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Table 1 Data for 13 positive slides (above horizontal line) and for 21 slides with discordant results (below line).

From: Performance of a malaria microscopy image analysis slide reading device

Slide # WHT Result WHT P/ul RDT result # reads agree RR Dx median if pos # discordant reads Alt Dx Reference Reader COMMENTS
63 pf 100 PF 5 pf 47 1 NEG Thick not stained completely; Thin film: incorrectly fixed
143 pf 10,000 PF 7 pf 160 0   microfilariae present; Staining was blue color.
137 pf 1,500 PF 7 pf 596 0   Not good staining, much detritus at edge thick smear.
72 pf 1,600 PF 6 pf 652 0   Thin film incorrectly fixed
61 pf 2,800 PF 6 pf 673 0   no comments
56 Pf/pm 800 MIX 6 pf 675 0   10% ring forms; Plasmodium falciparum
118 pf 571 PF 6 pf 724 0   gametocytes (some rounded up); Thin smear: too thick  + fixation inadequate
44 pf 100 PF 6 pf 1,151 0   Malaria pigment seen. Parasites not well stained. Thick film not well distributed. massive stain deposit and presence of multiple artifacts
68 Pf/pm 8,000 MIX 6 pf 1,916 0   Thick film: not completely stained; Thin film: incorrectly fixed
115 Pf/pm 31,600 MIX 6 pf 34,811 0   beautiful parasites! Slide with crack! Thick smear: irregular distribution; Thin smear: too thick
117 Pf/pm 17,200 MIX 6 pf 54,613 0   beautiful parasites! thin smear: too thick
78 pf 50 PF 4 pf 207 2 pfpo A difficult but interesting slide. It is obviously a mixed infection of P. falciparum and either
P. vivax or P. ovale. Some parasites in the thick film have a pinkish background that I associate with P. ovale. Parasitized rbcs in the thin film lack obvious stippling and are normal in size or only very slightly enlarged. About half of the parasitized rbcs in the thin film are distorted in shape (oblong) and/or have fimbriae that is characteristic of P. ovale. This slide is designed to drive readers crazy. There are many large trophs in the thick film with a pinkish "fried egg" appearance, typical in my experience of P. ovale. There are rings with could be either ovale or falciparum. In the thick film I saw one beautiful P.f. gametocyte (confirming P falciparum) and several large, ameboid trophs in rbc's that were only slightly enlarged. This is obviously a mixed infection of falciparum and, most likely, ovale.
74 Pf/ pm 150 MIX 3 pv 110 4 po A difficult slide for me. It is obviously either P. vivax or P. ovale. The parasites in the thin film lack
obvious stippling and are either normal in size or only very slightly enlarged. About 50% of them however had a distorted "oblong" shape and/or fimbriae that is characteristic of P. ovale. I have called this PO because of the compactness of the trophs and stippling on the thick film but the staining on the thin film does not show the stippling or good morphology; thick film: with air bubble; pigment in WBC
111 NEG   NEG 4 NEG   2 pf Thick smear: irregular distribution hemolysation: staining inadequate; fixation inadequate
131 NEG   NEG 4 NEG   2 pf contaminated with bacteria; many eosiniphils; Thin smear: too thick and grease on the slide
134 NEG   NEG 4 NEG   2 pf Thick smear: irregular distribution; Filaria: Manzonella perstans
135 NEG   NEG 4 NEG   2 pf Thick smear: irregular distribution Filaria: Manzonella perstans;
130 NEG   NEG 4 NEG   2 pf Thick smear: distribution irregularFilaria! Manzonella perstans; grease on the slide
129 NEG   NEG 4 NEG   2 pf Microfilariae of Mansonella perstans; Eosinophils ++thick smear: contaminated (bacteria + dust)
147 pf 3,000 OTRO PLAS 4 NEG   3 pf algal contamination of stain
144 NEG   NEG 5 NEG   2 pf not a good slide - too much precipitate; Two destroyed gamete. Too much precipitate, debris; Fixed edges
133 NEG   NEG 4 NEG   2 pf Thick film: irregular distribution; thin film: too thin
132 NEG   MIX 4 NEG   2 pf Thick smear: contaminated with bacteria and dust; Irregular distribution many eosinophils
128 NEG   NEG 4 NEG   2 pf thick smear: contaminated (bacteria + dust); Thin smear: too thick
116 NEG   NEG 4 NEG   2 pf thin smear: too thick + fixation inadequate
140 NEG   NEG 5 pf 26 2 NEG Not good distribution of WBC in thick smear.
58 NEG   NEG 4 pf 30 2 NEG good staining. Pf; prob neg but bc artifacts and stain deposit single parasites in thick film can’t be ruled out
126 NEG   NEG 3 pf 35 3 NEG Thick smear: some contamination (dust)thin smear: too thick
136 NEG   NEG 3 pf 39 3 NEG Thick smear: irregular distribution contaminated with dust; thin smear: too thick
104 NEG   NEG 3 pf 74 3 NEG no comments
103 NEG   PF 4 pf 83 2 NEG 1x M. perstans microfilaria
43 NEG   NEG 3 pf 95 3 NEG Many dots could be confused as chromatin but were two sizes (big and smaller). Call pf pos but many artifacts
145 pf 1,000 PF 5 pf 111 2 NEG RINGS
142 pf 5,000 PF 5 pf 160 2 NEG Algae present yeasts resemble Pfg
  1. Discordant slides were not considered in the evaluation; coalesced comments from all readers in last column.