Table 1

Comparison of PCR and expert laboratory microscopy for active malaria surveillance.


No. of samples with the following result by PCR (% of total in row)


Expert microscopy resμlt
P. falciparum
P. vivax
P. malariae
P. ovale
Mixed
Negative
Total

P. falciparum
102 (38.4%)
13 (4.9%)
0 (0.0%)
0 (0.0%)
7 (2.7%)
143 (54.0%) a
265
P. vivax
4 (1.0%)
131 (33.9%)
1 (0.3%)
0 (0.0%)
8 (2.1%)
242 (62.7%) b
386
P. malariae
0 (0.0%)
0 (0.0%)
8 (80.0%)
0 (0.0%)
0 (0.0%)
2 (20.0%)
10
Mixed
3 (75.0%)
0 (0.0%)
0 (0.0%)
0 (0.0%)
1 (25.0%)
0 (0.0%)
4
Negative
70 (0.9%)
214 (2.7%)
7 (0.1%)
2 (<0.1%)
18 (0.2%)
7,614 (96.1%)
7,925
Total
179 (2.1%)
358 (4.2%)
16 (0.2%)
2 (<0.1%)
34 (0.40%) c
8,001 (93.1%)
8,590

a 98% (140/143) of microscopy-positive P. falciparum samples that were PCR negative had <250 parasites/μl.

b 99% (239/242) of microscopy-positive P. vivax samples that were PCR negative had <250 parasites/μl.

c Includes the following mixed infections: 28 P. falciparum/P. vivax, 3 P. vivax/P. ovale, 2 P. vivax/P. malariae and 1 P. falciparum/P. malariae.

Coleman et al. Malaria Journal 2006 5:121   doi:10.1186/1475-2875-5-121