The seropositive rates of HBoV1, 2, and 3 in children increased with age according to results from the ELISA without competition. The rates for HBoV1, 2, and 3 reached to 77.9%, 61.1%, and 58.9%, respectively, in the age group 5-14 years. The seroprevalence for HBoV4 among children aged 0-0.5 year and 5-14 years increased from 10.3% to 31.6% (Table 1) . However, according to results of the cELISA, the seroprevalences of HBoV1, 2, 3, and 4 IgG decreased about 10-27% (Table 1, Figure 5 ). The seroprevalence among children aged 0-0.5 years and children aged 5-14 years increased from 6.9% to 60%, 6.9% to 49.5%, and 6.9% to 38.9% for HBoV1, HBoV2, and HBoV3, respectively, in the cELISA.