TY - JOUR
T1 - Performance of a malaria microscopy image analysis slide reading device
AU - Prescott, William R.
AU - Jordan, Robert G.
AU - Grobusch, Martin P.
AU - Chinchilli, Vernon M.
AU - Kleinschmidt, Immo
AU - Borovsky, Joseph
AU - Plaskow, Mark
AU - Torrez, Miguel
AU - Mico, Maximo
AU - Schwabe, Christopher
N1 - Funding Information:
Hydas World Health wishes to gratefully acknowledge the diligent and careful work of its reference readers in establishing the true diagnosis of the samples. This work was sponsored in part by the BIMCP which is funded by a consortium led by Marathon Oil Corporation (Houston, Texas) and the Government of Equatorial Guinea.
PY - 2012
Y1 - 2012
N2 - Abstract. Background: Viewing Plasmodium in Romanovsky-stained blood has long been considered the gold standard for diagnosis and a cornerstone in management of the disease. This method however, requires a subjective evaluation by trained, experienced diagnosticians and establishing proficiency of diagnosis is fraught with many challenges. Reported here is an evaluation of a diagnostic system (a device consisting of a microscope, a scanner, and a computer algorithm) that evaluates scanned images of standard Giemsa-stained slides and reports species and parasitaemia. Methods. The device was challenged with two independent tests: a 55 slide, expert slide reading test the composition of which has been published by the World Health Organization (WHO55 test), and a second test in which slides were made from a sample of consenting subjects participating in a malaria incidence survey conducted in Equatorial Guinea (EGMIS test). These subjects blood was tested by malaria RDT as well as having the blood smear diagnosis unequivocally determined by a worldwide panel of a minimum of six reference microscopists. Only slides with unequivocal microscopic diagnoses were used for the device challenge, n=119. Results: On the WHO55 test, the device scored a Level 4 using the WHO published grading scheme. Broken down by more traditional analysis parameters this result was translated to 89% and 70% sensitivity and specificity, respectively. Species were correctly identified in 61% of the slides and the quantification of parasites fell within acceptable range of the validated parasitaemia in 10% of the cases. On the EGMIS test it scored 100% and 94% sensitivity/specificity, with 64% of the species correct and 45% of the parasitaemia within an acceptable range. A pooled analysis of the 174 slides used for both tests resulted in an overall 92% sensitivity and 90% specificity with 61% species and 19% quantifications correct. Conclusions: In its current manifestation, the device performs at a level comparable to that of many human slide readers. Because its use requires minimal additional equipment and it uses standard stained slides as starting material, its widespread adoption may eliminate the current uncertainty about the quality of microscopic diagnoses worldwide.
AB - Abstract. Background: Viewing Plasmodium in Romanovsky-stained blood has long been considered the gold standard for diagnosis and a cornerstone in management of the disease. This method however, requires a subjective evaluation by trained, experienced diagnosticians and establishing proficiency of diagnosis is fraught with many challenges. Reported here is an evaluation of a diagnostic system (a device consisting of a microscope, a scanner, and a computer algorithm) that evaluates scanned images of standard Giemsa-stained slides and reports species and parasitaemia. Methods. The device was challenged with two independent tests: a 55 slide, expert slide reading test the composition of which has been published by the World Health Organization (WHO55 test), and a second test in which slides were made from a sample of consenting subjects participating in a malaria incidence survey conducted in Equatorial Guinea (EGMIS test). These subjects blood was tested by malaria RDT as well as having the blood smear diagnosis unequivocally determined by a worldwide panel of a minimum of six reference microscopists. Only slides with unequivocal microscopic diagnoses were used for the device challenge, n=119. Results: On the WHO55 test, the device scored a Level 4 using the WHO published grading scheme. Broken down by more traditional analysis parameters this result was translated to 89% and 70% sensitivity and specificity, respectively. Species were correctly identified in 61% of the slides and the quantification of parasites fell within acceptable range of the validated parasitaemia in 10% of the cases. On the EGMIS test it scored 100% and 94% sensitivity/specificity, with 64% of the species correct and 45% of the parasitaemia within an acceptable range. A pooled analysis of the 174 slides used for both tests resulted in an overall 92% sensitivity and 90% specificity with 61% species and 19% quantifications correct. Conclusions: In its current manifestation, the device performs at a level comparable to that of many human slide readers. Because its use requires minimal additional equipment and it uses standard stained slides as starting material, its widespread adoption may eliminate the current uncertainty about the quality of microscopic diagnoses worldwide.
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U2 - 10.1186/1475-2875-11-155
DO - 10.1186/1475-2875-11-155
M3 - Article
C2 - 22559294
AN - SCOPUS:84860531146
SN - 1475-2875
VL - 11
JO - Malaria journal
JF - Malaria journal
M1 - 155
ER -