Reliable enumeration of malaria parasites in thick blood films using digital image analysis

Malaria Journal

Table 2 Comparison of manual and digital counts

Slide	K/Sk	RN	Number of parasites counted per slide		% Discrepancy	Spearman correlation R; p	Wilcoxon test p
			Manual counts	Digital counts
BF3A	2.33	5.20	5022	5071	0.98	0.99; < 0.05	0.15
BF5A	2.59	5.38	4516	4540	0.53	0.98; < 0.05	0.36
BF6A	1.13	4.38	10686	10438	2.32	0.96; < 0.05	< 0.01
BF7A	2.70	5.45	9373	9515	1.51	0.94; < 0.05	0.03
BF8A	5.00	7.02	344	289	15.99	0.56; < 0.05	0.01
BF9A	4.29	6.53	634	619	2.37	0.76; < 0.05	0.40
BF10A	3.98	6.32	1003	870	13.26	0.62; < 0.05	< 0.01
BF13A	3.90	6.27	2446	2158	11.77	0.91; < 0.05	< 0.01
BF18A	2.38	5.24	22477	21956	2.32	0.98; < 0.05	< 0.01
AMI3a	1.41	4.57	424	438	3.30	0.61; < 0.05	0.53
AMI26	4.60	6.74	127	140	10.24	0.24; 0.08	0.53
AMI32	4.95	6.98	5819	6149	5.67	0.91; < 0.05	< 0.01
BF7Ab	2.31	5.19	8059	8251	2.38	0.99; < 0.05	< 0.01
BF8Ab	4.63	6.76	291	277	4.81	0.69; < 0.05	0.08
BF9Ab	4.27	6.52	369	333	9.76	0.85; < 0.05	0.03
BF13Ab	3.18	5.78	1373	1356	1.24	0.88; < 0.05	0.14
BF15A	2.55	5.35	3904	3914	0.26	0.99; < 0.05	0.63
BF16A	1.71	4.78	14265	14273	0.06	0.94; < 0.05	0.03
BF17A	2.21	5.12	6807	6999	2.82	0.86; < 0.05	< 0.01
AMI3b	1.30	4.50	281	272	3.20	0.97; < 0.05	0.33
Total			98220	97858
Mean					4.74

Data are kurtosis/skewness (K/Sk) and resultant factor RN, used to set digital particle counting algorithm for each slide; number of particles per slide counted manually and digitally, and compared by absolute % discrepancy, rank correlation, and signed rank test.

ISSN: 1475-2875