Breaking the threshold: Developing multivariable models using computer-aided chest X-ray analysis for tuberculosis triage.

OBJECTIVES: Computer-aided detection (CAD) software packages quantify tuberculosis (TB)-compatible chest X-ray (CXR) abnormality as continuous scores. In practice, a threshold value is selected for binary CXR classification. We assessed the diagnostic accuracy of an alternative approach to applying CAD for TB triage: incorporating CAD scores in multivariable modeling. METHODS: We pooled individual patient data from four studies. Separately, for two commercial CAD, we used logistic regression to model microbiologically confirmed TB. Models included CAD score, study site, age, sex, human immunodeficiency virus status, and prior TB. We compared specificity at target sensitivities ≥90% between the multivariable model and the current threshold-based approach for CAD use. RESULTS: We included 4,733/5,640 (84%) participants with complete covariate data (median age 36 years; 45% female; 22% with prior TB; 22% people living with human immunodeficiency virus). A total of 805 (17%) had TB. Multivariable models demonstrated excellent performance (areas under the receiver operating characteristic curve [95% confidence interval]: software A, 0.91 [0.90-0.93]; software B, 0.92 [0.91-0.93]). Compared with threshold scores, multivariable models increased specificity (e.g., at 90% sensitivity, threshold vs model specificity [95% confidence interval]: software A, 71% [68-74%] vs 75% [74-77%]; software B, 69% [63-75%] vs 75% [74-77%]). CONCLUSION: Using CAD scores in multivariable models outperformed the current practice of CAD-threshold-based CXR classification for TB diagnosis.

Expanding molecular diagnostic coverage for tuberculosis by combining computer-aided chest radiography and sputum specimen pooling: a modeling study from four high-burden countries.

Background: In 2022, fewer than half of persons with tuberculosis (TB) had access to molecular diagnostic tests for TB due to their high costs. Studies have found that the use of artificial intelligence (AI) software for chest X-ray (CXR) interpretation and sputum specimen pooling can each reduce the cost of testing. We modeled the combination of both strategies to estimate potential savings in consumables that could be used to expand access to molecular diagnostics. Methods: We obtained Xpert testing and positivity data segmented into deciles by AI probability scores for TB from the community- and healthcare facility-based active case finding conducted in Bangladesh, Nigeria, Viet Nam, and Zambia. AI scores in the model were based on CAD4TB version 7 (Zambia) and qXR (all other countries). We modeled four ordinal screening and testing approaches involving AI-aided CXR interpretation to indicate individual and pooled testing. Setting a false negative rate of 5%, for each approach we calculated additional and cumulative savings over the baseline of universal Xpert testing, as well as the theoretical expansion in diagnostic coverage. Results: In each country, the optimal screening and testing approach was to use AI to rule out testing in deciles with low AI scores and to guide pooled vs individual testing in persons with moderate and high AI scores, respectively. This approach yielded cumulative savings in Xpert tests over baseline ranging from 50.8% in Zambia to 57.5% in Nigeria and 61.5% in Bangladesh and Viet Nam. Using these savings, diagnostic coverage theoretically could be expanded by 34% to 160% across the different approaches and countries. Conclusions: Using AI software data generated during CXR interpretation to inform a differentiated pooled testing strategy may optimize TB diagnostic test use, and could extend molecular tests to more people who need them. The optimal AI thresholds and pooled testing strategy varied across countries, which suggests that bespoke screening and testing approaches may be needed for differing populations and settings. Supplementary Information: The online version contains supplementary material available at 10.1186/s44263-024-00081-2.

A prospective evaluation of the diagnostic accuracy of the point-of-care VISITECT CD4 Advanced Disease test in seven countries.

BACKGROUND: CD4 measurement is pivotal in the management of advanced HIV disease. VISITECT® CD4 Advanced Disease (AccuBio Limited, Alva, UK; VISITECT) is an instrument-free, point-of-care, semi-quantitative test allowing visual identification of a CD4 ≤200 cells/µl, or >200 cells/µl from finger-prick or venous blood. METHODS: As part of a diagnostic accuracy study of FUJIFILM SILVAMP TB LAM (clinicaltrials.gov: NCT04089423), people living with HIV of ≥18 years old were prospectively recruited in seven countries from outpatient departments if a tuberculosis symptom was present, and from inpatient departments. Participants provided venous blood for CD4 measurement using flow cytometry (reference standard) and finger-prick blood for VISITECT (index text), performed at point-of-care. Sensitivity, specificity, and positive and negative predictive values of VISITECT to determine a CD4 ≤200 cells/µl were evaluated. RESULTS: Among 1604 participants, the median flow cytometry CD4 was 367 (IQR 128-626) cells/µl and 521 (32.5%) had a CD4 ≤200 cells/µl. VISITECT sensitivity was 92.7% (483/521, 95% CI 90.1-94.7%) and specificity was 61.4% (665/1083, 95% CI 58.4-64.3%). For participants with a CD4 between 0-100, 101-200, 201-300, 301-500, and >500 cells/µl, VISITECT misclassified 4.5% (95% CI 2.5-7.2%), 12.5 (95% CI 8.0-18.2%), 74.1% (95% CI 67.0-80.5%), 48.0% (95% CI 42.5-53.6%), and 22.6% (95% CI 19.3-26.3%), respectively. CONCLUSIONS: VISITECT's sensitivity, but not specificity, met the World Health Organization's minimal sensitivity and specificity threshold of 80% for point-of-care CD4 tests. VISITECT's quality needs to be assessed and its accuracy optimized. VISITECT´s utility as CD4 triage test should be investigated.

Reaching for 90:90:90 in Correctional Facilities in South Africa and Zambia: Virtual Cross-Section of Coverage of HIV Testing and Antiretroviral Therapy During Universal Test and Treat Implementation.

BACKGROUND: People in correctional settings are a key population for HIV epidemic control. We sought to demonstrate scale-up of universal test and treat in correctional facilities in South Africa and Zambia through a virtual cross-sectional analysis. METHODS: We used routine data on 2 dates: At the start of universal test and treat implementation (time 1, T1) and 1 year later (time 2, T2). We obtained correctional facility census lists for the selected dates and matched HIV testing and treatment data to generate virtual cross-sections of HIV care continuum indicators. RESULTS: In the South African site, there were 4193 and 3868 people in the facility at times T1 and T2; 43% and 36% were matched with HIV testing or treatment data, respectively. At T1 and T2, respectively, 1803 (43%) and 1386 (36%) had known HIV status, 804 (19%) and 845 (21%) were known to be living with HIV, and 60% and 56% of those with known HIV were receiving antiretroviral therapy (ART). In the Zambian site, there were 1467 and 1366 people in the facility at times T1 and T2; 58% and 92% were matched with HIV testing or treatment data, respectively. At T1 and T2, respectively, 857 (59%) and 1263 (92%) had known HIV status, 277 (19%) and 647 (47%) were known to be living with HIV, and 68% and 68% of those with known HIV were receiving ART. CONCLUSIONS: This virtual cross-sectional analysis identified gaps in HIV testing coverage, and ART initiation that was not clearly demonstrated by prior cohort-based studies.

Diagnostic yield as an important metric for the evaluation of novel tuberculosis tests: rationale and guidance for future research.

Better access to tuberculosis testing is a key priority for fighting tuberculosis, the leading cause of infectious disease deaths in people. Despite the roll-out of molecular WHO-recommended rapid diagnostics to replace sputum smear microscopy over the past decade, a large diagnostic gap remains. Of the estimated 10·6 million people who developed tuberculosis globally in 2022, more than 3·1 million were not diagnosed. An exclusive focus on improving tuberculosis test accuracy alone will not be sufficient to close the diagnostic gap for tuberculosis. Diagnostic yield, which we define as the proportion of people in whom a diagnostic test identifies tuberculosis among all people we attempt to test for tuberculosis, is an important metric not adequately explored. Diagnostic yield is particularly relevant for subpopulations unable to produce sputum such as young children, people living with HIV, and people with subclinical tuberculosis. As more accessible non-sputum specimens (eg, urine, oral swabs, saliva, capillary blood, and breath) are being explored for point-of-care tuberculosis testing, the concept of yield will be of growing importance. Using the example of urine lipoarabinomannan testing, we illustrate how even tests with limited sensitivity can diagnose more people with tuberculosis if they enable increased diagnostic yield. Using tongue swab-based molecular tuberculosis testing as another example, we provide definitions and guidance for the design and conduct of pragmatic studies that assess diagnostic yield. Lastly, we show how diagnostic yield and other important test characteristics, such as cost and implementation feasibility, are essential for increased effective population coverage, which is required for optimal clinical care and transmission impact. We are calling for diagnostic yield to be incorporated into tuberculosis test evaluation processes, including the WHO Grading of Recommendations, Assessment, Development, and Evaluations process, providing a crucial real-life implementation metric that complements traditional accuracy measures.

Prospective multicentre accuracy evaluation of the FUJIFILM SILVAMP TB LAM test for the diagnosis of tuberculosis in people living with HIV demonstrates lot-to-lot variability.

There is an urgent need for rapid, non-sputum point-of-care diagnostics to detect tuberculosis. This prospective trial in seven high tuberculosis burden countries evaluated the diagnostic accuracy of the point-of-care urine-based lipoarabinomannan assay FUJIFILM SILVAMP TB LAM (FujiLAM) among inpatients and outpatients living with HIV. Diagnostic performance of FujiLAM was assessed against a mycobacterial reference standard (sputum culture, blood culture, and Xpert Ultra from urine and sputum at enrollment, and additional sputum culture ≤7 days from enrollment), an extended mycobacterial reference standard (eMRS), and a composite reference standard including clinical evaluation. Of 1637 participants considered for the analysis, 296 (18%) were tuberculosis positive by eMRS. Median age was 40 years, median CD4 cell count was 369 cells/ul, and 52% were female. Overall FujiLAM sensitivity was 54·4% (95% CI: 48·7-60·0), overall specificity was 85·2% (83·2-87·0) against eMRS. Sensitivity and specificity estimates varied between sites, ranging from 26·5% (95% CI: 17·4%-38·0%) to 73·2% (60·4%-83·0%), and 75·0 (65·0%-82·9%) to 96·5 (92·1%-98·5%), respectively. Post-hoc exploratory analysis identified significant variability in the performance of the six FujiLAM lots used in this study. Lot variability limited interpretation of FujiLAM test performance. Although results with the current version of FujiLAM are too variable for clinical decision-making, the lipoarabinomannan biomarker still holds promise for tuberculosis diagnostics. The trial is registered at clinicaltrials.gov (NCT04089423).

The Incidence and Risk Factors for Enterotoxigenic E. coli Diarrheal Disease in Children under Three Years Old in Lusaka, Zambia.

This study aimed to estimate the incidence and risk factors for Enterotoxigenic Escherichia coli (ETEC) diarrhea. This was a prospective cohort study of children recruited in a household census. Children were enrolled if they were 36 months or below. A total of 6828 children were followed up passively for 12 months to detect episodes of ETEC diarrhea. Diarrheal stool samples were tested for ETEC using colony polymerase chain reaction (cPCR). Among the 6828 eligible children enrolled, a total of 1110 presented with at least one episode of diarrhea. The overall incidence of ETEC diarrhea was estimated as 2.47 (95% confidence interval (CI): 2.10-2.92) episodes per 100 child years. Children who were HIV-positive (adjusted Hazard ratio (aHR) = 2.14, 95% CI: 1.14 to 3.99; p = 0.017) and those whose source of drinking water was public tap/borehole/well (aHR = 2.45, 95% CI: 1.48 to 4.06; p < 0.002) were at increased risk of ETEC diarrhea. This study found that children whose mothers have at least senior secondary school education (aHR = 0.49, 95% CI: 0.29 to 0.83; p = 0.008) were at decreased risk of ETEC diarrhea. Our study emphasizes the need for integrated public health strategies focusing on water supply improvement, healthcare for persons living with HIV, and maternal education.

Knowledge, attitudes, and practices towards childhood tuberculosis among healthcare workers at two primary health facilities in Lusaka, Zambia.

BACKGROUND: Zambia is among the 30 high-burden countries for tuberculosis (TB), Human Immunodeficiency Virus (HIV)-associated TB, and multi-drug resistant/rifampicin resistant TB with over 5000 children developing TB every year. However, at least 32% of the estimated children remain undiagnosed. We assessed healthcare workers' (HCWs) knowledge, attitudes, and practices (KAP) towards childhood TB and the factors associated with good KAP towards childhood TB. METHODS: Data was collected at two primary healthcare facilities in Lusaka, Zambia from July to August 2020. Structured questionnaires were administered to HCWs that were selected through stratified random sampling. Descriptive analysis was done to determine KAP. A maximum knowledge, attitude, and practice scores for a participant were 44, 10, and 8 points respectively. The categorization as either "poor" or "good" KAP was determined based on the mean/ median. Logistic regression analysis was performed to assess the associations between participant characteristics and KAP at statistically significant level of 0.05%. RESULTS: Among the 237 respondents, majority were under 30 years old (63.7%) and were female (72.6%). Half of the participants (50.6%) were from the outpatient department (OPD) and antiretroviral therapy (ART) clinic, 109 (46.0) had been working at the facility for less than 1 year, 134 (56.5%) reported no previous training in TB. The median/mean KAP scores were 28 (IQR 24.0-31.0), 7 (IQR = 6.0-8.0) and 5 points (SD = 1.9) respectively. Of the participants, 43.5% (103/237) had good knowledge, 48.1% (114/237) had a good attitude, and 54.4% (129/237) had good practice scores on childhood TB. In the multivariate analysis, clinical officers and individuals with 1-5 years' work experience at the facility had higher odds, 2.61 (95% CI = 1.18-5.80, p = 0.018) and 3.09 (95% CI = 1.69-5.65, p = 0.001) of having good attitude respectively, and medical doctors had 0.17 lower odds (95% CI = 0.18-5.80, p = 0.018) of good childhood TB practice. Other participant characteristics didn't show a significant association with the scores. CONCLUSION: The study found suboptimal levels of knowledge, attitude, and practices regarding childhood TB among HCWs. Targeted programmatic support needs to be provided to address the above gaps.

Engagement of private health care facilities in TB management in Lusaka district of Zambia: lessons learned and achievements.

BACKGROUND: Globally, at least 3 million TB patients are missed every year. In Zambia, the TB treatment coverage increased from 66% in 2020 to 92% in 2022. Involvement of all levels of health care service delivery is critical to finding all the missing TB patients. METHODS: A survey was undertaken in 15 private facilities in Lusaka district of Zambia using a structured tool administered by project team and a district health team member. Data collected during the survey was analysed and results were used to determine the type of TB services that were offered as well as barriers and enablers to TB service provision. This was followed by a set of interventions that included; training and mentorship on active case finding and systematic TB screening, increased diagnostic capacity, provision of national recording and reporting tools and provision of TB medication through linkage with the National TB program (NTP). We report findings from the baseline survey and changes in presumptive TB identification and notification following interventions. RESULTS: Major barriers to TB service delivery were the high cost of TB diagnostic testing and treatment in facilities where services were not supported by the National TB program; the mean cost was 33 (SD 33) and 93 (SD 148) for GeneXpert testing and a full course of treatment respectively. Pre-intervention, presumptive TB identification appeared to increase monthly by 4 (P = 0.000, CI=[3.00-5.00]). The monthly trends of presumptive TB identification during the intervention period increased by 5.32 (P = 0.000, [CI 4.31-6.33. Pre-intervention, the notification of TB appeared to decrease every month by -4.0 (P = 0.114, CI=[-9.00-0.10]) followed by an immediate increase in notifications of 13.94 TB patients (P = 0.001, CI [6.51, 21.36] in the first month on intervention. The monthly trends of notification during the intervention period changed by 0.34 (P = 0.000 [CI 0.19-0.48]). Private facility contribution to TB notification increased from 3 to 7%. CONCLUSION: Engagement and inclusion of private health facilities in TB service provision through a systems strengthening approach can increase contribution to TB notification by private health facilities.

Prevalence of Diarrhoeagenic Escherichia coli among Children Aged between 0-36 Months in Peri-Urban Areas of Lusaka.

Diarrhoea is a major contributor to childhood morbidity and mortality in developing countries, with diarrhoeagenic Escherichia coli being among the top aetiological agents. We sought to investigate the burden and describe the diarrhoeagenic E. coli pathotypes causing diarrhoea among children in peri-urban areas of Lusaka, Zambia. This was a facility-based surveillance study conducted over an 8-month period from 2020 to 2021. Stool samples were collected from children aged 0-3 years presenting with diarrhoea at five peri-urban health facilities in Lusaka. Stool samples were tested for diarrhoeagenic E. coli using the Novodiag bacterial GE+® panel, a platform utilising real-time PCR and microarray technology to detect bacterial pathogens. Of the 590 samples tested, diarrhoeagenic E. coli were detected in 471 (76.1%). The top three pathogens were enteropathogenic E. coli 45.4% (n = 268), enteroaggregative E. coli 39.5% (n = 233), and enterotoxigenic E. coli 29.7% (n = 176). Our results revealed that 50.1% of the diarrhoeagenic E. coli positive samples comprised multiple pathotypes of varying virulence gene combinations. Our study demonstrates a high prevalence of diarrhoeagenic E. coli in childhood diarrhoea and the early exposure (<12 months) of children to enteric pathogens. This calls for the early implementation of preventive interventions for paediatric diarrhoea.

The burden of non-communicable diseases among people living with HIV in Sub-Saharan Africa: a systematic review and meta-analysis.

Background: Non-communicable diseases (NCDs) are increasing among people living with HIV (PLHIV), especially in Sub-Saharan Africa (SSA). We determined the prevalence of NCDs and NCD risk factors among PLHIV in SSA to inform health policy makers. Methods: We conducted a systematic review and meta-analysis on the prevalence of NCDs and risk factors among PLHIV in SSA. We comprehensively searched PubMed/MEDLINE, Scopus, and EBSCOhost (CINAHL) electronic databases for sources published from 2010 to July 2023. We applied the random effects meta-analysis model to pool the results using STATA. The systematic review protocol was registered on PROSPERO (registration number: CRD42021258769). Findings: We included 188 studies from 21 countries in this meta-analysis. Our findings indicate pooled prevalence estimates for hypertension (20.1% [95% CI:17.5-22.7]), depression (30.4% [25.3-35.4]), diabetes (5.4% [4.4-6.4]), cervical cancer (1.5% [0.1-2.9]), chronic respiratory diseases (7.1% [4.0-10.3]), overweight/obesity (32.2% [29.7-34.7]), hypercholesterolemia (21.3% [16.6-26.0]), metabolic syndrome (23.9% [19.5-28.7]), alcohol consumption (21.3% [17.9-24.6]), and smoking (6.4% [5.2-7.7]). Interpretation: People living with HIV have a high prevalence of NCDs and their risk factors including hypertension, depression, overweight/obesity, hypercholesterolemia, metabolic syndrome and alcohol consumption. We recommend strengthening of health systems to allow for improved integration of NCDs and HIV services in public health facilities in SSA. NCD risk factors such as obesity, hypercholesterolemia, and alcohol consumption can be addressed through health promotion campaigns. There is a need for further research on the burden of NCDs among PLHIV in most of SSA. Funding: This study did not receive any funding.

Prioritizing persons deprived of liberty in global guidelines for tuberculosis preventive treatment.

In this Policy Forum piece, Aditya Narayan and colleagues discuss the challenges and opportunities for tuberculosis preventive treatment in carceral settings.

Protein dose-sparing effect of AS01B adjuvant in a randomized preventive HIV vaccine trial of ALVAC-HIV (vCP2438) and adjuvanted bivalent subtype C gp120.

BACKGROUND: HVTN 120 is a phase 1/2a randomized double-blind placebo-controlled HIV vaccine trial that evaluated the safety and immunogenicity of ALVAC-HIV (vCP2438) and MF59- or AS01B-adjuvanted bivalent subtype C gp120 Env protein at two dose levels in healthy HIV-uninfected adults. Trial registration URL https://clinicaltrials.gov/ct2/show/NCT03122223 and registration number NCT03122223. METHODS: Participants received ALVAC-HIV (vCP2438) alone or placebo at months 0 and 1. At months 3 and 6, participants received either placebo, ALVAC-HIV (vCP2438) with 200µg of bivalent subtype C gp120 adjuvanted with MF59 or AS01B, or ALVAC-HIV (vCP2438) with 40µg of bivalent subtype C gp120 adjuvanted with AS01B. Primary outcomes were safety and immune responses. RESULTS: We enrolled 160 participants, 55% females, 18-40 years old (median age 24 years) of whom 150 received vaccine and 10 placebo. Vaccines were generally safe and well tolerated. At months 6.5 and 12, CD4+ T-cell response rates and magnitudes were higher in the AS01B-adjuvanted groups than in the MF59-adjuvanted group. At month 12, HIV-specific Env-gp120 binding antibody response magnitudes in the 40µg gp120/AS01B group were higher than in either of the 200µg gp120 groups. CONCLUSIONS: The 40µg dose gp120/AS01B regimen elicited the highest CD4+ T-cell and binding antibody responses.

Improving measurement of tuberculosis care cascades to enhance people-centred care.

Care cascades represent the proportion of people reaching milestones in care for a disease and are widely used to track progress towards global targets for HIV and other diseases. Despite recent progress in estimating care cascades for tuberculosis (TB) disease, they have not been routinely applied at national and subnational levels, representing a lost opportunity for public health impact. As researchers who have estimated TB care cascades in high-incidence countries (India, Madagascar, Nigeria, Peru, South Africa, and Zambia), we describe the utility of care cascades and identify measurement challenges, including the lack of population-based disease burden data and electronic data capture, the under-reporting of people with TB navigating fragmented and privatised health systems, the heterogeneity of TB tests, and the lack of post-treatment follow-up. We outline an agenda for rectifying these gaps and argue that improving care cascade measurement is crucial to enhancing people-centred care and achieving the End TB goals.

Strategies to increase childhood tuberculosis case detection at the primary health care level: Lessons from an active case finding study in Zambia.

INTRODUCTION: In high TB burden settings, it is estimated that 10-20% of total notifications should be children, however, currently only 6-8% of the total TB notifications in Zambia are children. We assessed whether the implementation of a multicomponent strategy, at primary healthcare facilities, that systematically targets barriers at each step of the childhood TB diagnostic cascade can increase childhood TB case detection. METHODS: We conducted a controlled, interrupted time series analysis to compare childhood TB case notifications before (January 2018-December 2019), and during implementation (January 2020-September 2021) in two intervention and two control Level 1 hospitals in Lusaka, Zambia. At each of the intervention facilities, we implemented a multicomponent strategy constituting: (1) capacity development on childhood TB and interpretation of chest x-ray, (2) TB awareness-raising and demand creation activities, (3) setting up fast track TB services, (4) strengthening of household contact tracing, and (5) improving access to digital chest X-ray for TB screening and Xpert MTB/Rif Ultra for TB diagnosis, through strengthening sample collection in children. FINDINGS: Among 5,150 children < 15 years screened at the two intervention facilities during the study period, 503 (9.8% yield) were diagnosed with TB. Of these, 433 (86.1%) were identified through facility-based activities (10.5% yield) and 70 (13.9%) were identified through household contact tracing (6.9% yield). Overall, 446 children (88.7%) children with TB were clinically diagnosed. Following implementation of the multicomponent strategy, the proportion children contributed to total TB notifications immediately changed by +1.5% (95%CI: -3.5, 6.6) and -4.4% (95%CI: -7.5, 1.4) at the intervention and control sites, respectively (difference 6.0% [95%CI: -0.7, 12.7]), p = 0.08); the proportion of childhood notifications increased 0.9% (95%CI: -0.7, 2.5%) each quarter at the intervention sites relative to pre-implementation trends, while declining 1.2% (-95%CI: -1.8, -0.6) at the control sites (difference 2.1% [95%CI: 0.1, 4.2] per quarter between, p = 0.046); this translated into 352 additional and 85 fewer childhood TB notifications at the intervention and control sites, respectively, compared to the pre-implementation period. CONCLUSION: A standardized package of strategies to improve childhood TB detection at primary healthcare facilities was feasible to implement and was associated with a sustained improvement in childhood TB notifications.

A mixed methods study on men's and women's tuberculosis care journeys in Lusaka, Zambia-Implications for gender-tailored tuberculosis health promotion and case finding strategies.

Men and women with undiagnosed tuberculosis (TB) in high burden countries may have differential factors influencing their healthcare seeking behaviors and access to TB services, which can result in delayed diagnoses and increase TB-related morbidity and mortality. A convergent, parallel, mixed-methods study design was used to explore and evaluate TB care engagement among adults (≥18 years) with newly diagnosed, microbiologically-confirmed TB attending three public health facilities in Lusaka, Zambia. Quantitative structured surveys characterized the TB care pathway (time to initial care-seeking, diagnosis, and treatment initiation) and collected information on factors influencing care engagement. Multinomial multivariable logistic regression was used to determine predicted probabilities of TB health-seeking behaviors and determinants of care engagement. Qualitative in-depth interviews (IDIs; n = 20) were conducted and analyzed using a hybrid approach to identify barriers and facilitators to TB care engagement by gender. Overall, 400 TB patients completed a structured survey, of which 275 (68.8%) and 125 (31.3%) were men and women, respectively. Men were more likely to be unmarried (39.3% and 27.2%), have a higher median daily income (50 and 30 Zambian Kwacha [ZMW]), alcohol use disorder (70.9% [AUDIT-C score ≥4] and 31.2% [AUDIT-C score ≥3]), and a history of smoking (63.3% and 8.8%), while women were more likely to be religious (96.8% and 70.8%) and living with HIV (70.4% and 36.0%). After adjusting for potential confounders, the probability of delayed health-seeking ≥4 weeks after symptom onset did not differ significantly by gender (44.0% and 36.2%, p = 0.14). While the top reasons for delayed healthcare-seeking were largely similar by gender, men were more likely to report initially perceiving their symptoms as not being serious (94.8% and 78.7%, p = 0.032), while women were more likely to report not knowing the symptoms of TB before their diagnosis (89.5% and 74.4%; p = 0.007) and having a prior bad healthcare experience (26.4% and 9.9%; p = 0.036). Notably, women had a higher probability of receiving TB diagnosis ≥2 weeks after initial healthcare seeking (56.5% and 41.0%, p = 0.007). While men and women reported similar acceptability of health-information sources, they emphasized different trusted messengers. Also, men had a higher adjusted probability of stating that no one influenced their health-related decision making (37.9% and 28.3%, p = 0.001). In IDIs, men recommended TB testing sites at convenient community locations, while women endorsed an incentivized, peer-based, case-finding approach. Sensitization and TB testing strategies at bars and churches were highlighted as promising approaches to reach men and women, respectively. This mixed-methods study found important differences between men and women with TB in Zambia. These differences suggest the need for gender-tailored TB health promotion, including addressing harmful alcohol use and smoking among men, and sensitizing HCWs to prolonged delays in TB diagnosis among women, and also using gender-specific approaches as part of community-based, active case-finding strategies to improve TB diagnosis in high burden settings.

Superimposed Pulmonary Tuberculosis (PTB) in a 26-Year-Old Female with No Underlying Co-Morbidities Recovering from COVID-19-Case Report.

Tuberculosis before the COVID-19 pandemic is said to have killed more people globally than any other communicable disease and is ranked the 13th cause of death, according to the WHO. Tuberculosis also still remains highly endemic, especially in LIMCs with a high burden of people living with HIV/AIDS, in which it is the leading cause of mortality. Given the risk factors associated with COVID-19, the cross similarities between tuberculosis and COVID-19 symptoms, and the paucity of data on how both diseases impact each other, there is a need to generate more information on COVID-19-TB co-infection. In this case report, we present a young female patient of reproductive age with no underlying comorbidities recovering from COVID-19, who later presented with pulmonary tuberculosis. It describes the series of investigations performed and treatments given during the follow-up. There is a need for more surveillance for possible COVID-19-TB co-infection cases and further research to understand the impact of COVID-19 on tuberculosis and vice versa, especially in LMICs.

Sensitivity and specificity of CRP and symptom screening as tuberculosis screening tools among HIV-positive and negative outpatients at a primary healthcare facility in Lusaka, Zambia: a prospective cross-sectional study.

OBJECTIVES: To evaluate the performance of point-of-care C-reactive protein (CRP) as a screening tool for tuberculosis (TB) using a threshold of 10 mg/L in both people living with HIV (PLHIV) and HIV-negative individuals and compare it to symptom screening using a composite reference for bacteriological confirmation of TB. METHODS: Prospective cross-sectional study. SETTING: A primary healthcare facility in Lusaka, Zambia. PARTICIPANTS: Consecutive adults (≥18 years) presenting for routine outpatient healthcare were enrolled. Of the 816 individuals approached to participate in the study, 804 eligible consenting adults were enrolled into the study, of which 783 were included in the analysis. PRIMARY OUTCOME MEASURES: Sensitivity, specificity, positive predictive value and negative predictive value (NPV) of CRP and symptom screening. RESULTS: Overall, sensitivity of WHO-recommended four-symptom screen (W4SS) and CRP were 87.2% (80.0-92.5) and 86.6% (79.6-91.8) while specificity was 30.3% (26.7-34.1) and 34.8% (31.2-38.6), respectively. Among PLHIV, sensitivity of W4SS and CRP was 92.2% (81.1-97.8) and 94.8% (85.6-98.9) while specificity was 37.0% (31.3-43.0) and 27.5% (22.4-33.1), respectively. Among those with CD4≥350, the NPV for CRP was 100% (92.9-100). In the HIV negative, sensitivity of W4SS and CRP was 83.8% (73.4-91.3) and 80.3% (69.5-88.5) while specificity was 25.4% (20.9-30.2) and 40.5% (35.3-45.6), respectively. Parallel use of CRP and W4SS yielded a sensitivity and NPV of 100% (93.8-100) and 100% (91.6-100) among PLHIV and 93.3% (85.1-97.8) and 90.0% (78.2-96.7) among the HIV negatives, respectively. CONCLUSION: Sensitivity and specificity of CRP were similar to symptom screening in HIV-positive outpatients. Independent use of CRP offered limited additional benefit in the HIV negative. CRP can independently accurately rule out TB in PLHIV with CD4≥350. Parallel use of CRP and W4SS improves sensitivity irrespective of HIV status and can accurately rule out TB in PLHIV, irrespective of CD4 count.

Scaling up evidence-based approaches to tuberculosis screening in prisons.

People deprived of liberty have among the highest rates of tuberculosis globally. The incidence of tuberculosis is ten times greater than the incidence of tuberculosis in the general population. In 2021, WHO updated its guidance to strongly recommend systematic screening for tuberculosis in prisons and penitentiary systems. Which case-finding strategies should be adopted, and how to effectively implement these strategies in these settings, will be crucial questions facing ministries of health and justice. In this Viewpoint, we review the evidence base for tuberculosis screening and diagnostic strategies in prisons, highlighting promising approaches and knowledge gaps. Drawing upon past experiences of implementing active case-finding and care programmes in settings with a high tuberculosis burden, we discuss challenges and opportunities for improving the tuberculosis diagnosis and treatment cascade in these settings. We argue that improved transparency in reporting of tuberculosis notifications and outcomes in prisons and renewed focus and resourcing from WHO and other stakeholders will be crucial for building the commitment and investments needed from countries to address the continued crisis of tuberculosis in prisons.

The Performance of Computer-Aided Detection Digital Chest X-ray Reading Technologies for Triage of Active Tuberculosis Among Persons With a History of Previous Tuberculosis.

BACKGROUND: Digital chest X-ray (dCXR) computer-aided detection (CAD) technology uses lung shape and texture analysis to determine the probability of tuberculosis (TB). However, many patients with previously treated TB have sequelae, which also distort lung shape and texture. We evaluated the diagnostic performance of 2 CAD systems for triage of active TB in patients with previously treated TB. METHODS: We conducted a retrospective analysis of data from a cross-sectional active TB case finding study. Participants ≥15 years, with ≥1 current TB symptom and complete data on history of previous TB, dCXR, and TB microbiological reference (Xpert MTB/RIF) were included. dCXRs were evaluated using CAD4TB (v.7.0) and qXR (v.3.0). We determined the diagnostic accuracy of both systems, overall and stratified by history of TB, using a single threshold for each system that achieved 90% sensitivity and maximized specificity in the overall population. RESULTS: Of 1884 participants, 452 (24.0%) had a history of previous TB. Prevalence of microbiologically confirmed TB among those with and without history of previous TB was 12.4% and 16.9%, respectively. Using CAD4TB, sensitivity and specificity were 89.3% (95% CI: 78.1-96.0%) and 24.0% (19.9-28.5%) and 90.5% (86.1-93.3%) and 60.3% (57.4-63.0%) among those with and without previous TB, respectively. Using qXR, sensitivity and specificity were 94.6% (95% CI: 85.1-98.9%) and 22.2% (18.2-26.6%) and 89.7% (85.1-93.2%) and 61.8% (58.9-64.5%) among those with and without previous TB, respectively. CONCLUSIONS: The performance of CAD systems as a TB triage tool is decreased among persons previously treated for TB.