Table 3.
Sensitivity and specificity of dried blood spots for detection of dengue virus-specific antibody, NS1 antigen and viral RNA in acute dengue patients*
| At enrollment (N = 44) | At discharge (N = 43) | |
|---|---|---|
| IgM | ||
| Plasma positive (of which DBS positive) | 1 (1) | 33 (33) |
| Sensitivity (95% CI) | 100% | 100% |
| Plasma negative (of which DBS negative) | 42 (42) | 8 (6) |
| Specificity (95% CI) | 100% | 75.0% (45.0–100) |
| IgG | ||
| Plasma positive (of which DBS positive) | 1 (1) | 25 (24) |
| Sensitivity (95% CI) | 100% | 96.0% (88.3–100) |
| Plasma negative (of which DBS negative) | 43 (43) | 15 (14) |
| Specificity (95% CI) | 100% | 93.3% (80.7–100%) |
| NS1 | ||
| Plasma positive (of which DBS positive)† | 43 (43) | |
| Sensitivity (95% CI) | 100% | |
| Plasma negative (of which DBS negative) | 0 (0) | |
| Specificity (95% CI) | – | |
| PCR | ||
| Plasma positive (of which DBS positive) | 44 (42) | |
| Sensitivity (95% CI) | 95.5% (89.3–100) | |
| Plasma negative (of which DBS negative) | 0 (0) | |
| Specificity (95% CI) | – | |
*
DBS = dried blood spot; 95% CI = 95% confidence interval.
†
Insufficient DBS sample available for NS1 testing for one participant.
Note: except as noted in (†) where plasma positive and plasma negative do not sum to total number of samples, this is because plasma samples with equivocal results in an assay have been excluded from the calculations for that assay.