TY - JOUR
T1 - Field evaluation of the diagnostic performance of EasyScan GO
T2 - A digital malaria microscopy device based on machine-learning
AU - Das, Debashish
AU - Vongpromek, Ranitha
AU - Assawariyathipat, Thanawat
AU - Srinamon, Ketsanee
AU - Kennon, Kalynn
AU - Stepniewska, Kasia
AU - Ghose, Aniruddha
AU - Sayeed, Abdullah Abu
AU - Faiz, M. Abul
AU - Netto, Rebeca Linhares Abreu
AU - Siqueira, Andre
AU - Yerbanga, Serge R.
AU - Ouédraogo, Jean Bosco
AU - Callery, James J.
AU - Peto, Thomas J.
AU - Tripura, Rupam
AU - Koukouikila-Koussounda, Felix
AU - Ntoumi, Francine
AU - Ong’echa, John Michael
AU - Ogutu, Bernhards
AU - Ghimire, Prakash
AU - Marfurt, Jutta
AU - Ley, Benedikt
AU - Seck, Amadou
AU - Ndiaye, Magatte
AU - Moodley, Bhavani
AU - Sun, Lisa Ming
AU - Archasuksan, Laypaw
AU - Proux, Stephane
AU - Nsobya, Sam L.
AU - Rosenthal, Philip J.
AU - Horning, Matthew P.
AU - McGuire, Shawn K.
AU - Mehanian, Courosh
AU - Burkot, Stephen
AU - Delahunt, Charles B.
AU - Bachman, Christine
AU - Price, Ric N.
AU - Dondorp, Arjen M.
AU - Chappuis, François
AU - Guérin, Philippe J.
AU - Dhorda, Mehul
N1 - Funding Information:
The study was funded by the Intellectual Ventures' Global Good Fund. The sub-study sites were funded by the Wellcome Trust of Great Britain (Bangladesh), the Organização Pan-Americana da Saúde and Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brazil), the Bill & Melinda Gates Foundation—OPP1132628 (Cambodia), the Asia Pacific Malaria Elimination Network supported by the Bill & Melinda Gates Foundation, INV-010504 (Nepal), the President’s Malaria Initiative (Senegal) and the South African Medical Research Council Collaborating Centre Grant (South Africa).
Publisher Copyright:
© 2022, The Author(s).
PY - 2022/12
Y1 - 2022/12
N2 - Background: Microscopic examination of Giemsa-stained blood films remains the reference standard for malaria parasite detection and quantification, but is undermined by difficulties in ensuring high-quality manual reading and inter-reader reliability. Automated parasite detection and quantification may address this issue. Methods: A multi-centre, observational study was conducted during 2018 and 2019 at 11 sites to assess the performance of the EasyScan Go, a microscopy device employing machine-learning-based image analysis. Sensitivity, specificity, accuracy of species detection and parasite density estimation were assessed with expert microscopy as the reference. Intra- and inter-device reliability of the device was also evaluated by comparing results from repeat reads on the same and two different devices. This study has been reported in accordance with the Standards for Reporting Diagnostic accuracy studies (STARD) checklist. Results: In total, 2250 Giemsa-stained blood films were prepared and read independently by expert microscopists and the EasyScan Go device. The diagnostic sensitivity of EasyScan Go was 91.1% (95% CI 88.9–92.7), and specificity 75.6% (95% CI 73.1–78.0). With good quality slides sensitivity was similar (89.1%, 95%CI 86.2–91.5), but specificity increased to 85.1% (95%CI 82.6–87.4). Sensitivity increased with parasitaemia rising from 57% at < 200 parasite/µL, to ≥ 90% at > 200–200,000 parasite/µL. Species were identified accurately in 93% of Plasmodium falciparum samples (kappa = 0.76, 95% CI 0.69–0.83), and in 92% of Plasmodium vivax samples (kappa = 0.73, 95% CI 0.66–0.80). Parasite density estimates by the EasyScan Go were within ± 25% of the microscopic reference counts in 23% of slides. Conclusions: The performance of the EasyScan Go in parasite detection and species identification accuracy fulfil WHO-TDR Research Malaria Microscopy competence level 2 criteria. In terms of parasite quantification and false positive rate, it meets the level 4 WHO-TDR Research Malaria Microscopy criteria. All performance parameters were significantly affected by slide quality. Further software improvement is required to improve sensitivity at low parasitaemia and parasite density estimations. Trial registration ClinicalTrials.gov number NCT03512678.
AB - Background: Microscopic examination of Giemsa-stained blood films remains the reference standard for malaria parasite detection and quantification, but is undermined by difficulties in ensuring high-quality manual reading and inter-reader reliability. Automated parasite detection and quantification may address this issue. Methods: A multi-centre, observational study was conducted during 2018 and 2019 at 11 sites to assess the performance of the EasyScan Go, a microscopy device employing machine-learning-based image analysis. Sensitivity, specificity, accuracy of species detection and parasite density estimation were assessed with expert microscopy as the reference. Intra- and inter-device reliability of the device was also evaluated by comparing results from repeat reads on the same and two different devices. This study has been reported in accordance with the Standards for Reporting Diagnostic accuracy studies (STARD) checklist. Results: In total, 2250 Giemsa-stained blood films were prepared and read independently by expert microscopists and the EasyScan Go device. The diagnostic sensitivity of EasyScan Go was 91.1% (95% CI 88.9–92.7), and specificity 75.6% (95% CI 73.1–78.0). With good quality slides sensitivity was similar (89.1%, 95%CI 86.2–91.5), but specificity increased to 85.1% (95%CI 82.6–87.4). Sensitivity increased with parasitaemia rising from 57% at < 200 parasite/µL, to ≥ 90% at > 200–200,000 parasite/µL. Species were identified accurately in 93% of Plasmodium falciparum samples (kappa = 0.76, 95% CI 0.69–0.83), and in 92% of Plasmodium vivax samples (kappa = 0.73, 95% CI 0.66–0.80). Parasite density estimates by the EasyScan Go were within ± 25% of the microscopic reference counts in 23% of slides. Conclusions: The performance of the EasyScan Go in parasite detection and species identification accuracy fulfil WHO-TDR Research Malaria Microscopy competence level 2 criteria. In terms of parasite quantification and false positive rate, it meets the level 4 WHO-TDR Research Malaria Microscopy criteria. All performance parameters were significantly affected by slide quality. Further software improvement is required to improve sensitivity at low parasitaemia and parasite density estimations. Trial registration ClinicalTrials.gov number NCT03512678.
KW - Artificial intelligence
KW - Diagnostic accuracy
KW - Digital microscopy
KW - Light microscopy
KW - Machine-learning
KW - Malaria
UR - http://www.scopus.com/inward/record.url?scp=85128011870&partnerID=8YFLogxK
U2 - 10.1186/s12936-022-04146-1
DO - 10.1186/s12936-022-04146-1
M3 - Article
C2 - 35413904
AN - SCOPUS:85128011870
SN - 1475-2875
VL - 21
SP - 1
EP - 12
JO - Malaria Journal
JF - Malaria Journal
IS - 1
M1 - 122
ER -