Prevalence and patterns of polyomavirus urinary excretion in immunocompetent adults and children.

BK and JC polyomavirus infections are acquired commonly during childhood, mainly asymptomatically. These viruses are thought to remain latent in renal tissue after the primary infection and to reactivate under certain conditions. This reactivation leads to urinary excretion of virus particles, which can be detected by a range of methods. However, while this reactivation has been studied in depth in immunocompromised patients, little information is available about healthy individuals. The present study used PCR-based methods to examine urine samples from healthy individuals (51 adults and 15 children), and found that 62.7% of adults and 13.2% of children excreted polyomaviruses in the urine, mostly JC virus (41.2%). JC virus excretion was continuous, while BK virus excretion was mostly occasional.