Methods: Analytical comparison: Ten stocks of know adenovirus serotypes representing genogroups A-F were diluted in M4 media and tested on RP2, RP1.7 and LD PCR to determine the relative limits of detection (LOD). Clinical comparison: A total of 423 pediatric nasopharyngeal samples were tested using RP2, RP1.7, adenovirus LD PCR. In addition we performed genotyping PCRs on most adenovirus positive samples based on the availability.
Results: Analytical evaluation revealed that for the 10 serotypes (18, 32, 7, 14, 5,6, 20, 29, 4 and 40), RP2 showed at least 100 fold increase in sensitivity for six serotypes representing genogroups A, D and F. For B, C and E, the relative LODs were comparable.
In the 423 clinical samples, there was an overall agreement of 94% between RP2 and RP1.7. Among those RP2+/RP1.7- samples (n=20), 17 samples were confirmed ADV positive by LD PCR. They all had low viral burden (Ct values >30), among them 9 samples had sole detections of adenovirus types A, D and F. Five samples were RP2-/RP1.7+, two samples were confirmed by LD PCR and both were type C. Overall, there was a 22% increase in Adenovirus with RP2 compared to RP1.7.
Conclusion: The RP2 adenovirus assay has enhanced inclusivity and lower LOD for all adenovirus genogroups in comparison to RP1.7. Coupled with its faster run time and additional targets, RP2 represents a significant improvement for the syndromic detection of respiratory infections.
L. Xu, None
A. Leber, Nationwide Children's Hospital: Research Contractor , Research support .