Table 1.
Performance characteristics of a newly developed ELISA based on Fasciola circulating antigen detection in sera of 120 parasitologically diagnosed F. gigantica-infected individuals and 80 noninfected individuals
| Parasitological diagnosis | No. of individuals | No. of individuals with FgCA-27 ELISA resulta |
% positivity | |
|---|---|---|---|---|
| Positive | Negative | |||
| F. gigantica infected | TP | FN | ||
| Light infection (<100 EPG) | 76 | 69 | 7 | 90.8 |
| Moderate infection (100–299 EPG) | 33 | 32 | 1 | 96.9 |
| Severe infection (≥300 EPG) | 11 | 11 | 0 | 100 |
| Total | 120 | 112 | 8 | 93.3 |
| Not infected with F. gigantica | FP | TN | ||
| Other parasitic infection | 57 | 3 | 54 | 5.2 |
| No parasitic infection | 23 | 1 | 22 | 4.3 |
| Total | 80 | 4 | 76 | 5.0 |
Abbreviations: TP, true positive (a serum sample from an individual with confirmed Fasciola infection showing a positive result by the ELISA); FP, false positive (a serum sample from an individual with confirmed absence of Fasciola infection showing a positive result by the ELISA); TN, true negative (a serum sample from an individual with confirmed absence of Fasciola infection showing a negative result by the ELISA); FN, false negative (a serum sample from a patient with confirmed Fasciola infection showing a negative result by the ELISA). Sensitivity (%) = TP/(TP + FN) = 112/(112 + 8) × 100% = 93.3%; specificity (%) = TN/(TN + FP) = 76/(76 + 4) × 100% = 95.0%; efficiency of the test (%) = (TP + TN)/total = (112 + 76)/200 × 100% = 94.0%.