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Objective: In Viet Nam, tuberculosis (TB) prevalence surveys revealed that approximately 98% of individuals with pulmonary TB have TB-presumptive abnormalities on chest radiographs, while 32% have no TB symptoms. This prompted the adoption of the "Double X" strategy, which combines chest radiographs and computer-aided detection with GeneXpert testing to screen for and diagnose TB among vulnerable populations. The aim of this study was to describe demographic, clinical and radiographic characteristics of symptomatic and asymptomatic Double X participants and to assess multilabel radiographic abnormalities on chest radiographs, interpreted by computer-aided detection software, as a possible tool for detecting TB-presumptive abnormalities, particularly for subclinical TB., Methods: Double X participants with TB-presumptive chest radiographs and/or TB symptoms and known risks were referred for confirmatory GeneXpert testing. The demographic and clinical characteristics of all Double X participants and the subset with confirmed TB were summarized. Univariate and multivariable logistic regression modelling was used to evaluate associations between participant characteristics and subclinical TB and between computer-aided detection multilabel radiographic abnormalities and TB., Results: From 2020 to 2022, 96 631 participants received chest radiographs, with 67 881 (70.2%) reporting no TB symptoms. Among 1144 individuals with Xpert-confirmed TB, 51.0% were subclinical. Subclinical TB prevalence was higher in older age groups, non-smokers, those previously treated for TB and the northern region. Among 11 computer-aided detection multilabel radiographic abnormalities, fibrosis was associated with higher odds of subclinical TB., Discussion: In Viet Nam, Double X community case finding detected pulmonary TB, including subclinical TB. Computer-aided detection software may have the potential to identify subclinical TB on chest radiographs by classifying multilabel radiographic abnormalities, but further research is needed., Competing Interests: ALI, GLH, TBPN, VHV, THTL, TTTL, VL, VCT, NDBT and THM received salary support from the United States Agency for International Development (USAID) Contract No. AID-440-C-16-00001 and Agreement No. 72044020CA00002. AM and ND were funded by the same USAID Contract and Agreement to conduct statistical analyses for this work. HMP (USAID) participated in the conceptualization of the work and in the manuscript review; USAID as the funding organization was otherwise not involved in the design, conceptualization, analysis or manuscript preparation. VLD, BHN, TTHT, VCN and VNN have no conflicts of interest to declare., ((c) 2024 The authors; licensee World Health Organization.)

OBJECTIVE: To compare two community screening tests for TB: sputum examination using Xpert ® MTB/RIF and chest radiography (CXR). METHOD: Men aged ≥15 years and women aged >45 years living in 96 sub-communes in Ca Mau, Viet Nam, were invited to provide a single sputum specimen that was tested using Xpert. Participants were also invited to attend a nearby location for digital radiography. Participants whose sputum was Xpert MTB-positive or whose CXR was reported as 'consistent with TB´ were requested to provide two further sputum specimens for culture. The sensitivities of the two tests for detecting TB (defined as sputum culture-positive for Mycobacterium tuberculosis ) were compared. RESULTS: There were 72 985 eligible participants, of whom 57 597 (78.9%) participated in Xpert screening, 12 752 (17.5%) had CXR and 11 235 (15.4%) had both tests. We estimated that there were 59 cases of TB, of whom 20 were Xpert MTB-positive (programmatic sensitivity 34.0%) and 47 had CXR reported as 'consistent with TB´ (sensitivity 80.0%, P < 0.0001). CONCLUSION: In community-wide screening for TB, CXR is more sensitive than a single spontaneously expectorated sputum sample tested using Xpert, but it has a substantially lower participation rate.

Objective: To evaluate inter-reader agreement and diagnostic accuracy of chest radiography (CXR) in the diagnosis of tuberculosis (TB) in children with human immunodeficiency virus (HIV) infection., Design: HIV-infected children with clinically suspected TB were enrolled in a prospective study conducted in Burkina Faso, Cambodia, Cameroon and Viet Nam from April 2010 to December 2014. Three readers-a local radiologist, a paediatric pulmonologist and a paediatric radiologist-independently reviewed the CXRs. Inter-reader agreement was then assessed using the κ coefficient. Diagnostic accuracy of CXR was assessed in culture-confirmed cases and controls., Results: A total of 403 children (median age 7.3 years, interquartile range 3.5-9.7; 49.6% males) were enrolled. Inter-reader agreement was as follows: between local radiologist and paediatric pulmonologist, κ = 0.36 (95%CI 0.27-0.45); local radiologist and paediatric radiologist, κ = 0.16 (95%CI 0.08-0.24); and paediatric pulmonologist and paediatric radiologist, κ = 0.30 (95%CI 0.21-0.40). Among 51 cases and 151 controls, after a consensus, CXR had a sensitivity of 71.4% (95%CI 58.8-84.1) and a specificity of 50.0% (95%CI 41.9-58.1). Alveolar opacities and enlarged lymph nodes on CXR had limited specificity for TB (64.7% and 70.2%, respectively). Miliary and/or nodular opacities patterns on CXR were more specific to TB (specificity 94.3%)., Conclusion: CXR showed poor-to-fair inter-reader agreement and limited diagnostic accuracy for TB in HIV-infected children, likely due to comorbidities. Radiological criteria for this specific population require further investigation.

Setting: An Hoa Clinic, a district-level human immunodeficiency virus (HIV) clinic in Ho Chi Minh City, Viet Nam., Objective: To assess the performance of chest radiograph (CXR) in screening for pulmonary tuberculosis (PTB) among HIV-infected individuals and identify misdiagnosed opportunities., Design: This cross-sectional study was conducted in 397 HIV-infected patients consecutively enrolled at the An Hoa Clinic in Ho Chi Minh City, Viet Nam, from August 2009 to June 2010. The performance of CXR in TB screening was assessed based on its sensitivity, specificity, positive likelihood ratio and negative likelihood ratio., Results: Symptom screening alone missed 50% of PTB cases. The combination of CXR and symptom screening yielded an additional 28.6% (8/28) in PTB screening as compared with symptom screening alone, and should be applied routinely, especially in high TB prevalent settings., Conclusion: CXR is a good predictor for PTB even in HIV-infected individuals. The combination of CXR and screening for common TB symptoms considerably improved the sensitivity of detecting active PTB in people living with HIV. If available, routine sputum culture and the World Health Organization-endorsed Xpert(®) MTB/RIF assay should be implemented to achieve a more accurate diagnosis.