Table 7.
Diagnostic tests for WNV
| Test | Target | Se | Sp | Matrix | Reference | Notes |
|---|---|---|---|---|---|---|
| NS1‐antigen protein microarray | Antibodies | 95% | 100% | Serum | Cleton et al. (in press) | Differential diagnosis of flavivirus infections in horses |
| Real‐time RT‐PCR | Antigen | From 1.5 to 15 copies per reaction | 100% | Viral strains, human samples (cerebrospinal fluid, biopsies, serum and plasma) and mosquito pools | Vázquez et al. (2016) | Specificity evaluated using viral RNA from a panel of different flaviviruses and other encephalitic viruses belonging to several viral families |
| Real‐time RT‐PCR | Antigen | 80 genome copies | 100% | Viral strains Lineages 1 and 2 | Faggioni et al. (2014) | Specificity evaluated using TBE, Usutu, Dengue 1, Dengue 4, YF, JEV |
| SYBR Green I‐based real‐time RT‐PCR | Antigen | 20 copies | 100% | Human serum/plasma | Kumar et al. (2014) | Specificity evaluated using DEN‐1–4, JEV, YFV, SLEV |
| Antigen capture ELISA | Antigen | 90% | 98% | Human serum | Saxena et al. (2013) | Detection of NS1 antigen |
| Real‐time RT‐PCR | Antigen | 10 copies | 100% | Viral strains | Barros et al. (2013) | Detection and differentiation between WNV and JEV; specificity evaluated using DEN‐1–4, JEV, YFV, ZIKAV, Ntaya, TBEV, USUV, Toscana, CHIKV |
| Real‐time RT‐PCR | Antigen | 1.26 TCID50/ml for WNV‐L1, 6.3 TCID50/ml for WNV‐L2 | 100% | Tissue, feathers, oropharyngeal and cloacal swabs and blood from wild birds, samples from mice infected experimentally | Del Amo et al. (2013) | Detection and differentiation between WNV and USUV; specificity evaluated using SLEV, MVEV, JEV, BAGV, DEN‐1, TBEV, VEEV, VSV, AIV, EIV, NDV, AHS4 |
| Competitive ELISA | Antibodies | 100% | Wild birds: 79.5% compared to VNT | Sera from mammals and wild birds | Sotelo et al. (2011a) | |
| Horses: 96.5% compared to VNT | ||||||
| South african mammals: 79.5% compared to HAI | ||||||
| Giraffes: 67% compared to HAI | ||||||
| IgM capture ELISA | Antibodies | 91.7% | 99.2% | Horse sera | Long et al. (2006) | |
| Real‐time RT‐PCR | Antigen | 2–4 genome copies of WNV | 100% | Viral strains | Eiden et al. (2010) | In OIE manual. For simultaneous detection and differentiation of WNV Lineage 1 and Lineage 2. Specificity evaluated using TBEV, YFV, JEV |
| Nested RT‐PCR | Antigen | 10–8.0/100 μL | ND | Equine brain, blood, and cerebrospinal fluid; avian brain tissues | Johnson et al. (2001) | In OIE manual |
| Real‐time RT‐PCR | Antigen | 0.1 PFU | 100% | Human serum, CSF, brain tissue, mosquito pools, and avian tissues | Lanciotti et al. (2000) | In OIE manual. Specificity evaluated using DEN‐2, JEV, YFV, SLEV, Lacrosse virus, Powassan virus, MVE, WEEV, EEEV |
RT‐PCR: reverse transcriptase polymerase chain reaction; IgM: immunoglobulin M; ELISA: enzyme linked immunosorbent assay; PFU: plaque‐forming unit.