Fig 1.
Overview of the different steps, the expert and participating laboratories of the HEMQAS pilot study.
Table 1.
The expert and participating laboratories of the HEMQAS pilot study.
The order of the list does not correspond with the order of the laboratories in Table 5.
Table 2.
Origin and type of worm material used for the HEMQAS panel.
Table 3.
Composition of the HEMQAS stool (ST) and the DNA panel.
Red cells represent samples that are classified as negative for that particular target; green cells represent samples that are classified as positive for the target; orange cells represent samples that are classified as educational for the target.
Table 4.
Overview of the different DNA extraction and NAAT protocols used in the HEMQAS pilot study.
The number between brackets corresponds to the number of laboratories. ITS-1, intergenic transcribed spacer-1; ITS-2, intergenic transcribed spacer-2; 18S rRNA, 18S ribosomal ribonucleic acid; 28S rRNA, 28S ribosomal ribonucleic acid.
Table 5.
The performance of 15 laboratories for the detection of six helminths in stool and DNA.
The numbers in the second row represent the total number of true negatives (TN), true positives (TP) and educational samples (Ed) per target. The laboratories are shown in the left column. The body of the table shows the number of false-positive (FP), false-negative (FN) and educational (Ed) test results per laboratory and per target. Blue cells indicate FP results, red cells indicate FN results, green cells indicate the absence of FP and FN results, black cells indicate that a NAAT has not been performed by a laboratory. The numbers in the blue, red and white cells indicate the number of FP, FN or Ed results, respectively. The ‘All targets’ column, represents per laboratory across all targets the ratio of the totals of FP, FN and educational positives (EP) over the total number of TN, TP and Ed.
Fig 2.
The variation in the reported Cq-values across the different targets and samples.
The Cq-values reported by the different participants for the different targets is shown on the Y-axis. The boxes represent the interquartile range; the lines in the boxes represent the median values; the upper and lower whiskers represent the 95th and the 5th percentile, respectively; and the dots represent outliers. The X-axis represents the different samples of the HEMQAS panel (see Table 3).
Fig 3.
The variation in the reported Cq-values across the different laboratories and targets.
Each dot represents the difference in Cq-value for one sample reported by one laboratory in comparison with the median Cq-values reported by the expert laboratories for that sample. These differences are shown on the Y-axis, with negative values meaning lower Cq-values compared to the median Cq-values reported across the experts, and positive values meaning higher Cq-values. The laboratories, represented by letters, are shown on the X-axis. The number of false-negative and false-positive results reported by each laboratory are shown by means of red stars and blue triangles, respectively. Laboratory M was omitted from this analysis because no positive results were reported by this laboratory.