| Laboratory Method | Advantages | Disadvantages | ASSAY (Turnaround Time) |
|---|---|---|---|
| Viral Culture | Recovering of the viral strain for characterisation Open system for detecting multiple viral pathogens |
Labour-intense and time-consuming; lower sensitivity than NAAT; multiple cell lines required for the most prevalent RVs; new RVs do not grow or grow poorly in cell culture; expertise and appropriate infrastructure needed | Traditional viral culture (7-10 days) Shell-vial assay (24-48 h) |
| Antigen Detection | Rapid and easy to perform Point-of-care assay Especially useful for detection of RSV, Flu A and Flu B in paediatric patients |
Variable sensitivity depending on the commercial assay, type of patient and/or sample, viral target; lower sensitivity for detection of RV in adults | Immunofluorescence (1-2 h) Immunochromatography (15-30 min) |
| NAAT | Greater sensitivity than viral culture and antigen detection methods Method of choice for detection of new RV |
At least a part of the viral genome must be known in order to design adequate primers and probes | Conventional end-point PCR (1-4 h): commercial & “in-house”; monoplex & multiplex Real time PCR (45-90 min): commercial & “in-house”; monoplex & multiplex |
| Two-by-Two Comparison of Different NAAT Assays | |||
| Real time PCR vs conventional PCR | Reduced cross-contamination; less handling and turnaround time | Real-time instruments and fluorescent probes increase overall costs; the limited number of fluorophores with different wavelengths hampers highly multiplexing protocols | |
| Commercial vs “in house” PCR | Validated and controlled reagents for in vitro diagnosis | Only available for the most prevalent viruses; more expensive | |
| Multiplex vs multiple monoplex PCR | Cost saving; easier and faster processing of runs | More difficult to design and optimize; sensitivity and specificity is usually inversely proportional to the number of viral targets | |
| RT + PCR vs one-step RT-PCR | Versatility; any viral target can be amplified from the cDNA product | Higher risk of cross contamination | |