Overall, the serologic prevalence of confirmed HBV infections from first-time and repeat donations is shown in Tables 5 and 6. In all, 578 samples were HBsAg positive, confirmed by neutralization assay. The overall prevalence was 0.15%. The seroprevalence of HBsAg was estimated to be 0.13%, 0.078%, 0.16%, 0.07%, 0.20%, and 0.25% at the Hefei, Dalian, Changzhi, Kaifeng, Mianyang and Fujian Blood Centers, respectively. The prevalence of HBsAg varied significantly among the six blood centers, and the prevalence in Fujian was much higher (0.25%) than all of the other blood centers. By contrast, the prevalence in Kaifeng was the lowest (0.07%) among all of the blood centers. Of all 578 reactive samples, 520 (98.5%, 520/528) were from first-time donors.Table 5HBsAg Prevalence by Blood Center / Bank Among all Donors (First-Time and Repeat)Blood CenterDonations(Total)First-TimeRepeatPrevalence(%)(Among all Donors)DonationsNumber of HBsAgConfirmed PositivePrevalence(%) (95% Confidence Intervals)DonationsNumber of HBsAgConfirmed PositivePrevalence(%) (95% Confidence Intervals)Hefei97,66860,8121150.19 (0.15-2.23)36,856100.027 (0.01-0.04)0.13 (0.11-0.15)Dalian77,39538,503520.14 (0.09-0.17)38,89280.02 (0.01-0.04)0.08 (0.06-0.09)Changzhi32,81710,643400.38 (0.26-0.49)22,174120.05 (0.02-0.08)0.16 (0.12-0.20)Kaifeng59,93840,227360.09 (0.06-0.12)19,71140.02 (0.004-0.04)0.07 (0.05-0.09)Mianyang45,49418,889770.41 (0.32-0.50)26,605120.05 (0.02-0.07)0.20 (0.16-0.24)Fujian83,55443,3842000.46 (0.40-0.52)40,170120.03 (0.013-0.05)0.25 (0.22-0.29)Total396,866212,4585200.24 (0.22-0.27)184,408580.03 (0.02-0.04)0.15 (0.13-0.16) Table 6HBV Prevalence for Blood Donors Above and Below 35 Years OldBlood CenterDonationsBelow 35Over 35 P-valueTotal PrevalenceDonationsNumber of HBsAg confirmed positivePrevalenceDonationsNumber of HBsAg Confirmed PositivePrevalenceHefei97,66869,540380.06%28,128870.31%<0.0010.13%Dalian77,39554,018160.03%23,377440.19%<0.0010.08%Changzhi32,81712,671110.09%20,146410.20%0.010.17%Kaifeng59,93827,428120.04%32,510280.09%0.0450.07%Mianyang45,49419,463210.11%26,031680.26%<0.0010.20%Fujian83,55450,383550.11%33,1711570.47%<0.0010.25%Total396,866233,5031530.07%163,3636250.38%<0.0010.20%