Objective To determine the factors responsible for failed postnatal immunoprophylaxis for hepatitis B virus(HBV) in Qidong, China. Methods Eleven children who developed into chronic HBV infection after receiving HBIG and HBV recombinant vaccines were recruited into the study. Eleven paired mothers with chronic hepatitis and other 6 mothers whose children successfully generated anti-HBs after im-munoprophylaxis were included as the control in the study. Full-length HBV DNA was amplified through ser-um sample by PCR method and underwent cloning and sequencing. HBV DNA level was quantified by real-time PCR. Results The mean levels of HBV DNA in mothers who had HBV DNA positive children and healthy children were ( 1.2 ×107± 3.1 × 106 ) copies/ml and ( 1.6× 107±8.8×106 ) copies/ml, respec-tively. There was no significant difference between the groups (P >0.05). Meanwhile, viral load in chil-dren was unrelated to that in their mothers (r2 =0.2429). In 11 HBV DNA positive children, 4(36.4% ) demonstrated amino acid substitutions in HBsAg "a" determinant region with 6 different types, I.e. T125A, I126T, Q129H, M133V, D144V and G145A. All of the mothers showed the wild-type sequence in "a" epitope, indicating surface escape mutants were not acquired from the initial infection, but developed under the immune pressure. The mutation rates after immunoprophylaxis for preS1, preS2, S, X, preC/C and P genes were 0.38%, 0. 22%, 0.27%, 0.17%, 0.11%, and 0.11%, respectively, nt2999-3157 in preS1, nt529-677 in S, nt1955-2016 in C, nt923-1001 and nt2489-2602 in P genes were among the hottest muta-tional spots throughout the HBV genome. Conclusion HBV mutation may occur in all the open readingframes after passive and active immunoprophylaxis. In addition to S gene, HBV preS and P genes could alsoassociate with the escape mutants.

ObjectiveTo investigate the HBsAg seroprevalence in the young generation in Qidong of Jiangsu Province, China. MethodsA total of 15 534 students for college entrance examination from 2006 to 2014 were randomly selected from three secondary schools in Qidong as student group. Some of them had hepatitis B vaccination at birth. A total of 1208 adults who had their routine checkups in our hospital from 2007 to 2013 were selected as adult group. It was confirmed that all of them did not have hepatitis B vaccination at birth. Serum HBsAg levels of the two groups were measured using enzyme-linked immunosorbent assay and the seroprevalence was analyzed. Comparison of data between the two groups was made by chi-square test. Results In the 9 years from 2007 to 2013, the seroprevalence rates of HBsAg in the student group were 4.2%(75/1794), 4.3%(77/1797), 4.4%(82/1858), 4.3%(82/1903), 3.4%(56/1627), 2.6%(46/1768), 1.6%(29/1778), 1.6%(27/1642), and 1.8%(24/1367), respectively. The mean HBsAg seroprevalence of the student group was 32%(498/15534), significantly lower compared with 7.1% (86/1208) of the adult group (χ2= 59.986, P＜0.001). In both of the student group and the adult group, the males had a significantly higher HBsAg seroprevalence than the females (χ2=10.521, P=0001; χ2=8.452, P=0.004) and the values were 3.7%(266/7236) vs 2.8%(229/8298) and 8.8%(66/750) vs 4.4%(20/458), respectively. Among male subjects, the HBsAg seroprevalence of the adult group was 2.4 times that of the student group; among female subjects, the HBsAg seroprevalence of the adult group was 1.6 times that of the student group. ConclusionIn the recent 9 years from 2006 to 2014, the HBsAg seroprevalence in students for college entrance examination declined continuously. The goal set by the World Health Organization Western Pacific Region in 2010 had been achieved ahead of the schedule that the HBsAg seroprevalence should be controlled below 2% in children aged less than 5.

OBJECTIVETo evaluate the long-term protection efficacy of neonatal hepatitis B vaccination on chronic hepatitis B (CHB) and liver fibrosis and cirrhosis in adults.

METHODSFrom January to October, 2013, a cross-sectional study was conducted among the participants from Qidong Hepatitis B Intervention Study (QHBIS), who were selected through stratified random sampling. The detections of serum alanine aminotransferase (ALT), HBsAg, anti-HBs, anti-HBc, HBeAg, and anti-HBe were conducted and ultrasonography on liver, gallbladder and spleen was performed for them. The positive rates of each serologic markers, the prevalence of active CHB and liver fibrosis and cirrhosis were calculated, the gender specific differences between vaccination group and control group were compared with Chi-square test.

RESULTSA total of 4 421 participants aged (25.59±1.84) years in vaccination group and 3 880 participants aged (26.61±2.24) years in control group were surveyed. The positive rates of HBsAg, anti-HBs, anti-HBc, HBeAg and anti-HBe were 2.38%, 37.73%, 3.78%, 0.57% and 2.15% in vaccination group, and 9.02%, 29.41%, 16.83%, 2.73% and 8.87% in control group, respectively, the differences between two groups were statistically significant (all P<0.05). The prevalence of active CHB and liver fibrosis and cirrhosis were 0.45% and 0.16% in vaccination group, 1.29% and 0.39% in control group, the differences between two groups were statistically significant (P<0.05). The active CHB prevalence was lower in females than in males in both vaccination group and control group (P<0.05). The liver fibrosis and cirrhosis prevalence was lower in females than in males in control group (P<0.05); whereas, no statistical significant difference in liver fibrosis & cirrhosis prevalence between males and females was found in vaccination group (P>0.05).

CONCLUSIONSProtection conferred by neonatal hepatitis B vaccination could last to marrying age. The gender specific difference in protection efficacy needs further study.

Adult ; China ; Cross-Sectional Studies ; Female ; Hepatitis B Antibodies ; blood ; Hepatitis B Surface Antigens ; blood ; Hepatitis B Vaccines ; therapeutic use ; Hepatitis B virus ; Hepatitis B, Chronic ; prevention & control ; Humans ; Liver Cirrhosis ; Male ; Prevalence ; Vaccination ; statistics & numerical data