Undernourished Household Contacts Are at Increased Risk of Tuberculosis (TB) Disease, but not TB Infection- a Multicenter Prospective Cohort Analysis.

Undernutrition is the leading risk factor for tuberculosis (TB) globally and in India. This multicenter prospective cohort analysis from India suggests that undernutrition is associated with increased risk of TB disease but not TB infection among household contacts of persons with TB.

Outcomes for people with TB by disease severity at presentation.

There is substantial heterogeneity in disease presentation for individuals with TB disease, which may correlate with disease outcomes. We estimated disease outcomes by disease severity at presentation among individuals with TB during the pre-chemotherapy era.We extracted data on people with TB enrolled between 1917 and 1948 in the USA, stratified by three disease severity categories at presentation using the U.S. National Tuberculosis Association diagnostic criteria. These criteria were based largely on radiographic findings ("minimal", "moderately advanced", and "far advanced"). We used Bayesian parametric survival analysis to model the survival distribution overall, and by disease severity and Bayesian logistic regression to estimate the severity-level specific natural recovery odds within 3 years.People with minimal TB at presentation had a 2% (95% CrI 0-11%) probability of TB death within 5 years vs. 40% (95% CrI 15-68) for those with far advanced disease. Individuals with minimal disease had 13.62 times the odds (95% CrI 9.87-19.10) of natural recovery within 3 years vs. those with far advanced disease.Mortality and natural recovery vary by disease severity at presentation. This supports continued work to evaluate individualized (e.g., shortened or longer) regimens based on disease severity at presentation, identified using radiography..

Standards for clinical trials for treating TB.

BACKGROUND: The value, speed of completion and robustness of the evidence generated by TB treatment trials could be improved by implementing standards for best practice.METHODS: A global panel of experts participated in a Delphi process, using a 7-point Likert scale to score and revise draft standards until consensus was reached.RESULTS: Eleven standards were defined: Standard 1, high quality data on TB regimens are essential to inform clinical and programmatic management; Standard 2, the research questions addressed by TB trials should be relevant to affected communities, who should be included in all trial stages; Standard 3, trials should make every effort to be as inclusive as possible; Standard 4, the most efficient trial designs should be considered to improve the evidence base as quickly and cost effectively as possible, without compromising quality; Standard 5, trial governance should be in line with accepted good clinical practice; Standard 6, trials should investigate and report strategies that promote optimal engagement in care; Standard 7, where possible, TB trials should include pharmacokinetic and pharmacodynamic components; Standard 8, outcomes should include frequency of disease recurrence and post-treatment sequelae; Standard 9, TB trials should aim to harmonise key outcomes and data structures across studies; Standard 10, TB trials should include biobanking; Standard 11, treatment trials should invest in capacity strengthening of local trial and TB programme staff.CONCLUSION: These standards should improve the efficiency and effectiveness of evidence generation, as well as the translation of research into policy and practice.

Survival of people with untreated TB: effects of time, geography and setting.

BACKGROUND: An estimated 40% of people who developed TB in 2021 were not diagnosed or treated. Pre-chemotherapy era data are a rich resource on survival of people with untreated TB. We aimed to identify heterogeneities in these data to inform their more precise use.METHODS: We extracted survival data from pre-chemotherapy era papers reporting TB-specific mortality and/or natural recovery data. We used Bayesian parametric survival analysis to model the survival distribution, stratifying by geography (North America vs. Europe), time (pre-1930 vs. post-1930), and setting (sanitoria vs. non-sanitoria).RESULTS: We found 12 studies with TB-specific mortality data. Ten-year survival was 69% in North America (95% CI 54-81) and 36% in Europe (95% CI 10-71). Only 38% (95% CI 18-63) of non-sanitorium individuals survived to 10 years compared to 69% (95% CI 41-87) of sanitoria/hospitalized patients. There were no significant differences between people diagnosed pre-1930 and post-1930 (5-year survival pre-1930: 65%, 95% CI 44-88 vs. post-1930: 72%, 95% CI 41-94).CONCLUSIONS: Mortality and natural recovery risks vary substantially by location and setting. These heterogeneities need to be considered when using pre-chemotherapy data to make inferences about expected survival of people with undiagnosed TB.

Smoked drug use in patients with TB is associated with higher bacterial burden.

BACKGROUND: Smoking of illicit drugs may lead to more rapid TB disease progression or late treatment presentation, yet research on this topic is scant. We examined the association between smoked drug use and bacterial burden among patients newly initiated on drug-susceptible TB (DS-TB) therapy.METHODS: Data from 303 participants initiating DS-TB treatment in the Western Cape Province, South Africa, were analyzed. Smoked drug use was defined as self-reported or biologically verified methamphetamine, methaqualone and/or cannabis use. Proportional hazard and logistic regression models (adjusted for age, sex, HIV status and tobacco use) examined associations between smoked drug use and mycobacterial time to culture positivity (TTP), acid-fast bacilli sputum smear positivity and lung cavitation.RESULTS: People who smoked drugs (PWSD) comprised 54.8% (n = 166) of the cohort. TTP was faster for PWSD (hazard ratio 1.48, 95% CI 1.10-1.97; P = 0.008). Smear positivity was higher among PWSD (OR 2.28, 95% CI 1.22-4.34; P = 0.011). Smoked drug use (OR 1.08, 95% CI 0.62-1.87; P = 0.799) was not associated with increased cavitation.CONCLUSIONS: PWSD had a higher bacterial burden at diagnosis than those who do not smoke drugs. Screening for TB among PWSD in the community may facilitate earlier linkage to TB treatment and reduce community transmission.

Factors associated with screening failure and study withdrawal in multidrug-resistant TB.

SETTING: Multidrug-resistant TB (MDR-TB) clinical trial in Lima, Peru and Cape Town, South Africa.OBJECTIVE: To identify baseline factors associated with screening failure and study withdrawal in an MDR-TB clinical trial.DESIGN: We screened patients for a randomized, blinded, Phase II trial which assessed culture conversion over the first 6 months of treatment with varying doses of levofloxacin plus an optimized background regimen (ClinicalTrials.gov: NCT01918397). We identified factors for screening failure and study withdrawal using Poisson regression to calculate prevalence ratios and Cox proportional hazard regression to calculate hazard ratios. We adjusted for factors with P < 0.2.RESULTS: Of the 255 patients screened, 144 (56.5%) failed screening. The most common reason for screening failure was an unsuitable resistance profile on sputum-based molecular susceptibility testing (n = 105, 72.9%). No significant baseline predictors of screening failure were identified in the multivariable model. Of the 111 who were enrolled, 33 (30%) failed to complete treatment, mostly for non-adherence and consent withdrawal. No baseline factors predicted study withdrawal in the multivariable model.CONCLUSION: No baseline factors were independently associated with either screening failure or study withdrawal in this secondary analysis of a MDR-TB clinical trial.

Global availability of susceptibility testing for second-line anti-tuberculosis agents.

BACKGROUND: The continued development of new anti-TB agents brings with it a demand for accompanying treatment regimens to prevent the development of resistance. Effectively meeting this demand requires an understanding of the pathogen´s susceptibility to various treatment options, which in turn makes access to antibiotic susceptibility testing (AST) a paramount consideration in the global treatment of TB.METHODS: A 12-question, quantitative and qualitative survey was developed to gauge global capacity and access to AST. The survey was disseminated to members of the Global Laboratory Initiative, Global Drug-resistant TB Initiative, and the TB section of the International Union Against Tuberculosis and Lung Disease to solicit responses from pertinent stakeholders.RESULTS: A total of 323 complete responses representing 84 countries and all WHO Regions were collected. AST capacity for fluoroquinolones and second-line injectables was high in all WHO Regions. AST capacity for the new and repurposed drugs is highest in the European Region, Region of the Americas and the Western Pacific Region, but quite limited in the African and Eastern Mediterranean Regions. The AST turnaround time for second-line drugs was delayed compared to that for first-line drugs as samples needed to be sent farther for analysis. Common barriers to AST for second-line drugs were lack of specimen transportation infrastructure, high costs, and lack of specialised laboratory workers and specialised laboratory facilities.CONCLUSION: Without expanding global access to AST, the growing availability of new treatment options will likely be threatened by accompanying increase in resistance. There is an earnest and pressing need to improve capacity and access to AST alongside treatment options.

Seasonal drivers of tuberculosis: evidence from over 100 years of notifications in Cape Town.

BACKGROUND: Tuberculosis incidence varies seasonally in many settings. However, the role of seasonal variation in reactivation vs. transmission is unclear.METHODS: We reviewed data on TB notifications in Cape Town, South Africa, from 1903 to 2017 (exclusive of 1995-2002, which were unavailable). Data from 2003 onward were stratified by HIV status, age and notification status (new vs. retreatment). We performed seasonal decomposition and time-dependent spectral analysis using wavelets to assess periodicity over time. We estimated monthly peak-to-peak seasonal amplitude of notifications as a percentage of the annual notification rate.RESULTS: A seasonal trend was intermittently detected between 1904 and 1994, particularly during periods of high notification rates, but was consistently and strongly evident between 2003 and 2017, with peaks in September through November, following winter. Among young children, a second, higher seasonal peak was observed in March. Seasonal variation was greater in children (<5 years, 54%, 95% CI 47-61; 5-14 years, 63%, 95% CI 58-69) than in adults (36%, 95% CI 33-39).CONCLUSIONS: Stronger seasonal effects were seen in children, in whom progression following recent infection is known to be the predominant driver of disease. These findings may support increased transmission in the winter as an important driver of TB in Cape Town.

The impact of alcohol use on tuberculosis treatment outcomes: a systematic review and meta-analysis.

Alcohol use is associated with increased risk of developing tuberculosis (TB) disease, yet the impact of alcohol use on TB treatment outcomes has not been summarized. We aimed to quantitatively review evidence of the relationship between alcohol use and poor TB treatment outcomes. We conducted a systematic review of PubMed, EMBASE, and Web of Science (January 1980-May 2018). We categorized studies as having a high- or low-quality alcohol use definition and examined poor treatment outcomes individually and as two aggregated definitions (i.e., including or excluding loss to follow-up [LTFU]). We analyzed drug-susceptible (DS-) and multidrug-resistant (MDR-) TB studies separately. Our systematic review yielded 111 studies reporting alcohol use as a predictor of DS- and MDR-TB treatment outcomes. Alcohol use was associated with increased odds of poor treatment outcomes (i.e., death, treatment failure, and LTFU) in DS (OR 1.99, 95% CI 1.57-2.51) and MDR-TB studies (OR 2.00, 95% CI 1.73-2.32). This association persisted for aggregated poor treatment outcomes excluding LTFU, each individual poor outcome, and across sub-group and sensitivity analyses. Only 19% of studies used high-quality alcohol definitions. Alcohol use significantly increased the risk of poor treatment outcomes in both DS- and MDR-TB patients. This study highlights the need for improved assessment of alcohol use in TB outcomes research and potentially modified treatment guidelines for TB patients who consume alcohol.

Progress in global rollout of new multidrug-resistant tuberculosis treatments.

SETTING: The global multidrug-resistant tuberculosis (MDR-TB) epidemic has grown over the past decade and continues to be difficult to manage. In response, new drugs and treatment regimens have been recommended.OBJECTIVE: In 2017 and again in 2018, the International Union Against Tuberculosis and Lung Disease (The Union) drug-resistant (DR) TB Working Group collaborated with RESIST-TB to implement an internet survey to members of The Union around the world to assess access to these new treatment strategies.DESIGN: A nine-question survey was developed using SurveyMonkey®. The survey was open for participation to all members of The Union registered under the TB Section. Two reminders were sent during each survey. The responses were analyzed taking into account the WHO Region to which the respondent belonged.RESULTS: The 2018 survey showed a global increase in implementation of the shorter (9-month) MDR-TB regimen (from 33% to 56% of respondents, P < 0.001) and an increase in the use of bedaquiline and/or delamanid (from 25% to 41% of respondents, P < 0.001) compared to 2017. There were substantial variations in roll-out between WHO regions.CONCLUSION: These results demonstrate improvement in global implementation of the new treatment strategies over a 1-year period.

Discordant rifampicin susceptibility results are associated with Xpert® MTB/RIF probe B and probe binding delay.

SETTING: Xpert® MTB/RIF is the first-line diagnostic test for Mycobacterium tuberculosis and rifampicin (RIF) resistance in South Africa. OBJECTIVE: To describe the rates of Xpert RIF resistance not confirmed on follow-up testing, as well as the patient and test characteristics associated with discordant results. DESIGN: Retrospective review of patients with isolates showing Xpert RIF resistance. Line-probe assay, phenotypic drug susceptibility testing or repeat Xpert were all considered confirmatory tests of RIF resistance. 'Discordance' was defined as a patient with RIF resistance identified on initial Xpert testing, with a subsequent confirmatory test indicating RIF susceptibility. Associations were analysed using Pearson χ² difference of proportions and modified Poisson regression. RESULTS: RIF discordance occurred in 22/263 subjects and was associated with Xpert probe B, probe binding delay, as opposed to probe dropout, and probe binding delays (ΔCt) of between 4 and 4.9. CONCLUSION: Discordant RIF resistance was common in our cohort and was associated with Xpert probe delay and use of probe B.

Insights into drug-resistant tuberculosis treatment: results of The Union DR-TB Working Group Survey, 2017.

The past 4 years have seen the introduction of new regimens and new drugs to treat multidrug-resistant tuberculosis (MDR-TB). To identify implementation trends over time, the DR-TB Working Group of the International Union Against Tuberculosis and Lung Disease (The Union), in collaboration with RESIST-TB, launched an online survey to Union members around the world. Survey results showed substantial diversity in treatment roll-out: 36% of respondents stated that their country is using the 9-month regimen for MDR-TB treatment; 41% are using bedaquiline and delamanid, but not the 9-month regimen; 28% are using both; and 22% of respondents indicated that their country does not currently offer either of these treatment options. Survey respondents also identified specific challenges to the introduction of shorter MDR-TB regimens and new drugs, including access to rapid diagnosis of fluoroquinolone resistance and case management. The results of this survey are intended to help identify research and implementation gaps while highlighting the importance of global implementation of scalable regimens for the treatment of MDR-TB.

Les quatre dernières années ont vu l'introduction de nouveaux protocoles et de nouveaux médicaments dans le traitement de la tuberculose multirésistante (TB-MDR). Dans le but d'identifier les tendances de la mise en œuvre dans le temps, le groupe de travail sur la TB résistante de l'Union Internationale contre la tuberculose et les maladies respiratoires (L'Union), en collaboration avec RESIST-TB, a lancé une enquête en ligne auprès des membres de l'Union autour du monde. Les résultats de l'enquête ont montré une grande diversité dans le lancement du traitement : 36% des répondants ont affirmé que leur pays utilisait le protocole de 9 mois pour le traitement de la TB-MDR ; 41% utilisent la bédaquiline et le délamanide, mais pas le protocole de 9 mois ; 28% utilisent les deux ; et 22% des répondants ont indiqué que leur pays n'offrait actuellement aucune de ces options de traitement. Les répondants ont également identifié les défis spécifiques à l'introduction de protocoles plus courts et de nouveaux médicaments de TB-MDR, notamment l'accès à un diagnostic rapide de la résistance aux fluoroquinolones et la prise en charge des cas. Les résultats de cette enquête sont destinés à contribuer à identifier les lacunes en matière de recherche et de mise en œuvre, tout en mettant en lumière l'importance de la mise en œuvre mondiale de protocoles évolutifs pour le traitement de la TB-MDR.

En los últimos 4 años ha tenido lugar la introducción de nuevos esquemas terapéuticos y nuevos fármacos para el tratamiento de la tuberculosis multirresistente (TB-MDR). Con el propósito de evaluar las tendencias de su aplicación en el transcurso del tiempo, el grupo de trabajo sobre TB farmacorresistente de la Unión Internacional Contra la Tuberculosis y Enfermedades Respiratorias (La Unión), en colaboración con la iniciativa RESIST-TB, emprendió una encuesta en línea dirigida a los miembros de La Unión en todo el mundo. Los resultados pusieron de manifiesto una gran diversidad del despliegue del tratamiento. El 36% de quienes respondieron afirmaba que en su país se utiliza el esquema de 9 meses para el tratamiento de la TB-MDR; el 41% utiliza bedaquilina y delamanid, pero no el esquema de 9 meses; el 28% utilizan ambos; y el 22% de quienes respondieron indicaba que en su país no se ofrece en la actualidad ninguna de estas opciones terapéuticas. Las respuestas a la encuesta revelan también dificultades específicas con la introducción de los esquemas más cortos de tratamiento de la TB-MDR y con los nuevos medicamentos, entre ellas el acceso al diagnóstico rápido de la resistencia a las fluoroquinolonas y el manejo de los casos. Los resultados de esta encuesta tienen por finalidad contribuir a reconocer las lagunas en la investigación y en la ejecución y al mismo tiempo destacar la importancia de la introducción mundial de esquemas ampliables de tratamiento de la TB-MDR.

Quantifying TB transmission: a systematic review of reproduction number and serial interval estimates for tuberculosis.

Tuberculosis (TB) is the leading global infectious cause of death. Understanding TB transmission is critical to creating policies and monitoring the disease with the end goal of TB elimination. To our knowledge, there has been no systematic review of key transmission parameters for TB. We carried out a systematic review of the published literature to identify studies estimating either of the two key TB transmission parameters: the serial interval (SI) and the reproductive number. We identified five publications that estimated the SI and 56 publications that estimated the reproductive number. The SI estimates from four studies were: 0.57, 1.42, 1.44 and 1.65 years; the fifth paper presented age-specific estimates ranging from 20 to 30 years (for infants <1 year old) to <5 years (for adults). The reproductive number estimates ranged from 0.24 in the Netherlands (during 1933-2007) to 4.3 in China in 2012. We found a limited number of publications and many high TB burden settings were not represented. Certain features of TB dynamics, such as slow transmission, complicated parameter estimation, require novel methods. Additional efforts to estimate these parameters for TB are needed so that we can monitor and evaluate interventions designed to achieve TB elimination.