Browsing by Author "Shuma, Brian"

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    Prospective Multi-Site Validation of AI to Detect Tuberculosis and Chest X-Ray Abnormalities.
    (2024-Oct) Kazemzadeh, Sahar; Kiraly, Atilla P.; Nabulsi, Zaid; Sanjase, Nsala; Maimbolwa, Minyoi ; Shuma, Brian; Jamshy, Shahar; Chen, Christina; Agharwal, Arnav; Lau, Charles T.; Sellergren, Andrew; Golden, Daniel; Yu, Jin; Wu, Eric; Matias, Yossi; Chou, Katherine ; Corrado, Greg S.; Shetty, Shravya ; Tse, Daniel; Eswaran, Krish; Liu, Yun; Pilgrim, Rory; Muyoyeta, Monde; Prabhakara, Shruthi
    BACKGROUND: Using artificial intelligence (AI) to interpret chest X-rays (CXRs) could support accessible triage tests for active pulmonary tuberculosis (TB) in resource-constrained settings. METHODS: The performance of two cloud-based CXR AI systems - one to detect TB and the other to detect CXR abnormalities - in a population with a high TB and human immunodeficiency virus (HIV) burden was evaluated. We recruited 1978 adults who had TB symptoms, were close contacts of known TB patients, or were newly diagnosed with HIV at three clinical sites. The TB-detecting AI (TB AI) scores were converted to binary using two thresholds: a high-sensitivity threshold and an exploratory threshold designed to resemble radiologist performance. Ten radiologists reviewed images for signs of TB, blinded to the reference standard. Primary analysis measured AI detection noninferiority to radiologist performance. Secondary analysis evaluated AI detection as compared with the World Health Organization (WHO) targets (90% sensitivity, 70% specificity). Both used an absolute margin of 5%. The abnormality-detecting AI (abnormality AI) was evaluated for noninferiority to a high-sensitivity target suitable for triaging (90% sensitivity, 50% specificity). RESULTS: Of the 1910 patients analyzed, 1827 (96%) had conclusive TB status, of which 649 (36%) were HIV positive and 192 (11%) were TB positive. The TB AI's sensitivity and specificity were 87% and 70%, respectively, at the high-sensitivity threshold and 78% and 82%, respectively, at the balanced threshold. Radiologists' mean sensitivity was 76% and mean specificity was 82%. At the high-sensitivity threshold, the TB AI was noninferior to average radiologist sensitivity (P<0.001) but not to average radiologist specificity (P=0.99) and was higher than the WHO target for specificity but not sensitivity. At the balanced threshold, the TB AI was comparable to radiologists. The abnormality AI's sensitivity and specificity were 97% and 79%, respectively, with both meeting the prespecified targets. CONCLUSIONS: The CXR TB AI was noninferior to radiologists for active pulmonary TB triaging in a population with a high TB and HIV burden. Neither the TB AI nor the radiologists met WHO recommendations for sensitivity in the study population. AI can also be used to detect other CXR abnormalities in the same population.
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    The accuracy of point-of-care C-Reactive Protein as a screening test for tuberculosis in children.
    (2024) Kagujje, Mary; Nyangu, Sarah; Maimbolwa, Minyoi M.; Shuma, Brian; Sanjase, Nsala; Chungu, Chalilwe ; Kerkhoff, Andrew D.; Creswell, Jacob; Muyoyeta, Monde
    Systematic screening for TB in children, especially among those at high risk of TB, can promote early diagnosis and treatment of TB. The World Health Organization (WHO) recently recommended C-Reactive Protein as a TB screening tool in adults and adolescents living with HIV (PLHIV). Thus, we aimed to assess the performance of point-of-care (POC) CRP as a screening tool for TB in children. A cross-sectional study was conducted at 2 primary health care facilities in Lusaka, Zambia between September 2020 -August 2021. Consecutive children (aged 5-14 years) presenting for TB services were enrolled irrespective of TB symptoms. All participants were screened for the presence of TB symptoms and signs, asked about TB contact history, and undertook a POC CRP test, chest X-ray, and sputum Xpert MTB/RIF Ultra test. The accuracy of CRP (≥10 mg/L cutoff) was determined using a microbiological reference standard (MRS) and a composite reference standard (CRS). Of 280 children enrolled and with complete results available, the median age was 10 years (IQR 7-12), 56 (20.0%) were HIV positive, 228 (81.4%) had a positive WHO symptom screen for TB, 62 (22.1%) had a close TB contact, and 79 (28.2%) had a positive CRP POC test. Five (1.8%) participants had confirmed TB, 71 (25.4%) had unconfirmed TB, and 204 (72.3%) had unlikely TB. When the MRS was used, the sensitivity of CRP was 80.0% (95%CI: 28.4-99.5%) and the specificity was 72.7% (95%CI: 67.1-77.9%). When the CRS was used, the sensitivity of CRP was 32.0% (95%CI: 23.3% - 42.5%), while the specificity was 74.0% (95%CI: 67.0% - 80.3%). Using the CRS, there were no statistically significant differences in sensitivity and specificity of CRP in the HIV positive and HIV negative individuals. Among children in Zambia, POC CRP had limited utility as a screening tool for TB. There remains a continued urgent need for better tools and strategies to improve TB detection in children.