OBJECTIVES: To assess the performance of the GenoType MTBDR sl v1, a line-probe assay (LPA), to exclude baseline resistance to fluoroquinolones (FQs) and second-line injectables (SLIs) in the Standard Treatment Regimen of Anti-tuberculosis Drugs for Patients With MDR-TB 1 (STREAM 1) trial. METHODS: Direct sputum MTBDR sl results in the site laboratories were compared to indirect phenotypic drug susceptibility testing (pDST) results in the central laboratory, with DNA sequencing as a reference standard. RESULTS: Of 413 multidrug-resistant TB (MDR-TB) patients tested using MTBDR sl and pDST, 389 (94.2%) were FQ-susceptible and 7 (1.7%) FQ-resistant, while 17 (4.1%) had an inconclusive MTBDR sl result. For SLI, 372 (90.1%) were susceptible, 5 (1.2%) resistant and 36 (8.7%) inconclusive. There were 9 (2.3%) FQ discordant pDST/MTBDR sl results, of which 3 revealed a mutation and 5 (1.3%) SLI discordant pDST/MTBDR sl results, none of which were mutants on sequencing. Among the 17 FQ- and SLI MTBDR sl- inconclusive samples, sequencing showed 1 FQ- and zero SLI-resistant results, similar to frequencies among the conclusive MTBDR sl . The majority of inconclusive MTBDR sl results were associated with low bacillary load samples (acid-fast bacilli smear-negative or scantily positive) compared to conclusive results ( P < 0.001). CONCLUSION: MTBDR sl can facilitate the rapid exclusion of FQ and SLI resistances for enrolment in clinical trials.
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.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.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.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.
ABSTRACT Rifampicin heteroresistance – where rifampicin-resistant and -susceptible tuberculosis (TB) bacilli co-exist – may result in failed standard TB treatment and potential spread of rifampicin-resistant strains. Detection of rifampicin heteroresistance in routine rapid diagnostic tests (RDTs) allows for patients to receive prompt and effective multidrug-resistant-TB treatment, and may improve rifampicin-resistant TB control. The limit of detection (LOD) of rifampicin heteroresistance for phenotypic drug susceptibility testing by the proportion method is 1%, yet is insufficiently documented for RDTs. We therefore aimed to determine, for the four RDTs (XpertMTB/RIF, XpertMTB/RIF Ultra, GenoTypeMTBDR plus v2.0, and GenoscholarNTM+MDRTBII), the LOD per probe and mutation, validated by colony-forming-unit-counting and targeted deep sequencing (Deeplex-MycTB). We selected one rifampicin-susceptible and four rifampicin-resistant strains, with mutation D435V, H445D, H445Y, and S450L respectively, mixed them in various proportions in triplicate, tested them with each RDT, and determined the LODs per mutation type. Deeplex-MycTB revealed concordant proportions of the minority resistant variants in the mixtures. The Deeplex-MycTB-validated-LODs ranged from 20-80% for XpertMTB/RIF, 20-70% for Xpert Ultra, 5-10% for GenoTypeMTBDR plus v2.0, and 1-10% for GenoscholarNTM+MTBII for the different mutations. Deeplex-MycTB, GenoTypeMTBDR plus v2.0, and GenoscholarNTM+MDRTBII, provide explicit information on rifampicin heteroresistance for the most frequently detected mutations. Classic Xpert and Ultra report rifampicin heteroresistance as rifampicin resistance, while Ultra may denote rifampicin heteroresistance through ‘mixed patterns’ of wild-type and mutant melt probe melt peak temperatures. Overall, our findings inform end-users that the threshold for reporting resistance in case of rifampicin heteroresistance is the highest for Classic Xpert and Ultra, to resolve phenotypic and genotypic discordant rifampicin-resistant TB results.
Shortening the course of treatment for tuberculosis would be a major improvement for case management and disease control. This phase 3 trial assessed the efficacy and safety of a 4-month gatifloxacin-containing regimen for treating rifampin-sensitive pulmonary tuberculosis.We conducted a noninferiority, randomized, open-label, controlled trial involving patients 18 to 65 years of age with smear-positive, rifampin-sensitive, newly diagnosed pulmonary tuberculosis in five sub-Saharan African countries. A standard 6-month regimen that included ethambutol during the 2-month intensive phase was compared with a 4-month regimen in which gatifloxacin (400 mg per day) was substituted for ethambutol during the intensive phase and was continued, along with rifampin and isoniazid, during the continuation phase. The primary efficacy end point was an unfavorable outcome (treatment failure, recurrence, or death or study dropout during treatment) measured 24 months after the end of treatment, with a noninferiority margin of 6 percentage points, adjusted for country.A total of 1836 patients were assigned to the 4-month regimen (experimental group) or the standard regimen (control group). Baseline characteristics were well balanced between the groups. At 24 months after the end of treatment, the adjusted difference in the risk of an unfavorable outcome (experimental group [21.0%] minus control group [17.2%]) in the modified intention-to-treat population (1356 patients) was 3.5 percentage points (95% confidence interval, -0.7 to 7.7). There was heterogeneity across countries (P=0.02 for interaction, with differences in the rate of an unfavorable outcome ranging from -5.4 percentage points in Guinea to 12.3 percentage points in Senegal) and in baseline cavitary status (P=0.04 for interaction) and body-mass index (P=0.10 for interaction). The standard regimen, as compared with the 4-month regimen, was associated with a higher dropout rate during treatment (5.0% vs. 2.7%) and more treatment failures (2.4% vs. 1.7%) but fewer recurrences (7.1% vs. 14.6%). There was no evidence of increased risks of prolongation of the QT interval or dysglycemia with the 4-month regimen.Noninferiority of the 4-month regimen to the standard regimen with respect to the primary efficacy end point was not shown. (Funded by the Special Program for Research and Training in Tropical Diseases and others; ClinicalTrials.gov number, NCT00216385.).
Damien Foundation Project, Bangladesh.To evaluate sputum smear fluorescein diacetate (FDA) vital staining to predict culture-defined failure and rifampicin (RMP) resistance.A retrospective, operational study.A total of 1633 episodes of auramine smear-defined late conversion and failure could be evaluated (respectively 640 and 584 on first treatment and 185 and 224 on retreatment). Negative FDA was 95% predictive of negative culture in patients on first treatment, while its positive predictive value was around 95% during retreatment. The predictive value of a positive (not scanty) result for RMP resistance or environmental non-tuberculous mycobacteria (NTM) was at least 90%, except in late converters on first-line treatment; a negative result was over 95% exclusive of the same except in retreatment failures. FDA correctly identified 88-98% of all RMP resistance.FDA staining increased the proportion of tuberculosis patients put on second-line treatment without receiving the standard first-line retreatment regimen. In our setting, with excellent microscopy, late case presentation and low resistance prevalence, it proved indispensable for efficient culture and referrals of early suspects for rapid drug susceptibility testing (DST). In other settings with low prevalence of NTM and difficult access to accurate and rapid DST, FDA-positive failures might even be considered for immediate start of second-line treatment.
To estimate the population prevalence of active pulmonary tuberculosis in Gambia.Between December 2011 and January 2013, people aged ≥ 15 years participating in a nationwide, multistage cluster survey were screened for active pulmonary tuberculosis with chest radiography and for tuberculosis symptoms. For diagnostic confirmation, sputum samples were collected from those whose screening were positive and subjected to fluorescence microscopy and liquid tuberculosis cultures. Multiple imputation and inverse probability weighting were used to estimate tuberculosis prevalence.Of 100 678 people enumerated, 55 832 were eligible to participate and 43 100 (77.2%) of those participated. A majority of participants (42 942; 99.6%) were successfully screened for symptoms and by chest X-ray. Only 5948 (13.8%) were eligible for sputum examination, yielding 43 bacteriologically confirmed, 28 definite smear-positive and six probable smear-positive tuberculosis cases. Chest X-ray identified more tuberculosis cases (58/69) than did symptoms alone (43/71). The estimated prevalence of smear-positive and bacteriologically confirmed pulmonary tuberculosis were 90 (95% confidence interval, CI: 53-127) and 212 (95% CI: 152-272) per 100 000 population, respectively. Tuberculosis prevalence was higher in males (333; 95% CI: 233-433) and in the 35-54 year age group (355; 95% CI: 219-490).The burden of tuberculosis remains high in Gambia but lower than earlier estimates of 490 per 100 000 population in 2010. Less than half of all cases would have been identified based on smear microscopy results alone. Successful control efforts will require interventions targeting men, increased access to radiography and more accurate, rapid diagnostic tests.Estimer la prévalence de la tuberculose pulmonaire active dans la population de Gambie.Entre décembre 2011 et janvier 2013, dans le cadre d'une enquête nationale en grappes à plusieurs degrés, un dépistage de la tuberculose pulmonaire active a été réalisé au moyen d'un questionnaire sur les symptômes tuberculeux et d'une radiographie pulmonaire, chez des personnes âgées de 15 ans ou plus ayant consenti à participer. Pour confirmer le diagnostic, des échantillons d'expectoration ont été collectés pour tous les participants dont les résultats de dépistage s’étaient révélés positifs, en vue de réaliser des examens par microscopie de fluorescence et des cultures en milieu liquide. Les techniques d'imputation multiple et de pondération par l'inverse de la probabilité ont été utilisées pour estimer la prévalence de la tuberculose.Sur les 100 678 personnes recensées, 55 832 étaient éligibles pour participer à l'étude et, parmi elles, 43 100 personnes (77,2%) ont participé. La majorité des participants (42 942; 99,6%) ont effectivement répondu au questionnaire sur les symptômes et passé une radiographie pulmonaire. Seules 5 948 personnes (13,8%) ont été éligibles pour un examen des expectorations, ce qui a entraîné le dépistage de 43 cas de tuberculose confirmée bactériologiquement, de 28 cas formels de tuberculose à frottis positif et de 6 cas probables de tuberculose à frottis positif. Les radiographies pulmonaires ont permis d'identifier plus de cas de tuberculose (58/69) que le seul questionnaire sur les symptômes (43/71). Les prévalences de la tuberculose pulmonaire à frottis positif et de la tuberculose bactériologiquement confirmée ont respectivement été estimées à 90 cas (intervalle de confiance de 95%: 53–127) pour 100 000 habitants et 212 cas (IC 95%: 152–272) pour 100 000 habitants. La prévalence de la tuberculose s'est avérée plus élevée dans la population masculine (333 cas; IC 95%: 233–433) et dans la tranche des 35–54 ans (355; IC 95%: 219-490).La charge de la tuberculose reste élevée en Gambie, même si elle a baissé par rapport à la précédente estimation, réalisée en 2010, qui faisait état de 490 cas pour 100 000 habitants. En utilisant uniquement la microscopie des frottis, moins de la moitié des cas auraient été identifiés. Pour être efficaces, les efforts de lutte contre la tuberculose doivent inclure des campagnes ciblant les hommes, améliorer l'accessibilité des examens radiographiques et utiliser des tests diagnostiques rapides plus précis.Estimar la prevalencia de la tuberculosis pulmonar activa entre la población en Gambia.Entre diciembre de 2011 y enero de 2013, personas de 15 años o más que participaron en una encuesta nacional en varias etapas y a nivel de grupos fueron examinadas en busca de tuberculosis pulmonar activa mediante una radiografía de tórax y para encontrar síntomas de tuberculosis. Para confirmar el diagnóstico, se recolectaron muestras de esputo de las personas cuyo examen resultó positivo y se sometieron a microscopia de fluorescencia y cultivos líquidos de tuberculosis. Para calcular la prevalencia de la tuberculosis, se utilizaron varias asignaciones y análisis de probabilidad inversa.De las 100 678 personas enumeradas, 55 832 se consideraron aptas para participar, de las cuales 43 100 (77,2%) participaron. La mayoría de los participantes (42 942; 99,6%) fueron examinados con éxito para detectar síntomas, así como por radiografía del tórax. Solo 5 948 (13,8%) fueron aptos para pruebas de esputo, lo que dio lugar a 43 confirmados a nivel bacteriológico, 28 casos bacilíferos de tuberculosis definitivos y 6 casos bacilíferos de tuberculosis probable. Las radiografías del tórax identificaron más casos de tuberculosis (58/69) que los síntomas por sí solos (43/71). La prevalencia estimada de tuberculosis pulmonar bacilífera y confirmada a nivel bacteriológico fue de 90 (intervalo de confianza, IC, del 95%: 53–127) y 212 (IC del 95%: 152–272) por cada 100 000 habitantes, respectivamente. La prevalencia de la tuberculosis fue mayor en hombres (333; IC del 95%: 233–433) y en los grupos de edad entre 35 y 54 años (355; IC del 95%: 219–490).Los índices de tuberculosis siguen siendo altos en Gambia, pero inferiores a las estimaciones anteriores de 490 por cada 100 000 habitantes en 2010. Se identificaron menos de la mitad de todos los casos según los resultados de la microscopia de frotis por sí solos. Para que los esfuerzos de control tengan éxito, serán necesarias intervenciones enfocadas a los hombres, un mayor acceso a radiografías y pruebas de diagnóstico más rápidas y exactas.تقدير مدى تفشي مرض السل الرئوي النشط بين السكان في غامبيا.خضع الأشخاص الذين تبلغ أعمارهم 15 عامًا أو أكثر ممن شاركوا في مسح عنقودي متعدد المراحل على مستوى الدولة بأكملها في الفترة بين ديسمبر/كانون الأول 2011 ويناير 2013 لفحص للكشف عن الإصابة بالسل الرئوي النشط باستخدام تصوير الصدر بالأشعة وفحص للكشف عن أعراض السل. وللتأكد من التشخيص، تم جمع عينات من البصاق من الأشخاص الذين أظهر الفحص نتائج إيجابية لهم، وخضعت تلك العينات للفحص تحت المجهر الفلوري ولعمليات زراعة في وسط سائل للكشف عن بكتريا السل. وتمت الاستعانة بطريقة حساب القيم التعويضية المتعددة وأسلوب ترجيح الاحتمال العكسي في تقدير مدى تفشي مرض السل. ا لنتائج بلغ عدد الأشخاص المؤهلين للمشاركة 55,832 شخص من بين الأشخاص الذين تم إحصاء أعدادهم والتي بلغت 100,678، وقد شارك منهم بالفعل 43,100 شخص (بنسبة 77.2%). وخضع معظم المشاركين (42942؛ بنسبة 99.6%) لإجراء ناجح للفحص الذي يكشف عن ظهور أعراض المرض وذلك الذي يعتمد على تصوير الصدر بالأشعة السينية. وبلغ عدد المؤهلين لاختبار البصاق 5948 شخصًا فقط (بنسبة 13.8%)، حيث ظهر من بين هؤلاء الأشخاص حالات للإصابة بالسل تم تأكيد تشخيصها بالطرق البكتريولوجية لدى 43 شخصًا، وتأكدت النتائج الإيجابية لفحص المسحة لدى 28 شخصًا، وأظهر ستة أشخاص نتائج إيجابية محتملة لفحص المسحة تشير للإصابة بالمرض. وتم تحديد المزيد من حالات الإصابة بالسل (58/69) من خلال تصوير الصدر بالأشعة السينية مقارنةً باستخدام الكشف عن ظهور الأعراض فقط (43/71). ووفقًا للتقديرات، فإن تفشي حالات الإصابة بالسل الرئوي التي تم تأكيد تشخيصها من خلال النتائج الإيجابية لفحص مسحة البصاق والطرق البكتريولوجية بلغ معدلًا مقداره 90 حالة (بنسبة أرجحية مقدارها 95%: 53 – 127) و212 حالة (بنسبة أرجحية مقدارها 95%: 152 – 272) في كل مجموعة سكانية يبلغ عدد أفرادها 100,000 نسمة، على التوالي. وارتفعت نسبة تفشي مرض السل عند الذكور (333؛ بنسبة أرجحية مقدارها 95%: 233 – 433) وكذلك في المجموعة العمرية من سن 35 إلى 54 عامًا (355؛ بنسبة أرجحية مقدارها 95%: 219–490).يظل عبء مرض السل بمعدل مرتفع في غامبيا، إلا أنه يقل عن التقديرات السابقة التي أشارت إلى وجود 490 حالة في كل مجموعة سكانية يبلغ عدد أفرادها 100,000 نسمة في عام 2010. وقد تم تحديد ما يقل عن النصف من الحالات بأكملها اعتمادًا على نتائج الفحص المجهري لمسحة البصاق وحده. وستتطلب الجهود الرامية للنجاح في السيطرة على المرض بعض التدخلات التي تستهدف الرجال، وزيادة فرص الخضوع للتصوير بالأشعة وتوفير المزيد من الاختبارات التشخيصية الدقيقة والسريعة.旨在预测冈比亚境内活动性肺结核患病率。.在 2011 年 12 月到 2013 年 1 月期间，研究人员采用 X 线胸片对年龄为 15 岁以及上参与全国范围内、多阶段整群调查的人员进行活动性肺结核筛查以及肺结核症状筛查。为进行确诊，研究人员采集了筛查结果阳性人员的痰液样本并对其进行荧光显微镜观察以及肺结核液体培养基培养。还采用多重填补法和逆概率加权法以估算肺结核患病率。.在选出的 100,678 人中，55 ,832 人有资格参与调查，其中 43,100 (77.2%) 人参与了调查。我们通过 X 线胸片成功地对大部分参与者（42,942 人；99.6%）进行了症状筛查。仅 5,948 (13.8%) 人有资格参加痰液检验，结果显示 43 人为细菌学检查阳性，28 人痰涂片检查为阳性，并且发现了六例痰涂片检查疑似阳性的肺结核病例。相对于单纯症状查痰法 (43/71)， X 线胸片可确诊更多肺结核病例 (58/69)。每 10 万人中，预计痰涂片阳性和细菌学检查阳性的肺结核患病人数分别为 90（95% 置信区间，CI: 53-127) 和 212 (95% 置信区间，CI: 152–272)。男性 (333; 95% CI: 233–433) 以及年龄介于 35–54 岁的人群 (355; 95% CI: 219–490) 肺结核患病率更高 。.冈比亚境内肺结核患病率居高不下，但低于 2010 年估计的每 10 万人中 490 例的患病率。在所有病例中，半数以下病例本可以仅仅通过显微镜观察痰涂片确诊。为有效控制疾病发展，需要对男性采取干预措施、进一步促进 X线胸片以及更多精确、快速诊断检测方法的普及。.Оценить популяционную распространенность активной формы туберкулеза легких в Гамбии.В период с декабря 2011 года по январь 2013 года лица в возрасте ≥□15 лет принимали участие в национальном многоэтапном исследовании с применением гнездовой выборки; их обследовали на наличие активной формы туберкулеза легких при помощи рентгенографии грудной клетки, а также проверяли наличие у них клинических симптомов туберкулеза. С целью подтверждения диагноза у лиц, для которых результаты скринингового обследования были положительными, брали пробу мокроты и подвергали ее флуоресцентной микроскопии, а также применяли ее посев на жидкую питательную среду. Для оценки распространенности туберкулеза применялся метод множественного восстановления пропущенных данных и метод весовых коэффициентов для величин, обратных вероятности.Из 100 678 человек, зарегистрированных для проведения обследования, 55 832 отвечали критериям исследования. Из них 43 100 человек (77,2%) приняли участие в исследовании. В большинстве своем участники (42 942 (99,6%)) успешно прошли скрининг симптомов и рентгенографию грудной клетки. Только 5 948 участников (13,8%) отвечали критериям для сдачи мокроты на анализ, из них в 43 случаях было получено бактериологическое подтверждение, 28 мазков были квалифицированы как достоверно положительные, шесть — как вероятные случаи туберкулеза. Рентгенография грудной клетки выявила больше случаев туберкулеза (58 из 69), чем диагностика только по симптомам (43 из 71). Оценка распространенности положительного мазка на туберкулез и бактериологически подтвержденного туберкулеза легких составила 90 (95%-й доверительный интервал, ДИ: 53–127) и 212 (95%-й ДИ: 152–272) на 100 000 населения соответственно. Туберкулез чаще встречался среди мужчин (333, 95%-й ДИ: 233–433) и лиц в возрасте 35–54 лет (355, 95%-й ДИ: 219–490).В Гамбии сохраняется высокое бремя туберкулеза, но полученные оценочные значения ниже величины, рассчитанной в 2010 году, в 490 случаях на 100 000 населения. Менее половины всех случаев могли быть выявлены только на основании микроскопического исследования мазка. Для успеха контролирующих мероприятий потребуются вмешательства, ориентированные на мужчин, более широкий доступ к рентгенографии и более точные и быстродействующие диагностические тесты.
'%3e%3cpath fill='%23012169' d='M0 0v30h60V0z'/%3e%3cpath stroke='%23fff' stroke-width='6' d='m0 0 60 30m0-30L0 30'/%3e%3cpath stroke='%23C8102E' stroke-width='4' d='m0 0 60 30m0-30L0 30' clip-path='url(%23b)'/%3e%3cpath stroke='%23fff' stroke-width='10' d='M30 0v30M0 15h60'/%3e%3cpath stroke='%23C8102E' stroke-width='6' d='M30 0v30M0 15h60'/%3e%3c/g%3e%3c/svg%3e)
'%3e%3cpath fill='%23001489' d='M0 0v6h9V0z'/%3e%3cpath fill='%23e03c31' d='M0 0v3h9V0z'/%3e%3cg stroke='%23fff' stroke-width='2'%3e%3cpath id='d' d='m0 0 4.5 3L0 6m4.5-3H9'/%3e%3cuse xlink:href='%23b' stroke='%23ffb81c' clip-path='url(%23c)'/%3e%3c/g%3e%3cuse xlink:href='%23d' fill='none' stroke='%23007749' stroke-width='1.2'/%3e%3c/g%3e%3c/svg%3e)