The 258 children tested for 16 viruses were analyzed for clinical characteristics. Median age of 46 children with acute HBoV infection diagnosed by serologic analysis and PCR of serum was 1.3 years (range 0.3-6.1 years), median age of 91 of 258 nonexposed seronegative children was 1.1 years (range 0.2-4.2 years), and median age of 110 of 258 children with HBoV immunity was 2.8 years (range 0.5-5.2 years) (p<0.0001).