONS: REZLfx is a safe and effective first-line treatment for INH-resistant, RIF-susceptible TB. Treatment success was lower and LTFU was higher for injection-containing regimens.

CONTEXTE: La résistance à l'isoniazide (INH, H) est la forme de TB pharmacorésistante la plus courante, avec des taux de réussite thérapeutique inférieurs à ceux de la TB pharmacosensible. L'OMS recommande un traitement de six mois à base de rifampicine (RIF, R), d'éthambutol (EMB, E), de pyrazinamide (PZA, Z) et de lévofloxacine (LFx) (6REZLfx) pour la TB résistante à l'INH et sensible au RIF (HRRS-TB). En Ouzbékistan, la prévalence de la TB est élevée, avec un taux de 62 cas pour 100 000 habitants, ainsi que de la TB multirésistante, avec un taux de 12 cas pour 100 000 habitants. MÉTHODES: Une étude rétrospective et descriptive de la HRRS-TB confirmée microbiologiquement a été réalisée en utilisant des données programmatiques collectées de manière routinière de 2009 à 2020. RÉSULTATS: Nous avons inclus 854 cas de HRRS-TB. Le taux de réussite du traitement global était de 80,2%. Pour le traitement avec REZLfx, le taux de réussite était de 92,0% sur une courte durée, sans résistance au RIF ni aux médicaments antituberculeux de deuxième ligne. Nous avons observé 46 schémas thérapeutiques associant REZLfx et linézolide avec un taux de réussite de 87,0%, ainsi que 539 schémas thérapeutiques utilisant la kanamycine ou la capréomycine avec un taux de réussite de 76,6 %. Nous avons enregistré 37 échecs thérapeutiques (4,3%), 30 décès (3,5%), 25 cas de résistance amplifiée (2,9%), dont huit au RIF (0,9%), et 99 cas de perte de suivi (LTFU, pour l'anglais « loss to follow-up ¼) (11,6%). Les échecs étaient plus fréquents chez les patients âgés, diabétiques, présentant des cavités à la radiographie thoracique, un frottis positif persistant et de sexe masculin. La prolongation de la durée d'utilisation était plus fréquente avec les schémas contenant des injections. CONCLUSIONS: REZLfx est un traitement de première intention sûr et efficace contre la TB résistante à l'INH et sensible aux RIF. Le succès du traitement était plus faible et le nombre de LTFU était plus élevé pour les schémas contenant des injections.

Household drug-resistant TB contact tracing in Tajikistan.

BACKGROUND: Tajikistan has a high burden of rifampicin-resistant TB (RR-TB), with 2,700 new cases estimated for 2021 (28/100,000 population). TB is spread among household members through close interaction and children exposed through household contact progress to disease rapidly and frequently.METHODS: We retrospectively analysed programmatic data from household contact tracing in Dushanbe over 50 months. We calculated person-years of follow-up, contact tracing yield, number needed to screen (NNS) and number needed to test (NNT) to find one new case, and time to diagnosis.RESULTS: We screened 6,654 household contacts of 830 RR-TB index cases; 47 new RR-TB cases were detected, 43 in Year 1 and 4 in Years 2 or 3. Ten were aged <5 years; 46/47 had TB symptoms, 34/45 had chest radiographs consistent with TB, 11/35 were Xpert Ultra-positive, 29/32 were tuberculin skin test-positive and 28/47 had positive TB culture and phenotypic drug susceptibility results. The NNS to find one RR-TB case was 141.57 and the NNT was 34.49. The yields for different types of contacts were as follows: 0.7% for screened contacts, 2.9% for tested contacts, 17.0% for symptomatic contacts and 12.1% for symptomatic contacts aged below 5 years.CONCLUSION: RR-TB household contact tracing was feasible and productive in Tajikistan, a low middle-income country with an inefficient healthcare delivery system.

Clinical standards for drug-susceptible TB in children and adolescents.

BACKGROUND: These clinical standards aim to provide guidance for diagnosis, treatment, and management of drug-susceptible TB in children and adolescents.METHODS: Fifty-two global experts in paediatric TB participated in a Delphi consensus process. After eight rounds of revisions, 51/52 (98%) participants endorsed the final document.RESULTS: Eight standards were identified: Standard 1, Age and developmental stage are critical considerations in the assessment and management of TB; Standard 2, Children and adolescents with symptoms and signs of TB disease should undergo prompt evaluation, and diagnosis and treatment initiation should not depend on microbiological confirmation; Standard 3, Treatment initiation is particularly urgent in children and adolescents with presumptive TB meningitis and disseminated (miliary) TB; Standard 4, Children and adolescents should be treated with an appropriate weight-based regimen; Standard 5, Treating TB infection (TBI) is important to prevent disease; Standard 6, Children and adolescents should receive home-based/community-based treatment support whenever possible; Standard 7, Children, adolescents, and their families should be provided age-appropriate support to optimise engagement in care and clinical outcomes; and Standard 8, Case reporting and contact tracing should be conducted for each child and adolescent.CONCLUSION: These consensus-based clinical standards, which should be adapted to local contexts, will improve the care of children and adolescents affected by TB.

Impact of pyrazinamide resistance on multidrug-resistant tuberculosis in Karakalpakstan, Uzbekistan.

SETTING: The World Health Organization (WHO) recommends the inclusion of pyrazinamide (PZA) in treatment regimens for multidrug-resistant tuberculosis (MDR-TB) unless resistance has been confirmed. OBJECTIVE: To investigate the association between PZA susceptibility and MDR-TB treatment outcome among patients treated with a PZA-containing regimen and whether the duration of the intensive phase of the PZA-containing regimen affected treatment outcome. DESIGN: We conducted a retrospective cohort study including all eligible MDR-TB patients starting treatment in 2003-2013 in the TB programme in Karakalpakstan, Uzbekistan. PZA drug susceptibility testing (DST) using liquid culture was performed, and outcomes were classified according to the WHO 2013 definitions. RESULTS: Of 2446 MDR-TB patients included, 832 (34.0%) had an available baseline PZA DST result, 612 (73.6%) of whom were PZA-resistant. We found no association between treatment success and PZA susceptibility (adjusted odds ratio [aOR] 0.86, 95%CI 0.51-1.44, P = 0.6) in patients treated with PZA. Furthermore, among patients with no baseline PZA DST result, no evidence was seen of an association between treatment success and PZA treatment duration (aOR 0.86, 95%CI 0.49-1.51, P = 0.6). CONCLUSION: Treatment of MDR-TB with a standard PZA regimen does not appear to improve treatment outcomes, regardless of PZA susceptibility or duration of treatment.

Treating children for drug-resistant tuberculosis in Tajikistan with Group 5 medications.

BACKGROUND: Management of extensively drug-resistant tuberculosis (XDR-TB) and pre-XDR-TB is challenging, as effective drugs are lacking. Group 5 anti-tuberculosis drugs have an unclear role in the treatment of drug-resistant TB, and in children the efficacy, safety and effects of long-term use are not well described. We present clinical outcomes and adverse effects of a cohort of children with XDR-TB or pre-XDR-TB treated with Group 5 drugs in Tajikistan. METHODS: We conducted a retrospective analysis of eight children treated with one or more of the Group 5 drugs available under the Tajikistan National TB Programme-linezolid, amoxicillin-clavulanate, clofazimine and clarithromycin-given in combination with first- and second-line drugs. Time to sputum culture conversion, clinical outcomes and adverse effects were evaluated. RESULTS: Two children were cured, one completed treatment, four achieved favourable interim outcomes and one died. Adverse effects attributable to linezolid that required drug cessation occurred in one child; adverse effects of the other Group 5 drugs were insignificant or absent, requiring no regimen changes. CONCLUSION: Group 5 drugs can contribute to effective regimens in children with XDR and pre-XDR-TB. With proper monitoring and aggressive management of adverse effects, their safety profile might be acceptable, even in long-term use.