Table 5.
Overall performance of microscopy and Optimal-IT in the discrimination of symptomatic malaria cases presenting with low parasitaemia.
| Diagnostic method | Plasmodium species | Sensitivity | Specificity | PPV | NPV |
|---|---|---|---|---|---|
| Optimal-IT® | Plasmodium non falciparum | 76%* | 100% | 100% | 75% |
| P. falciparum | 75%† | 100% | 100% | 97% | |
| Plasmodium sp | 76%* | 100% | 100% | 88% | |
| Microscopy | P. vivax | 58% | 100% | 100% | 88%† |
| P. falciparum | 63% | 100% | 100% | 96% | |
| P. vivax + P. falciparum | 59% | 100% | 100% | 81% |
Values represent data from patients with <500 parasites/μL of blood determined by light microscopy. Nested PCR was considered the gold standard. PPV, positive predictive value; NPV, negative predictive value. The results for the sensitivity, specificity, PPV and NPV obtained for each Plasmodium species were compared between the diagnostic methods using Fisher's exact test. *p < 0.01; †p < 0.05.