Table 2.
Prevalence of P. falciparum in blood donors by diagnostic technique
| Technique | Overall (n = 771) | Ada East (n = 149) | Ashaiman (n = 164) | Ayawaso (n = 155) | Ga South (n = 140) | Ga West (n = 163) | x2 (p value) |
|---|---|---|---|---|---|---|---|
| Microscopy | 59.0 (< 0.01) | ||||||
| Positive | 57 (7.4%) | 16 (10.7%) | 10 (6.1%) | 6 (3.9%) | 13 (9.3%) | 12 (7.4%) | |
| Negative | 714 (92.6%) | 133 (89.3%) | 154 (93.9%) | 149 (96.1%) | 127 (90.7%) | 151 (92.6%) | |
| Rapid diagnostic test | |||||||
| Total RDT+ | 91 (11.8%) | 24 (16.1%) | 14 (8.5%) | 6 (3.9%) | 27 (19.3%) | 20 (12.3%) | 20.0 (< 0.01) |
| PfHRP2+/pLDH+ | 36 (39.6%)a | 9 (37.5%)a | 7 (50.0%)a | 2 (33.3%)a | 10 (37.0%)a | 8 (40.0%)a | |
| PfHRP2+/pLDH− | 52 (57.1%)a | 13 (51.2%)a | 7 (50.0%)a | 4 (66.7%)a | 17 (63.0%)a | 11 (55.0%)a | |
| PfHRP2−/pLDH+ | 3 (3.3%)a | 2 (8.3%)a | 0 (0.0%)a | 0 (0.0%)a | 0 (0.0%)a | 1 (5.0%)a | |
| Molecular assays | |||||||
| crDNA-LAMP | 0.71 (0.399) | ||||||
| Positive | 130 (16.9%) | 36 (24.2%) | 23 (14.0%) | 16 (10.3%) | 28 (20.0%) | 27 (16.6%) | |
| Negative | 641 (84.1%) | 113 (78.5%) | 141 (86.0%) | 139 (89.7%) | 112 (80.0%) | 136 (83.4%) | |
| pDNA-LAMP | 0.14 (0.707) | ||||||
| Positive | 135 (17.5%) | 38 (25.5%) | 23 (14.0%) | 16 (10.3%) | 30 (21.4%) | 28 (17.2%) | |
| Negative | 636 (82.5%) | 111 (74.5%) | 141 (86.0%) | 139 (89.7%) | 110 (78.6%) | 135 (82.8%) | |
| sWGA | |||||||
| Positive | 139 (18.0%) | 37 (24.8%) | 23 (14.0%) | 17 (11.0%) | 31 (22.1%) | 31 (19.0%) | |
| Negative | 632 (82.0%) | 112 (75.2%) | 141 (86.0%) | 138 (89.0%) | 109 (77.9%) | 132 (81.0%) | |
| Sub-microscopic donor parasitaemia | |||||||
| Rapid diagnostic test | 34 (4.4%) | 8 (5.4%) | 4 (2.4%) | 0 (0.0%) | 14 (10.0%) | 8 (4.9%) | 31.70 (< 0.01) |
| crDNA-LAMP | 73 (9.5%) | 20 (13.4%) | 13 (7.9%) | 10 (6.4%) | 15 (10.7%) | 15 (9.2%) | 1.12 (0.290) |
| pDNA-LAMP | 78 (10.1%) | 22 (14.7%) | 13 (7.9%) | 10 (6.4%) | 17 (12.1%) | 16 (9.8%) | 0.22 (0.638) |
| sWGA | 82 (10.6%) | 21 (14.1%) | 13 (7.9%) | 11 (7.0%) | 18 (12.8%) | 19 (11.6%) | |
RDT rapid diagnostic test, PfHRP2 Plasmodium falciparum specific histidine rich protein 2, pLDH Plasmodium specific lactate dehydrogenase, PfHRP2+/pLDH+ both HRP2 and pLDH detected in donor blood, PfHRP2+/pLDH− HRP2 but not pLDH detected in donor blood, PfHRP2−/pLDH+ LDH but not HRP2 detected in donor blood (HRP2 gene deletion), crDNA crude DNA extract, pDNA purified DNA extract, sWGA selective whole genome amplification
aPercentages calculated from the total number of donors tested positive by the RDT
x2 is Chi square goodness of fit test statistic. Significance level was determined at p < 0.05