Development and evaluation of real-time PCR assays for the detection of the newly identified KI and WU polyomaviruses

BACKGROUND: Recently, novel human polyomaviruses, KI (KIV) and WU (WUV) were described. Their role in human disease has not yet been determined. OBJECTIVES: The aim of this study was to develop sensitive and specific assays for the detection of KIV and WUV. STUDY: Two KIV (KI-A and KI-B) and three WUV (WU-A, WU-B and WU-C) real-time polymerase chain reaction (rtPCR) assays were developed and evaluated. Clinical sensitivities and specificities were determined by testing 200 respiratory specimens and the results compared to those for previously described conventional PCR assays. Limits of detection were determined, and the analytical specificities of the assays were investigated. RESULTS: No cross-reactivity was observed between the rtPCR methods and unrelated organisms. All five rtPCR assays could reliably detect 10 copies of genomic DNA equivalents per reaction, which was more sensitive than conventional methods. Compared to the conventional PCR assays, the sensitivity of the KI-A, KI-B, WU-A, WU-B and WU-C assays was 100%, 86.7% 95.5%, 100% and 100%, respectively. Specificity was 94.6%, 97.3%, 96.6%, 97.7% and 97.2%, respectively. CONCLUSIONS: The KI-A, WU-B and WU-C assays provide the most sensitive detection of KIV and WUV in clinical specimens and may be used for further research into these viruses.