Active and passive case-finding in tuberculosis-affected households in Peru: a 10-year prospective cohort study

Estimating the Impact of Tuberculosis Pathways on Transmission-What Is the Gap Left by Passive Case Finding?

Current passive case-finding policies have not resulted in the expected decline in tuberculosis incidence. Recognition of the variety of disease pathways experienced by individuals with tuberculosis highlights how many are not served by the current prevention and care system and how much transmission is missed.

A mixed-methods study on impact of active case finding on pulmonary tuberculosis treatment outcomes in India

BACKGROUND

Tuberculosis (TB) remains a significant public health burden in India, with elimination targets set for 2025. Active case finding (ACF) is crucial for improving TB case detection rates, although conclusive evidence of its association with treatment outcomes is lacking. Our study aims to investigate the impact of ACF on successful TB treatment outcomes among pulmonary TB patients in Gujarat, India, and explore why ACF positively impacts these outcomes.

METHODS

We conducted a retrospective cohort analysis in Gujarat, India, including 1,638 pulmonary TB cases identified through ACF and 80,957 cases through passive case finding (PCF) from January 2019 to December 2020. Generalized logistic mixed-model compared treatment outcomes between the ACF and PCF groups. Additionally, in-depth interviews were conducted with 11 TB program functionaries to explore their perceptions of ACF and its impact on TB treatment outcomes.

RESULTS

Our analysis revealed that patients diagnosed through ACF exhibited 1.4 times higher odds of successful treatment outcomes compared to those identified through PCF. Program functionaries emphasized that ACF enhances case detection rates and enables early detection and prompt treatment initiation. This early intervention facilitates faster sputum conversion and helps reduce the infectious period, thereby improving treatment outcomes. Functionaries highlighted that ACF identifies TB cases that might otherwise be missed, ensuring timely and appropriate treatment.

CONCLUSION

ACF significantly improves TB treatment outcomes in Gujarat, India. The mixed-methods analysis demonstrates a positive association between ACF and successful TB treatment, with early detection and prompt treatment initiation being key factors. Insights from TB program functionaries underscore the importance of ACF in ensuring timely diagnosis and treatment, which are critical for better treatment outcomes. Expanding ACF initiatives, especially among hard-to-reach populations, can further enhance TB control efforts. Future research should focus on optimizing ACF strategies and integrating additional interventions to sustain and improve TB treatment outcomes.

Active Case Finding among Adults using an Individual's Vulnerability Score for Pulmonary Tuberculosis in a Rural Village of Goa: A Cross-sectional Study

Background

"Detect-Treat-Prevent-Build" to achieve tuberculosis (TB)-free India is envisaged in the National Tuberculosis Elimination Program (NTEP). To be able to achieve this, it is important to address the fact that the most vulnerable and hard-to-reach groups need to undertake screening. The present review aimed to examine the vulnerability in connection with TB disparities faced by distinct sub-populations generally viewed as vulnerable and follow these for testing.

Materials and Methods

The community-based cross-sectional study was conducted in the field practice area of sub-center Carambolim in a rural area of Goa for 3 months. The households were visited, and data collected via personal interviews were recorded on the questionnaire study tool. Based on the data, the participants' vulnerability mapping was done per the parameters identified.

Results

Among 223 households, 528 persons were screened for vulnerability. The 47 highly vulnerable participants were advised sputum CBNAAT, of which 9 (19%) tested positive for pulmonary TB, while of the 86 moderately vulnerable participants, 4 (5%) tested positive for pulmonary TB. Among the 34 with symptoms suggestive of TB, 3 (9%) tested positive for pulmonary TB.

Conclusions

The study detected 16 new TB patients from the population and found a higher incidence of pulmonary TB among the vulnerable group with no symptoms of Pulmonary TB. A further state-wide survey is recommended to diagnose such cases.

Analysis on time delay of tuberculosis among adolescents and young adults in Eastern China

Background

Tuberculosis (TB) is recognized as a significant global public health concern. Still, there remains a dearth of comprehensive evaluation regarding the specific indicators and their influencing factors of delay for adolescents and young adults.

Methods

All notified pulmonary TB (PTB) patients in Jiaxing City were collected between 2005 and 2022 from China's TB Information Management System. Logistic regression models were conducted to ascertain the factors that influenced patient and health system delays for PTB cases, respectively. Furthermore, the impact of the COVID-19 pandemic on local delays has been explored.

Results

From January 1, 2005 to December 31, 2022, a total of 5,282 PTB cases were notified in Jiaxing City, including 1,678 adolescents and 3,604 young adults. For patient delay, female (AOR: 1.18, 95%CI: 1.05-1.32), PTB complicated with extra-pulmonary TB (AOR: 1.70, 95% CI: 1.28-2.26), passive case finding (AOR: 1.46, 95% CI: 1.07-1.98) and retreatment (AOR: 1.52, 95% CI: 1.11-2.09) showed a higher risk of delay. For health system delay, minorities (AOR: 0.69, 95% CI: 0.53-0.90) and non-students (AOR: 0.83, 95% CI: 0.71-0.98) experienced a lower delay. Referral (AOR: 1.46, 95% CI: 1.29-1.65) had a higher health system delay compared with clinical consultation. Furthermore, county hospitals (AOR: 1.47, 95% CI: 1.32-1.65) and etiological positive results (AOR: 1.46, 95% CI: 1.30-1.63) were associated with comparatively high odds of patient delay. Contrarily, county hospitals (AOR: 0.88, 95% CI: 0.78-1.00) and etiological positive results (AOR: 0.67, 95% CI: 0.59-0.74) experienced a lower health system delay. Besides, the median of patient delay, health system delay, and total delay during the COVID-19 pandemic were significantly lower than that before.

Conclusion

In general, there has been a noteworthy decline in the notification rate of PTB among adolescents and young adults in Jiaxing City while the declining trend was not obvious in patient delay, health system delay, and total delay, respectively. It also found factors such as gender, case-finding method, and the hospital level might influence the times of seeking health care and diagnosis in health agencies. These findings will provide valuable insights for refining preventive and treatment strategies for TB among adolescents and young adults.

Tuberculosis Case Finding in Kulon Progo District, Yogyakarta, Indonesia: Passive versus Active Case Finding Using Mobile Chest X-ray

Active-case finding (ACF) using chest X-ray is an essential method of finding and diagnosing Tuberculosis (TB) cases that may be missed in Indonesia's routine TB case finding. This study compares active and passive TB case-finding strategies. A retrospective study of TB case notification was conducted. Data between 1 January and 31 December 2021, was used. The population in this study were TB cases notified from Kulon Progo District health facilities, including those found through routine activities or active-case findings. A total of 249 TB cases were diagnosed in Kulon Progo in 2021, and 102 (41%) were bacteriologically confirmed. The TB patients' ages ranged from 0 to 85 years (median 52, IQR 31-61). The majority of cases were male (59%, 147/249) and mostly among people aged 15-59 (61.4%, 153/249). The proportion of clinical TB diagnoses among cases found from active-case findings was 74.7% (68/91) while the proportion among passive-case findings was 50% (79/158). Active-case finding contributed 91 (36.5%) TB cases to the total cases detected in Kulon Progo in 2021. The use of chest X-rays in active-case findings likely contributed to the detection of a higher proportion of clinical TB than in passive-case findings.

Improving TB Case Detection Through Active Case-Finding: Results of Multiple Intervention Strategies in Hard-to-Reach Riverine Areas of Southern Nigeria

BACKGROUND

A major challenge to TB control globally is low case detection, largely due to routine health facility-based passive case-finding employed by national TB control programs. Active case-finding is a risk-population-based screening approach that has been established to be effective in TB control. This intervention aimed to increase TB case detection in hard-to-reach areas in southern Nigeria.

METHODS

Using a descriptive cross-sectional design, we conducted implementation research in 15 hard-to-reach riverine local government areas with historically recognized low TB case notification rates. Individuals with TB symptoms were screened using multiple strategies. Data were collected quarterly over a 4-year period using reporting tools and checklists. Descriptive analysis was done with Microsoft Excel spreadsheet 2019.

RESULTS

A total of 1,089,129 individuals were screened: 16,576 in 2017; 108,102 in 2018; 697,165 in 2019; and 267,286 in 2020. Of those screened, 24,802 (2.3%) were identified as presumptive TB, of which 88.8% were tested and 10% were diagnosed with TB (0.23% of those screened). TB notifications more than doubled, increasing by 183.3% and 137.5% in the initial implementation and scale-up, respectively. On average, 441 individuals needed to be screened to diagnose 1 TB case. The cases, predominantly males (56.1%) and aged 15 years and older (77.4%), comprised 71.9% bacteriologically confirmed drug-sensitive TB, 25.8% clinically diagnosed drug-sensitive TB, and 2.3% drug-resistant cases. Detection sources included community outreach (1,786), health facilities (505), people living with HIV (57), and household contacts of bacteriologically confirmed TB cases (123). Remarkably, 98.1% of diagnosed TB cases commenced treatment.

CONCLUSIONS

We found a significant yield in TB case notifications, more than doubling the baseline figures. Given these successful results, we recommend prioritizing resources to support active case-finding strategies in national programs, especially in hard-to-reach areas with high-risk populations, to address TB more comprehensively.

Mass Tuberculosis Screening Among the Elderly: A Population-Based Study in a Well-Confined, Rural County in Eastern China

BACKGROUND

Mass tuberculosis (TB) screening has been recommended in certain high-risk populations. However, population-based screening interventions have rarely been implemented. Whether mass screening improves health equity is unknown.

METHODS

We implemented a mass TB screening intervention among elderly persons (>60 years old) in Lanxi County, China. Standardized questionnaires, physical examinations, and chest radiographs (CXRs) were administered to all participants. Systematic testing with computed tomography, smear, culture, or Xpert was performed among persons with an abnormal CXR. We assessed TB prevalence per 100 000 persons and constructed multivariable regression models among subgroups that were and were not screened. Medical insurance was categorized as participation in either a basic program with limited coverage or a more comprehensive coverage program.

RESULTS

In total, 49 339 individuals (32% of the elderly population in Lanxi) participated in the screening. One hundred fifteen screened persons were diagnosed with TB (233 cases per 100 000 persons), significantly higher than persons not screened (168 cases among 103 979 person-years; prevalence-to-case notification ratio, 1.44 [95% confidence interval {CI}, 1.14-1.83]). This increase was largely driven by diagnosis of asymptomatic disease during mass screening (n = 57 [50% of participants with TB]). Participants with basic medical insurance were much more likely to be diagnosed through mass screening than by passive detection (adjusted odds ratio, 4.52 [95% CI, 1.35-21.28]).

CONCLUSIONS

In a population-based, mass TB screening intervention encompassing >30% of the elderly population in a county in rural China, case finding was 44% higher than background detection, driven by diagnosis of TB without recognized symptoms. Importantly, mass screening identified TB in people with limited healthcare options who were less likely to be found through background case detection.

Facilitators and barriers to tuberculosis active case findings in low- and middle-income countries: a systematic review of qualitative research

BACKGROUND

Tuberculosis (TB) is an ancient infection and a major public health problem in many low- and middle-income countries (LMICs). Active case finding (ACF) programs have been established to effectively reduce TB in endemic global communities. However, there is little information about the evidence-based benefits of active case finding at both the individual and community levels. Accurately identifying the facilitators and barriers to TB-ACF provides information that can be used in planning and design as the world aims to end the global TB epidemic by 2035. Therefore, this study aimed to identify the facilitators and barriers to tuberculosis ACF in LMICs.

METHODS

A systematic search was performed using recognized databases such as PubMed, Google Scholar, SCOPUS, HINARI, and other reference databases. Relevant studies that assessed or reported the ACF of TB conducted in LMICs were included in this study. The Joanna Briggs Institute's (JBI) Critical Appraisal Tool was used to assess the quality of the selected studies. The Statement of Enhancing Transparency in Reporting the Synthesis of Qualitative Research (ENTREQ) was used to strengthen the protocol for this systematic review. The Confidence of Evidence Review Quality (CERQual) approach was also used to assess the reliability of the review findings.

RESULTS

From 228 search results, a total of 23 studies were included in the final review. Tuberculosis ACF results were generated under two main themes: barriers and facilitators in LMICs, and two sub-themes of the barriers (healthcare-related and non-healthcare-related barriers). Finally, barriers to active TB case finding were found to be related to (1) the healthcare workers' experience, knowledge, and skills in detecting TB-ACF, (2) distance and time; (3) availability and workload of ACF healthcare workers; (4) barriers related to a lack of resources such as diagnostic equipment, reagents, and consumables at TB-ACF; (5) the stigma associated with TB-ACF detection; (6) the lack of training of existing and new healthcare professionals to detect TB-ACF; (7) communication strategies and language limitations associated with TB ACF; and (8) poor or no community awareness of tuberculosis. Stigma was the most patient-related obstacle to detecting active TB cases in LMICs.

CONCLUSION

This review found that surveillance, monitoring, health worker training, integration into health systems, and long-term funding of health facilities were key to the sustainability of ACF in LMICs. Understanding the elimination of the identified barriers is critical to ensuring a maximum tuberculosis control strategy through ACF.

Comparing Additionality of Tuberculosis Cases Using GeneXpert or Smear-Based Active TB Case-Finding Strategies among Social Contacts of Index Cases in Nepal

This study compares the yield and additionality of community-based active tuberculosis (TB) active case-finding strategies using either smear microscopy or GeneXpert as the TB diagnostic test. Active case-finding strategies screened social contacts of index cases and high-risk groups in four districts of Nepal in July 2017-2019. Two districts (Chitwan and Dhanusha) applied GeneXpert testing and two districts (Makwanpur and Mahotarri) used smear microscopy. Two control districts implemented standard national TB program activities. Districts implementing GeneXpert testing screened 23,657 people for TB, tested 17,114 and diagnosed 764 TB cases, producing a yield of 4.5%. Districts implementing smear microscopy screened 19,961 people for TB, tested 13,285 and diagnosed 437 cases, producing a yield of 3.3%. The screening numbers required were 31 for GeneXpert and 45.7 for smear districts. The test numbers required were 22.4 and 30.4 for GeneXpert and smear. Using the TB REACH additionality method, social contact tracing for TB through GeneXpert testing contributed to a 20% (3958/3322) increase in district-level TB notifications, smear microscopy 12.4% (3146/2798), and -0.5% (2553/2566) for control districts. Therefore, social contact tracing of TB index cases using GeneXpert testing should be implemented throughout Nepal within the TB FREE initiative to close the notification gap and accelerate progress toward END TB strategy targets.

Global, regional, and national estimates of tuberculosis incidence and case detection among incarcerated individuals from 2000 to 2019: a systematic analysis

BACKGROUND

People who are incarcerated are at high risk of developing tuberculosis. We aimed to estimate the annual global, regional, and national incidence of tuberculosis among incarcerated populations from 2000 to 2019.

METHODS

We collected and aggregated data for tuberculosis incidence and prevalence estimates among incarcerated individuals in published and unpublished literature, annual tuberculosis notifications among incarcerated individuals at the country level, and the annual number of incarcerated individuals at the country level. We developed a joint hierarchical Bayesian meta-regression framework to simultaneously model tuberculosis incidence, notifications, and prevalence from 2000 to 2019. Using this model, we estimated trends in absolute tuberculosis incidence and notifications, the incidence and notification rates, and the case detection ratio by year, country, region, and globally.

FINDINGS

In 2019, we estimated a total of 125 105 (95% credible interval [CrI] 93 736-165 318) incident tuberculosis cases among incarcerated individuals globally. The estimated incidence rate per 100 000 person-years overall was 1148 (95% CrI 860-1517) but varied greatly by WHO region, from 793 (95% CrI 430-1342) in the Eastern Mediterranean region to 2242 (1515-3216) in the African region. Global incidence per 100 000 person-years between 2000 and 2012 among incarcerated individuals decreased from 1884 (95% CrI 1394-2616) to 1205 (910-1615); however, from 2013 onwards, tuberculosis incidence per 100 000 person-years was stable, from 1183 (95% CrI 876-1596) in 2013 to 1148 (860-1517) in 2019. In 2019, the global case detection ratio was estimated to be 53% (95% CrI 42-64), the lowest over the study period.

INTERPRETATION

Our estimates suggest a high tuberculosis incidence rate among incarcerated individuals globally with large gaps in tuberculosis case detection. Tuberculosis in incarcerated populations must be addressed with interventions specifically tailored to improve diagnoses and prevent transmission as a part of the broader global tuberculosis control effort.

FUNDING

National Institutes of Health.

Declining incidence rate of tuberculosis among close contacts in five years post-exposure: a systematic review and meta-analysis

BACKGROUND

Individuals in close contact with active pulmonary tuberculosis (TB) patients showed a high risk of recent infection and, once infected, higher risk of developing active TB in the following years post-exposure. But the peak time of active disease onset is unclear. This study aims to estimate post exposure TB incidence risk among close contacts to provide reference for clinical and public health strategies.

METHODS

We searched PubMed, Web of Science, and EMBASE for articles published until December 1, 2022. The incidence rates were quantitatively summarized by means of meta-analysis using the random-effect model.

RESULTS

Of the 5616 studies, 31 studies included in our analysis. For baseline close contacts results, the summarized prevalence of Mycobacterium tuberculosis (MTB) infection and active TB was found to be 46.30% (95% CI: 37.18%-55.41%) and 2.68% (95% CI: 2.02%-3.35%), respectively. During the follow-up, the 1-year, 2-year and 5-year cumulative incidence of TB in close contacts were 2.15% (95% CI: 1.51%-2.80%), 1.21% (95% CI: 0.93%-1.49%) and 1.11% (95% CI: 0.64%-1.58%), respectively. Individuals with a positive result of MTB infection testing at baseline showed significantly higher cumulative TB incidence as compared to those negatives (3.80% vs. 0.82%, p < 0.001).

CONCLUSIONS

Individuals with close contact to active pulmonary TB patients are bearing significant risk of developing active TB, particularly within the first-year post-exposure. Population with recent infections should be an important priority for active case finding and preventive intervention worldwide.

Factors Associated with Tuberculosis Mortality in Manjung District, Perak, Malaysia

Background

Tuberculosis (TB) is a communicable disease which contributes to a major cause of ill health. Worldwide, it is one of the leading causes of death from a single infectious agent.

Objectives

The study aimed to describe the epidemiology and factors associated with TB mortality in Manjung district, Perak, Malaysia.

Methods

All confirmed TB cases from 2015 to 2020 registered in Manjung district under Sistem Maklumat Tibi (MyTB) were included. Factors associated with TB mortality were analysed by using simple and multiple logistic regression analysis.

Results

A total of 742 TB cases were included in the analysis, from which 121 cases (16.3%) died before completing their treatment. The highest death was reported in 2020 (25.7%) and the lowest in 2019 (12.9%). From multiple logistic regression analysis, age 45 years old-64 years old (adjusted OR = 3.62; 95% CI: 1.38, 9.54), > 65 years old (adjusted OR = 8.67; 95% CI: 3.17, 23.74), non-Malaysian (adjusted OR = 5.18; 95% CI: 2.04, 13.14), cases notified by government hospitals (adjusted OR = 6.78; 95% CI: 3.04, 15.09), HIV-positive status (adjusted OR = 8.60; 95% CI: 3.58, 20.67) and HIV testing not offered/unknown (adjusted OR = 2.58; 95% CI: 1.18, 5.62) were significantly associated with TB mortality.

Conclusion

This study found that TB patients who were 45 years old and above, positive HIV, late diagnosis and are foreigners had a higher risk for TB mortality. Early diagnosis, optimised screening and close monitoring should be practised to reduce TB mortality.

Quantifying Mycobacterium tuberculosis Transmission Dynamics Across Global Settings: A Systematic Analysis

The degree to which individual heterogeneity in the production of secondary cases ("superspreading") affects tuberculosis (TB) transmission has not been systematically studied. We searched for population-based or surveillance studies in which whole genome sequencing was used to estimate TB transmission and in which the size distributions of putative TB transmission clusters were enumerated. We fitted cluster-size-distribution data to a negative binomial branching process model to jointly infer the transmission parameters $R$ (the reproduction number) and the dispersion parameter, $k$, which quantifies the propensity of superspreading in a population (generally, lower values of $k$ ($<1.0$) suggest increased heterogeneity). Of 4,796 citations identified in our initial search, 9 studies from 8 global settings met the inclusion criteria (n = 5 studies of all TB; n = 4 studies of drug-resistant TB). Estimated $R$ values (range, 0.10-0.73) were below 1.0, consistent with declining epidemics in the included settings; estimated $k$ values were well below 1.0 (range, 0.02-0.48), indicating the presence of substantial individual-level heterogeneity in transmission across all settings. We estimated that a minority of cases (range, 2%-31%) drive the majority (80%) of ongoing TB transmission at the population level. Identifying sources of heterogeneity and accounting for them in TB control may have a considerable impact on mitigating TB transmission.

Possible sex difference in latent tuberculosis infection risk among close tuberculosis contacts

OBJECTIVES

More men than women develop and die of tuberculosis (TB). Fewer data exist on sex differences in latent TB infection (LTBI). We assessed for potential sex differences in LTBI acquisition among close TB contacts.

METHODS

Regional Prospective Observational Research for TB-Brazil is an observational multi-center cohort of individuals with culture-confirmed pulmonary TB and their close contacts. Participants were enrolled from five sites in Brazil from June 2015 - June 2019. Close contacts were followed for 24 months after enrollment, with LTBI defined as a positive interferon-γ release assay (IGRA; QuantiFERON 3rd or 4th generation) at baseline or 6 months. We performed univariate, bivariate, and multivariable logistic regression and propensity-score weighted models to assess odds ratios (OR) and 95% confidence intervals (CI) for LTBI acquisition by birth sex among close contacts.

RESULTS

Of 1093, 504 (46%) female close contacts were IGRA positive compared to 295 of 745 (40%) men. The unadjusted OR for IGRA positivity among women vs men was 1.31 (95% CI: 1.08-1.58). Bivariate adjustments yielded ORs in women vs men ranging from 1.19 to 1.33 (P-value range: <0.01-0.07). Multivariable regression and weighted models yielded similar ORs in women vs men, of 1.14 (95% CI: 0.92-1.41) and 1.15 (95% CI: 0.94-1.40), respectively.

CONCLUSION

The point estimate for LTBI among close TB contacts in Brazil was higher in women, though less pronounced in multivariable models. If the sex difference in LTBI is confirmed in additional settings, studies of possible underlying differences in socio-behavioral factors or TB pathogenesis are warranted.

Factors influencing the implementation of TB screening among PLHIV in selected HIV clinics in Ghana: a qualitative study

Background

Decreasing the burden of Tuberculosis (TB) among PLHIV through TB screening is an effective intervention recommended by the World Health Organization (WHO). However, after over a decade of implementation in Ghana, the intervention does not realize the expected outcomes. It is also not well understood whether this lack of success is due to implementation barriers. Our study, therefore, sought to examine the factors influencing the implementation of the intervention among people living with HIV (PLHIV) attending HIV clinics at district hospitals in Ghana.

Methods

This was a qualitative study conducted from 6th to 31 May 2019 in three regions of Ghana. We conducted 17 in-depth interviews (IDIs – comprising two regional, six districts and nine facility TB/HIV coordinators) and eight focus group discussions (FGD – consisting of a total of 65 participants) with HIV care providers. The Consolidated Framework for Implementation Research (CFIR) guided the design of interview guides, data collection and analysis. All responses were digitally audio-recorded and transcribed verbatim for coding and analysis using the Framework Approach. Participants consented to the interview and recording.

Results

The main barriers to TB screening relate to the low commitment of the implementers to screen for TB and limited facility infrastructure for the screening activities. Facilitators of TB screening include (1) ease in TB screening, (2) good communication and referral channels, (3) effective goals and feedback mechanisms, (4) health workers recognizing the need for the intervention and (5) the role of chemical sellers.

Conclusions

Key barriers and facilitators to the intervention are revealed. The study has shown that there is a need to increase HIV care providers and institutional commitment towards TB screening interventions. In addition, cost issues need to be assessed as they are drivers of sustainability. Our study also advances the field of implementation science through CFIR to better understand the factors influencing the implementation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-08295-6.

Discordant results of Xpert MTB/Rif assay and BACTEC MGIT 960 liquid culture to detect Mycobacterium tuberculosis in community screening in Vietnam

BACKGROUND

Xpert MTB/Rif, a molecular test to detect tuberculosis (TB), has been proven to have high sensitivity and specificity when compared with liquid culture in clinical settings. However, little is known about its performance in community TB screening.

METHODS

In Vietnam, a national TB prevalence survey was conducted in 2017. Survey participants who screened positive by chest X-ray, cough symptoms and/or recent history of tuberculosis were requested to provide at least two sputum samples that were tested for Mycobacterium tuberculosis by Xpert MTB/Rif G4 (Xpert) and BACTEC MGIT960 culture (MGIT).

RESULTS

There were 4,649 eligible participants provided both samples for testing. Among them, 236 (5.1%) participants tested positive for TB by Xpert, 244 (5.3%) tested positive by MGIT and 317 tested positive by at least one test; 163 (51.4%) had discordant test results. Of the positive Xpert, 162 (68.6%) showed a low or very low bacterial load. In multivariate logistic regression comparing discordant with Xpert-MGIT concordant positive results, discordant Xpert-positive results occurred more often among participants who had low sputum bacterial load, male sex, a history of TB treatment, or night sweats. The associated factors were male sex, abnormal chest X-ray and having night sweats when the logistic model was against those with both Xpert and MGIT negative.

CONCLUSIONS

We found high rates of discordance in the performance of Xpert and MGIT for community-based TB case finding. In situations where the majority of TB cases are expected to have a low bacterial load, multiple diagnostic tests and/or multiple samples are required to reach sufficient sensitivity.

Supporting tuberculosis program in active contact tracing: a case study from Pakistan

Tuberculosis (TB) is on the rise in Pakistan and there could be multiple reasons including poverty, difficulty in access to TB treatment services, non-compliance with treatment, social stigma etc. According to the TB program managers, limited treatment and testing sites for tuberculosis and lack of trained human resources play a major role in compromising TB management. A major lacuna in the TB control program is the absence of active contact tracing strategy. This is essential for a disease where positive cases are known to be able to infect a further 10‒15 individuals in a year. Tackling tuberculosis in Pakistan has been beleaguered by funding challenges and other systems’ bottlenecks such as lack of skilled human resources and insufficient supply of medicines, despite the fact that disease burden is one of the highest in the world. Although it is a notifiable disease, active case finding, contact tracing and reporting is notoriously low throughout the country. Access to diagnostics and treatment facilities has been limited and stigma attached to the disease remains deeply entrenched among the communities. Researchers have shown that enhanced and active approaches to contact investigation effectively identifies additional patients with TB among household contacts at a relatively modest cost. USAID’s Integrated Health Systems Strengthening and Service Delivery Activity extended support to the Health Departments of Sindh and Khyber Pakhtunkhwa provinces. In collaboration with the two provincial TB programs, community based active contact tracing was conducted on 17,696 individuals, based on the index cases. Among the contacts traced, 243 cases were diagnosed as drug sensitive or drug resistant TB. Awareness sessions were conducted to sensitize people on the various aspects of disease and importance of getting tested. The project also supported establishing three satellite Programmatic Management of Drug Resistant Tuberculosis (PMDT) sites for drug resistant TB treatment, enhancing the programs’ diagnostic and testing capacity.

A Cluster-based Method to Quantify Individual Heterogeneity in Tuberculosis Transmission

BACKGROUND

Recent evidence suggests transmission of Mycobacterium tuberculosis (Mtb) may be characterized by extreme individual heterogeneity in secondary cases (i.e., few cases account for the majority of transmission). Such heterogeneity implies outbreaks are rarer but more extensive and has profound implications in infectious disease control. However, discrete person-to-person transmission events in tuberculosis (TB) are often unobserved, precluding our ability to directly quantify individual heterogeneity in TB epidemiology.

METHODS

We used a modified negative binomial branching process model to quantify the extent of individual heterogeneity using only observed transmission cluster size distribution data (i.e., the simple sum of all cases in a transmission chain) without knowledge of individual-level transmission events. The negative binomial parameter k quantifies the extent of individual heterogeneity (generally, indicates extensive heterogeneity, and as transmission becomes more homogenous). We validated the robustness of the inference procedure considering common limitations affecting cluster size data. Finally, we demonstrate the epidemiologic utility of this method by applying it to aggregate US molecular surveillance data from the US Centers for Disease Control and Prevention.

RESULTS

The cluster-based method reliably inferred k using TB transmission cluster data despite a high degree of bias introduced into the model. We found that the TB transmission in the United States was characterized by a high propensity for extensive outbreaks (; 95% confidence interval = 0.09, 0.10).

CONCLUSIONS

The proposed method can accurately quantify critical parameters that govern TB transmission using simple, more easily obtainable cluster data to improve our understanding of TB epidemiology.

Methods and Approaches for Buruli Ulcer Surveillance in Africa: Lessons Learnt and Future Directions

Over 95% of the global burden of Buruli ulcer disease (BU) caused by Mycobacterium ulcerans occurs in equatorial Africa. National and sub-national programs have implemented various approaches to improve detection and reporting of incident cases over recent decades. Regional incidence rates are currently in decline; however, surveillance targets outlined in 2012 by WHO have been missed and detection bias may contribute to these trends. In light of the new 2030 NTD roadmap and disease-specific targets, BU programs are required to strengthen case detection and begin a transition towards integration with other skin-NTDs. This transition comes with new opportunities to enhance existing BU surveillance systems and develop novel approaches for implementation and evaluation.In this review, we present a breakdown and assessment of the methods and approaches that have been the pillars of BU surveillance systems in Africa: (1) Passive case detection, (2) Data systems, (3) Clinical training, (4) Active case finding, (5) Burden estimation, and (6) Laboratory confirmation pathways. We discuss successes, challenges, and relevant case studies before highlighting opportunities for future development and evaluation including novel data collection tools, risk-based surveillance, and integrated skin-NTD surveillance. We draw on both experience and available literature to critically evaluate methods of BU surveillance in Africa and highlight new approaches to help achieve 2030 roadmap targets.

The circuits of healthcare: Understanding healthcare seeking behaviour-A qualitative study with tuberculosis patients in Lisbon, Portugal

BACKGROUND

Understanding health delivery service from a patient´s perspective, including factors influencing healthcare seeking behaviour, is crucial when treating diseases, particularly infectious ones, like tuberculosis. This study aims to trace and contextualise the trajectories patients pursued towards diagnosis and treatment, while discussing key factors associated with treatment delays. Tuberculosis patients' pathways may serve as indicator of the difficulties the more vulnerable sections of society experience in obtaining adequate care.

METHODS

We conducted 27 semi-structured interviews with tuberculosis patients attending a treatment centre in a suburban area of Lisbon. We invited nationals and migrant patients in active treatment to participate by sharing their illness experiences since the onset of symptoms until the present. The Health Belief Model was used as a reference framework to consolidate the qualitative findings.

RESULTS

By inductive analysis of all interviews, we categorised participants' healthcare seeking behaviour into 4 main types, related to the time participants took to actively search for healthcare (patient delay) and time the health system spent to diagnose and initiate treatment (health system delay). Each type of healthcare seeking behaviour identified (inhibited, timely, prolonged, and absent) expressed a mindset influencing the way participants sought healthcare. The emergency room was the main entry point where diagnostic care cascade was initiated. Primary Health Care was underused by participants.

CONCLUSIONS

The findings support that healthcare seeking behaviour is not homogeneous and influences diagnostic delays. If diagnostic delays are to be reduced, the identification of behavioural patterns should be considered when designing measures to improve health services' delivery. Healthcare professionals should be sensitised and perform continuous capacity development training to deal with patients´ needs. Inhibited and prolonged healthcare seeking behaviour contributes significantly to diagnostic delays. These behaviours should be detected and reverted. Timely responses, from patients and the healthcare system, should be promoted.

The impact of active case finding on transmission dynamics of tuberculosis: A modelling study

Background

In the last decade, active case finding (ACF) strategies for tuberculosis (TB) have been implemented in many diverse settings, with some showing large increases in case detection and reporting at the sub-national level. There have also been several studies which seek to provide evidence for the benefits of ACF to individuals and communities in the broader context. However, there remains no quantification of the impact of ACF with regards to reducing the burden of transmission. We sought to address this knowledge gap and quantify the potential impact of active case finding on reducing transmission of TB at the national scale and further, to determine the intensification of intervention efforts required to bring the reproduction number (R₀) below 1 for TB.

Methods

We adopt a dynamic transmission model that incorporates heterogeneity in risk to TB to assess the impact of an ACF programme (IMPACT TB) on reducing TB incidence in Vietnam and Nepal. We fit the models to country-level incidence data using a Bayesian Markov Chain Monte Carlo approach. We assess the impact of ACF using a parameter in our model, which we term the treatment success rate. Using programmatic data, we estimate how much this parameter has increased as a result of IMPACT TB in the implementation districts of Vietnam and Nepal and quantify additional efforts needed to eliminate transmission of TB in these countries by 2035.

Results

Extending the IMPACT TB programme to national coverage would lead to moderate decreases in TB incidence and would not be enough to interrupt transmission by 2035. Decreasing transmission sufficiently to bring the reproduction number (R0) below 1, would require a further intensification of current efforts, even at the sub-national level.

Conclusions

Active case finding programmes are effective in reducing TB in the short term. However, interruption of transmission in high-burden countries, like Vietnam and Nepal, will require comprehensive incremental efforts. Complementary measures to reduce progression from infection to disease, and reactivation of latent infection, are needed to meet the WHO End TB incidence targets.

Adapting active case-finding for TB during the COVID-19 pandemic in Yogyakarta, Indonesia

The COVID-19 pandemic and response measures, including lockdowns and the reorientation of health services, have disrupted essential health services for other diseases, including TB, HIV and malaria. For TB, reductions in case detection due to the COVID-19 pandemic are projected to result in increased TB transmission, morbidity and mortality. Active case-finding (ACF) for TB using community-based approaches is a potential strategy to offset reductions in TB detection by obviating the need for patients to seek care at a health facility. A number of approaches can be used to conduct TB ACF safely and screen designated target populations while managing the risks of SARS-CoV-2 transmission for staff, individuals and the community. We present a framework of options for and experience of adapting TB ACF services in response to the challenges of COVID-19 in our programme in Yogyakarta, Indonesia. Key changes have included revised prioritisation of target populations focusing on household contacts, reducing case-finding throughput, implementation of additional infection control measures and precautions, and integration of COVID-19 screening among those being screened for TB. Our approach could inform other programmes seeking to adapt TB ACF services to mitigate the negative impact of COVID-19 on TB case detection.

How to reduce household costs for people with tuberculosis: a longitudinal costing survey in Nepal

The aim of this study was to compare costs and socio-economic impact of tuberculosis (TB) for patients diagnosed through active (ACF) and passive case finding (PCF) in Nepal. A longitudinal costing survey was conducted in four districts of Nepal from April 2018 to October 2019. Costs were collected using the WHO TB Patient Costs Survey at three time points: intensive phase of treatment, continuation phase of treatment and at treatment completion. Direct and indirect costs and socio-economic impact (poverty headcount, employment status and coping strategies) were evaluated throughout the treatment. Prevalence of catastrophic costs was estimated using the WHO threshold. Logistic regression and generalized estimating equation were used to evaluate risk of incurring high costs, catastrophic costs and socio-economic impact of TB over time. A total of 111 ACF and 110 PCF patients were included. ACF patients were more likely to have no education (75% vs 57%, P = 0.006) and informal employment (42% vs 24%, P = 0.005) Compared with the PCF group, ACF patients incurred lower costs during the pretreatment period (mean total cost: US$55 vs US$87, P < 0.001) and during the pretreatment plus treatment periods (mean total direct costs: US$72 vs US$101, P < 0.001). Socio-economic impact was severe for both groups throughout the whole treatment, with 32% of households incurring catastrophic costs. Catastrophic costs were associated with 'no education' status [odds ratio = 2.53(95% confidence interval = 1.16-5.50)]. There is a severe and sustained socio-economic impact of TB on affected households in Nepal. The community-based ACF approach mitigated costs and reached the most vulnerable patients. Alongside ACF, social protection policies must be extended to achieve the zero catastrophic costs milestone of the End TB strategy.

Evaluation of a serum-based antigen test for tuberculosis in HIV-exposed infants: a diagnostic accuracy study

BACKGROUND

Non-sputum methods are urgently needed to improve tuberculosis diagnosis and treatment monitoring in children. This study evaluated the ability of a serum assay quantifying a species-specific peptide of the Mycobacterium tuberculosis CFP-10 virulence factor via nanotechnology and matrix-assisted laser desorption ionization time-of-flight mass spectrometry to diagnose tuberculosis in HIV-infected and HIV-uninfected infants.

METHODS

Serum CFP-10 peptide signal was blinded evaluated in cryopreserved sera of 519 BCG-immunized, HIV-exposed infants (284 HIV-infected, 235 HIV-uninfected) from a multi-center randomized placebo-controlled isoniazid prophylaxis trial conducted in southern Africa between 2004 and 2008, who were followed up to 192 weeks for Mtb infection and TB. Children were classified as confirmed, unconfirmed, or unlikely tuberculosis cases using 2015 NIH diagnostic criteria for pediatric TB.

RESULTS

In HIV-infected infants, CFP-10 signal had 100% sensitivity for confirmed TB (5/5, 95% CI, 47.8-100) and 83.7% sensitivity for unconfirmed TB (36/43, 95% CI 69.3-93.2), with 93.1% specificity (203/218, 95% CI 88.9-96.1). In HIV-uninfected infants, CFP-10 signal detected the single confirmed TB case and 75.0% of unconfirmed TB cases (15/20; 95% CI 50.9-91.3), with 96.2% specificity (177/184, 95% CI, 92.3-98.5). Serum CFP-10 achieved 77% diagnostic sensitivity for confirmed and unconfirmed TB (13/17, 95% CI, 50-93%) at ≤ 24 weeks pre-diagnosis, and both CFP-10-positivity and concentration declined following anti-TB therapy initiation.

CONCLUSIONS

Serum CFP-10 signal exhibited high diagnostic sensitivity and specificity for tuberculosis in HIV-infected and HIV-uninfected infants and potential utility for early TB detection and monitoring of anti-TB treatment responses.

Whole Blood Mycobacterial Growth Assays for Assessing Human Tuberculosis Susceptibility: A Systematic Review and Meta-Analysis

Background

Whole blood mycobacterial growth assays (WBMGA) quantify mycobacterial growth in fresh blood samples and may have potential for assessing tuberculosis vaccines and identifying individuals at risk of tuberculosis. We evaluated the evidence for the underlying assumption that in vitro WBMGA results can predict in vivo tuberculosis susceptibility.

Methods

A systematic search was done for studies assessing associations between WBMGA results and tuberculosis susceptibility. Meta-analyses were performed for eligible studies by calculating population-weighted averages.

Results

No studies directly assessed whether WBMGA results predicted tuberculosis susceptibility. 15 studies assessed associations between WBMGA results and proven correlates of tuberculosis susceptibility, which we divided in two categories. Firstly, WBMGA associations with factors believed to reduce tuberculosis susceptibility were statistically significant in all eight studies of: BCG vaccination; vitamin D supplementation; altitude; and HIV-negativity/therapy. Secondly, WBMGA associations with probable correlates of tuberculosis susceptibility were statistically significant in three studies of tuberculosis disease, in a parasitism study and in two of the five studies of latent tuberculosis infection. Meta-analyses for associations between WBMGA results and BCG vaccination, tuberculosis infection, tuberculosis disease and HIV infection revealed consistent effects. There was considerable methodological heterogeneity.

Conclusions

The study results generally showed significant associations between WBMGA results and correlates of tuberculosis susceptibility. However, no study directly assessed whether WBMGA results predicted actual susceptibility to tuberculosis infection or disease. We recommend optimization and standardization of WBMGA methodology and prospective studies to determine whether WBMGA predict susceptibility to tuberculosis disease.

Infectious disease surveillance system descriptors: proposal for a comprehensive set

To tailor a surveillance system to its objectives and to evaluate its fitness for purpose, an accurate description of its structural elements is essential. Existing recommendations for setting up a system seldom offer a comprehensive list of all surveillance elements to be considered. Moreover, there is sometimes confusion in the way terms describing these elements are interpreted. The objective of this paper is to propose a comprehensive set of surveillance system descriptors that can delineate the important elements and clarify the meaning of the terms used. We identified 20 descriptors that we classified in five categories: (i) surveillance scheme; (ii) population and cases; (iii) supplementary data; (iv) information flow; and (v) period of time. We tried to make the definitions of these descriptors as clear and simple as possible to avoid confusion or misinterpretation of the terms used. The relative importance of each element may vary depending on the objectives of the surveillance scheme. Surveillance descriptors should be reviewed periodically to document changes and to assess if the system continues to be fit for purpose. Together with the minimum requirements for variables and the planned outputs for disseminating the data, the surveillance descriptors can be used to define surveillance standards.

Case finding strategies under National Tuberculosis Elimination Programme (NTEP)

Case finding, an important parameter in fight against Tuberculosis (TB) has always remained a challenge despite advances in diagnostic modalities, access to health care and administrative commitment. We are still far from reaching the goals so set as per End TB Strategy and National Strategic Plan 2017–2025, and case finding is of paramount importance for achieving the said targets.

This article, after identifying the obstacles faced in case finding, explores the various case finding strategies in the perspective of diagnostics, feasibility, resource utilization and current recommendations. Need for prioritization of case finding in different settings with involvement and active participation of one and all has been discussed. Role of health education in an individual, general public and health care worker in the context of case finding has been highlighted. Research areas to strengthen case finding have been enumerated. The review concludes by bringing out the need for heightened efforts for case finding in TB as the resources are significantly diverted as the world is facing the corona virus disease 2019 (COVID-19) pandemic.

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Early case finding and prompt treatment is very important for eliminating Tuberculosis but has always remained a challenge.

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Ongoing passive case finding needs to be strictly complemented with active case finding especially in vulnerable population.

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Efforts for case finding in TB should not be neglected despite the present corona virus disease 2019 (COVID-19) pandemic.

Envisioning a learning surveillance system for tuberculosis

Surveillance is critical for interrupting transmission of global epidemics. Research has highlighted gaps in the surveillance for tuberculosis that range from failure to collect real-time data to lack of standardization of data for informed decision-making at different levels of the health system. Our research aims to advance conceptual and methodological foundations for the development of a learning surveillance system for Tuberculosis, that involves systematic collection, analysis, interpretation, and feedback of outcome-specific data. It would concurrently involve the health care delivery system, public health laboratory, and epidemiologists. For our study, we systemically framed the cyber environment of TB surveillance as an ontology of the learning surveillance system. We validated the ontology by binary coding of dimensions and elements of the ontology with the metadata from an existing surveillance platform—GPMS TB Transportal. Results show GPMS TB Transportal collects a critical range of data for active case investigation and presumptive case screening for identifying and detecting confirmed TB cases. It is therefore targeted at assisting the Active Case Finding program. Building on the results, we demonstrate enhanced surveillance strategies for GPMS that are enumerated as pathways in the ontology. Our analysis reveals the scope for embedding learning surveillance pathways for digital applications in Direct Benefit Transfer, and Drug Resistance Treatment in National TB Elimination Programme in India. We discuss the possibilities of developing the transportal into a multi-level computer-aided decision support system for TB, using the innumerable pathways encapsulated in the ontology.

Towards elimination of childhood and adolescent tuberculosis in the Netherlands: an epidemiological time-series analysis of national surveillance data

BACKGROUND

Tuberculosis (TB) in children and adolescents is a sentinel event for ongoing transmission. In the Netherlands, epidemiological characteristics of childhood and adolescent TB have not been fully evaluated. Therefore, we aimed to assess TB epidemiology within this population to provide guidance for TB elimination.

METHODS

A retrospective time-series analysis using national surveillance data from 1993-2018 was performed in children (aged <15 years) and adolescents (aged 15-19 years) with TB. Poisson regression models offset with log-population size were used to estimate notification rates and rate ratios. Trends in notification rates were estimated using average annual percentage changes (AAPC) based on the segmented linear regression analysis.

RESULTS

Among 3899 children and adolescents with TB notified during 1993-2018, 2418 (62%) were foreign-born (725 (41.3%) out of 1755 children and 1693 (78.9%) out of 2144 adolescents). The overall notification rate in children was 2.3 per 100 000 person-years, declining steadily during the study period (AAPC -10.9%, 95% CI -12.6--9.1). In adolescents, the overall notification rate was 8.4 per 100 000 person-years, strongly increasing during 1993-2001 and 2012-2018. Compared to Dutch-born children and adolescents, substantially higher notification rates were observed among African-born children and adolescents (116.8 and 316.6 per 100 000 person-years, respectively). Additionally, an increasing trend was observed in African-born adolescents (AAPC 18.5%, 95% CI 11.9-25.5). Among the foreign-born population, those from countries in the horn of Africa contributed most to the TB caseload.

CONCLUSION

TB notification rate among children was low and constantly declining across different demographic groups. However, heterogeneities were shown in adolescents, with an increasing trend in the foreign-born, particularly those from Africa.

Role of community health workers in improving cost efficiency in an active case finding tuberculosis programme: an operational research study from rural Bihar, India

OBJECTIVES

Cost-efficient active case finding (ACF) approaches are needed for their large-scale adoption in national tuberculosis (TB) programmes. Our aim was to assess if community health workers' (CHW) knowledge about families' health status can improve the cost efficiency of the ACF programme without adversely affecting the delivery of other health services for which they are responsible.

DESIGN

Quasi-experimental design.

INTERVENTIONS

We evaluated an ACF programme in the Samastipur district in Bihar, India, between July 2017 and June 2018. CHWs called Accredited Social Health Activists generated referrals of individuals at risk of TB and conducted symptom-based screening to identify patients with presumptive TB. They also helped them undergo testing and provided treatment support for confirmed TB cases.

PRIMARY AND SECONDARY OUTCOME MEASURES

We compared the notification rate from the intervention region with that from a control region in the same district with similar characteristics. We analysed operational data to calculate the cost per TB case diagnosed. We used routine programmatic data from the public health system to estimate the impact on other services provided by CHWs.

FINDINGS

CHWs identified 9895 patients with presumptive TB. Of these, 5864 patients were tested for TB, and 1236 were confirmed as TB cases. Annual public case notification rate increased sharply in the intervention region from 45.8 to 105.8 per 100 000 population, whereas it decreased from 50.7 to 45.3 in the control region. There was no practically or statistically significant impact on other output indicators of the CHWs, such as institutional deliveries (-0.04%). The overall cost of the intervention was about US$134 per diagnosed case. Main cost drivers were human resources, and commodities (drugs and diagnostics), which contributed 37.4% and 32.5% of the cost, respectively.

CONCLUSIONS

ACF programmes that use existing CHWs in the health system are feasible, cost efficient and do not adversely affect other healthcare services delivered by CHWs.

Tuberculosis in migrants - screening, surveillance and ethics

Tuberculosis (TB) is the leading infectious cause of human mortality and is responsible for nearly 2 million deaths every year. It is often regarded as a 'silent killer' because it predominantly affects the poor and marginalized, and disease outbreaks occur in 'slow motion' compared to Ebola or coronavirus 2 (COVID-19). In low incidence countries, TB is predominantly an imported disease and TB control in migrants is pivotal for countries to progress towards TB elimination in accordance with the World Health Organisations (WHO's) End TB strategy. This review provides a brief overview of the different screening approaches and surveillance processes that are in place in low TB incidence countries. It also includes a detailed discussion of the ethical issues related to TB screening of migrants in these settings and the different interests that need to be balanced. Given recognition that a holistic approach that recognizes and respects basic human rights is required to end TB, the review considers the complexities that require consideration in low-incidence countries that are aiming for TB elimination.

What Constitutes Health Care Seeking Pathway of TB Patients: A Qualitative Study in Rural Bangladesh

Given the targeted 4–5% annual reduction of tuberculosis (TB) cure cases to reach the “End TB Strategy” by 2020 milestone globally set by WHO, exploration of TB health seeking behavior is warranted for insightful understanding. This qualitative study aims to provide an account of the social, cultural, and socioeconomic breadth of TB cases in Bangladesh. We carried out a total of 32 In-depth Interviews (IDIs) and 16 Key Informant Interviews (KIIs) in both rural and urban areas of Bangladesh. We covered both BRAC [a multinational Non-governmental Organization (NGO)] and non-BRAC (other NGOs) TB program coverage areas to get an insight. We used purposive sampling strategy and initially followed “snowball sampling technique” to identify TB patients. Neuman’s three-phase coding system was adopted to analyze the qualitative data. Underestimation of TB knowledge and lack of awareness among the TB patients along with the opinions from their family members played key roles on their TB health seeking behavior. Quick decision on the treatment issue was observed once the diagnosis was confirmed; however, difficulties were in accepting the diseases. Nevertheless, individual beliefs, intrinsic ideologies, financial abilities, and cultural and social beliefs on TB were closely inter-connected with the “social perception” of TB that eventually influenced the care seeking pathways of TB patients in various ways. Individual and community level public health interventions could increase early diagnosis; therefore, reduce recurrent TB.

COVID-19, tuberculosis and poverty: preventing a perfect storm

The coronavirus disease 2019 (COVID-19) pandemic is likely to be the defining global health crisis of our generation. As the United Nations Development Programme highlighted in their recent call to action, the impact of this pandemic will extend beyond the immediate medical consequences to have far-reaching and long-lasting social and economic impacts, threatening to disproportionately affect poorer people in poorer countries [1]. Income losses are anticipated to exceed USD 220 billion in developing countries, where many people live day-to-day without access to social protection, and food security is precarious [1]. Strikingly, a recent United Nations study suggested that the social and economic consequences of the COVID-19 pandemic could increase the number of people living in poverty by as much as half a billion, with the majority of these newly poor people living in Africa, South-East Asia, and Central and South America [2].

The global health community must learn from COVID-19 and take action now on tuberculosis and its social determinants, potentially saving millions from a preventable and curable diseasehttps://bit.ly/2LLgLgA

Yield of Systematic Longitudinal Screening of Household Contacts of Pre-Extensively Drug Resistant (PreXDR) and Extensively Drug Resistant (XDR) Tuberculosis Patients in Mumbai, India

While risk of tuberculosis (TB) is high among household contacts (HHCs) of pre-extensively drug resistant (pre-XDR) TB and XDR-TB, data on yield of systematic longitudinal screening are lacking. We aim to describe the yield of systematic longitudinal TB contact tracing among HHCs of patients with pre-XDR-TB and XDR-TB. At the Médecins Sans Frontières (MSF) clinic, Mumbai, India a cohort comprising 518 HHCs of 109 pre-XDR and XDR index cases was enrolled between January 2016 and June 2018. Regular HHC follow-ups were done till one year post treatment of index cases. Of 518 HHCs, 23 had TB (21 on TB treatment and two newly diagnosed) at the time of first visit. Of the rest, 19% HHCs had no follow-ups. Fourteen (3.5%) TB cases were identified among 400 HHCs; incidence rate: 2072/100,000 person-years (95% CI: 1227-3499). The overall yield of household contact tracing was 3% (16/518). Of 14 who were diagnosed with TB during follow-up, six had drug susceptible TB (DSTB); six had pre-XDR-TB and one had XDR-TB. Five of fourteen cases had resistance patterns concordant with their index case. In view of the high incidence of TB among HHCs of pre-XDR and XDR-TB cases, follow-up of HHCs for at least the duration of index cases' treatment should be considered.

Mobilising community networks for early identification of tuberculosis and treatment initiation in Cambodia: an evaluation of a seed-and-recruit model

Background and objectives

The effects of active case finding (ACF) models that mobilise community networks for early identification and treatment of tuberculosis (TB) remain unknown. We investigated and compared the effect of community-based ACF using a seed-and-recruit model with one-off roving ACF and passive case finding (PCF) on the time to treatment initiation and identification of bacteriologically confirmed TB.

Methods

In this retrospective cohort study conducted in 12 operational districts in Cambodia, we assessed relationships between ACF models and: 1) the time to treatment initiation using Cox proportional hazards regression; and 2) the identification of bacteriologically confirmed TB using modified Poisson regression with robust sandwich variance.

Results

We included 728 adults with TB, of whom 36% were identified via the community-based ACF using a seed-and-recruit model. We found community-based ACF using a seed-and-recruit model was associated with shorter delay to treatment initiation compared to one-off roving ACF (hazard ratio 0.81, 95% CI 0.68-0.96). Compared to one-off roving ACF and PCF, community-based ACF using a seed-and-recruit model was 45% (prevalence ratio (PR) 1.45, 95% CI 1.19-1.78) and 39% (PR 1.39, 95% CI 0.99-1.94) more likely to find and detect bacteriologically confirmed TB, respectively.

Conclusion

Mobilising community networks to find TB cases was associated with early initiation of TB treatment in Cambodia. This approach was more likely to find bacteriologically confirmed TB cases, contributing to the reduction of risk of transmission within the community.

A household-level score to predict the risk of tuberculosis among contacts of patients with tuberculosis: a derivation and external validation prospective cohort study

BACKGROUND

The epidemiological impact and cost-effectiveness of social protection and biomedical interventions for tuberculosis-affected households might be improved by risk stratification. We therefore derived and externally validated a household-level risk score to predict tuberculosis among contacts of patients with tuberculosis.

METHODS

In this prospective cohort study, we recruited tuberculosis-affected households from 15 desert shanty towns in Ventanilla and 17 urban communities in Callao, Lima, Peru. Tuberculosis-affected households included index patients with a new diagnosis of tuberculosis and their contacts who reported being in the same house as the index patient for more than 6 h per week in the 2 weeks preceding index patient diagnosis. Tuberculosis-affected households were not included if the index patient had no eligible contacts or lived alone. We followed contacts until 2018 and defined household tuberculosis, the primary outcome, as any contact having any form of tuberculosis within 3 years. We used logistic regression to identify characteristics of index patients, contacts, and households that were predictive of household tuberculosis, and used these to derive and externally validate a household-level score.

FINDINGS

Between Dec 12, 2007, and Dec 31, 2015, 16 505 contacts from 3 301 households in Ventanilla were included in a derivation cohort. During the 3-year follow-up, tuberculosis occurred in contacts of index patients in 430 (13%, 95% CI 12-14) households. Index patient predictors were pulmonary tuberculosis and sputum smear grade, age, and the maximum number of hours any contact had spent with the index patient while they had any cough. Household predictors were drug use, schooling of the female head of a household, and lower food spending. Contact predictors were if any of the contacts were children, number of lower-weight (body-mass index [BMI] <20·0 kg/m2) adult contacts, number of normal-weight (BMI 20·0-24·9 kg/m2) adult contacts, and number of past or present household members who previously had tuberculosis. In this derivation cohort, the score c statistic was 0·77 and the risk of household tuberculosis in the highest scoring quintile was 31% (95% CI 25-38; 65 of 211) versus 2% (95% CI 0-4; four of 231) in the lowest scoring quintile. We externally validated the risk score in a cohort of 4248 contacts from 924 households in Callao recruited between April 23, 2014, and Dec 31, 2015. During follow-up, tuberculosis occurred in contacts of index patients in 120 (13%, 95% CI 11-15) households. The score c statistic in this cohort was 0·75 and the risk of household tuberculosis in the highest scoring quintile was 28% (95% CI 21-36; 43 of 154) versus 1% (95% CI 0-5; two of 148) in the lowest scoring quintile. The highest-scoring third of households captured around 70% of all tuberculosis among contacts. A simplified risk score including only five variables performed similarly, with only a small reduction in performance.

INTERPRETATION

This externally validated score will enable comprehensive biosocial, household-level interventions to be targeted to tuberculosis-affected households that are most likely to benefit.

FUNDING

Wellcome Trust, Medical Research Council, Department of Health and Social Care, Department for International Development, Joint Global Health Trials consortium, Bill & Melinda Gates Foundation, Innovation for Health and Development.