Shedding of polyomavirus in the saliva of immunocompetent individuals

The aim of this study was to investigate and compare the frequency of BKV, JCV, WUV, and KIV in the saliva of healthy individuals. Samples were analyzed for the presence of polyomaviruses (BKV, JCV, WUV, and KIV) DNA by real-time PCR. Of the 291 samples tested, 71 (24.3%) were positive for at least one of the screened polyomaviruses. Specifically, 12.7% (37/291) were positive for WUV, 7.2% (21/291) positive for BKV, 2.4% (7/291) positive for KIV, and 0.3% (1/291) positive for JCV. BKV and WUV co-infections were detected in 1.7% (5/291) of individuals. No other co-infection combinations were found. The mean number of DNA copies was high, particularly for WUV and BKV, indicating active replication of these viruses. Polyomavirus detection was higher among individuals 15-19 years of age (46.0%; 23/50) and ≥50 years of age (33.3%; 9/27). However, the detection rate in the first group was almost 1.7× greater than the latter. WUV infections were more frequent in individuals between the ages of 15 and 19 years and the incidence decreased with age. By contrast, BKV excretion peaked and persisted during the third decade of life and KIV infections were detected more commonly in subjects ≥50 years old. These findings reinforced the previous hypotheses that saliva may be a route for BKV transmission, and that the oral cavity could be a site of virus replication. These data also demonstrated that JCV, WUV, and KIV may be transmitted in a similar fashion.