Complete sets of HBoV qPCR results for NPAs and serum samples were available for 258 children ( dren who showed viremia in the first sample (62%) or both samples (87%) had a high (>10 4 copies/mL) HBoV-DNA load in NPAs; most children who showed viremia only in the second sample (58%) had DNA-negative NPAs. These findings suggest a very recent infection. HBoV DNA loads in serum samples ranged from 112 copies/mL to 600,000 copies/mL and did not correlate with NPA DNA loads. Forty-nine (19%) of 258 children had NPAs that were PCR positive, but only 34 (13%) had both NPAs and serum samples that were PCR positive; 194 (75%) children had negative PCR results for both sample types (Table 1) . Of long-term follow-up serum samples, only 1/93 was PCR positive; this sample was from a child who was seronegative 5 years earlier and seroconverted during follow-up. All 115 adult serum samples were HBoV PCR negative.