Identification of the novel KI polyomavirus in the respiratory tract of an Italian patient.

Recently, a new human polyomavirus, KIV, was detected in respiratory specimens of patients with acute respiratory tract infection. Whether this reflects a causal role of the virus in the respiratory tract is still debated. To investigate the presence of KIV in respiratory samples of Italian patients and to determine the degree of similarity with other known polyomaviruses, 222 respiratory specimens collected by general practitioners between 2006 and 2007 were screened. The entire VP1 gene region was amplified and sequenced. Maximum Likelihood tree was generated by PAUP* software. One out of 222 samples tested was positive for KIV. Phylogenetic analysis indicated that this isolate clustered with other KIV isolates, while the WUV isolates seem to belong to a different lineage. The phylogenetic tree also showed that all other known polyomaviruses are quite distant from this isolate. This is the first report describing the presence of KIV in the respiratory tract of a 5-year-old Italian child with acute respiratory symptoms. Further investigations are needed to establish an etiological link of KIV with acute respiratory illness.