Sources of variability in the measurement of Ascaris lumbricoides infection intensity by Kato-Katz and qPCR

Parasites & Vectors

Table 5 Mean and variance calculated from four technical replicate measurements from each of 16 slides

Sample number	qPCR		KK		qPCR	KK	CoV KK/CoV qPCR^a
Sample number	Mean	Variance	Mean	Variance	Coefficient of variation		CoV KK/CoV qPCR^a
1	0.1300	0.00035684	375	10,061	0.15	0.27	2
2	0.0004	0.00000003	8	78	0.46	1.18	3
3	0.0285	0.00000085	116	425	0.03	0.18	5
4	0.0285	0.00000085	117	140	0.03	0.10	3
5	0.0019	0.00000005	3	5	0.12	0.68	6
6	0.0067	0.00000060	76	418	0.12	0.27	2
7	0.1300	0.00035684	313	13,847	0.15	0.38	3
8	0.0149	0.00000174	140	44	0.09	0.05	1
9	0.0011	0.00000004	12	108	0.17	0.88	5
10	0.0149	0.00000174	210	341	0.09	0.09	1
11	0.0606	0.00019056	94	582	0.23	0.26	1
12	0.0634	0.00019056	104	246	0.22	0.15	1
13	0.0634	0.00000766	95	475	0.04	0.23	5
14	0.0634	0.00000766	114	2025	0.04	0.39	9
15	0.0835	0.00002502	123	1294	0.06	0.29	5
16	0.0835	0.00002502	97	1348	0.06	0.38	6

Since some of the KK slides used in this analysis were prepared from the same stool (slides A and B), but each stool was only analyzed once by qPCR, some mean and variance qPCR measurements are shown in duplicate in this chart. The subset of samples used for this analysis is described in Table 2
^a Coefficient of variation (variance divided by mean) of Kato-Katz measurements divided by the coefficient of variation of measurements from the same stool

ISSN: 1756-3305