[Ten years outcome observation of infants with hepatitis C virus mother to infant transmission].

OBJECTIVE: To study the outcome of hepatitis C virus (HCV) vertical transmitted infants. METHODS: Thirteen HCV vertical infected infants were followed up for 10 years. HCV antibody and HCV RNA in the blood samples from them were tested using second generation HCV antibody EIA kits and RT-PCR, respectively. RESULTS: Among the 13 infants, one developed clinical hepatitis C, and serum HCV antibody and HCV RNA could be detected for 7 and 8 years, respectively. Three were subclinical hepatitis C, serum HCV antibody continued to be positive for 12 months (2 infants) and 24 months (1 infant), respectively, and serum HCV RNA turned to be negative at the 24th month (2 infants) and the 60th month (1 infant), respectively. Nine were HCV insidious infection, whose serum HCV antibody and HCV RNA turned to be negative in 12 months. During the eight to ten years, there was no infants with anti-HCV or HCV RNA positive again. CONCLUSIONS: It is rarely happened that vertical transmitted HCV induce chronic HCV carrying state and chronic viral hepatitis, and most of the infected infants have good outcome.

[Efficacy of recombinant hepatitis B vaccine and low-dose hepatitis B immune globulin in preventing mother-infant transmission of hepatitis B virus infection].

OBJECTIVE: To determine the efficacy of recombinant hepatitis B (rHB) vaccine and low-dose hepatitis B immune globulin (HBIG) in the prevention of mother-infant transmission of hepatitis B virus (HBV) infection. METHODS: rHB vaccine was administered to two groups of healthy neonates born to mothers with both hepatitis B surface antigen and e antigen positive in Guangxi, Hunan and Hebei province. Two hundred eighty-nine subjects were included in active immunization group, receiving triple doses of rHB vaccine given i.m. at 0, 1 and 6 month intervals; while 186 subjects receiving 50 IU HBIG at birth with triple doses of rHB vaccine in the low-dose HBIG group. RESULTS: Efficacy of active immunization alone was 87.8% (95% CI: 83.6 - 91.9). Efficacy of rHB vaccine and HBIG was 91.2% (95% CI: 86.7 - 95.6). No significant differences in efficacy by type of rHB vaccine (P = 0.707 2), immunoprophylaxis programs (P = 0.295 5) and regions of living (P = 0.998 7) were noticed. Seroprotection rates (anti-HBs >or= 10 mIU/ml) were detected in 91.1% and 93.5% in rHB vaccine alone recipients and rHB vaccine plus HBIG recipients, with geometric mean titer (GMT) of 153 mIU/ml and 164 mIU/ml at 1 year of age, respectively. Anti-rHBs decreased significantly with years after vaccination (chi(2) = 60.47, P = 0.000 1). Seroprotection rates of anti-rHBs antibodies decreased to 65.0% and 66.6% at 4 years of age in rHB vaccine alone recipients and rHB vaccine plus HBIG recipients, with GMT of 55 mIU/ml and 56 mIU/ml, respectively. CONCLUSION: These results suggested that the effectiveness of rHB vaccine plus low-dose HBIG was much better than only active plasma-derived vaccine; however, methods used for anti-rHBs assay need to be evaluated and verified.

A 12-year cohort study on the efficacy of plasma-derived hepatitis B vaccine in rural newborns.

AIM:To understand the anti HBs persistence and the long-term preventive efficacy in rural newborns after vaccination with plasma-derived hepatitis B vaccine.METHODS:In the time of expanded program on immunization (EPI), the newborns were vaccinated with 10&mgr;gcenter dot3 doses of hepatitis B vaccine and 762 newborns who were HBsAg negative after primary immunization were selected for cohort observation from 1986 to 1998. Their serum samples were detected qualitatively and quantitatively for hepatitis B infecting markers, including HBsAg, anti-HBs and anti-HBc by SPRIA Kits. The annual HBsAg positive conversion rate was counted by life-table method.RESULTS:(1)The anti-HBs positive rate was 94.44% for the babies born to HBsAg negative mothers and 84.21% for those born to HBsAg positive mothers in the 1st year after immunization, and dropped to 51.31% and 52.50% in the 12th year respectively.GMT value was dropped from 31.62 to 3.13 and 23.99 to 3.65 in the 2nd to the 12th year respectively. There was a marked drop in GMT at the 3rd to the 5th year, and in anti HBs positive rate at the 9th to the 10th year. (2) In the period of 12 years observation, the person-year HBsAg positive conversion rates were 0.12% (5/4150.0) in newborns born to HBsAg negative mothers and 0.20% (1/508.0) in those born to HBsAg positive mothers, and none of the HBsAg positive converted children became HBsAg chronic carriers. Compared with the baseline before immunization, the protective rates were 97.19% and 95.32% respectively.CONCLUSION:The protective efficacy of plasma-derived hepatitis B vaccine persisted at least 12 years, and a booster dose seems not necessary within at least 12 years after the primary three-doses immunization to newborns born to HBsAg negative mothers.

H2 strain attenuated live hepatitis A vaccines:protective efficacy in a hepatitis A outbreak.

AIM:To investigate the protective efficacy of H2 strain attenuated live hepatitis A vaccines (H2-strain vaccines) in hepatitis A (HA) outbreaks.METHODS:With the permission of their parents, 5551 pre-school and grade 1-3 primary school children were inoculated with 1 dose (10(6.5) TCID(50)) of H2 strain vaccines in a nonrandomized, controlled trial conducted in Fucheng County, Hebei Province in May 1997.Another 6485 children in the same grades and compatible in gender and age were enrolled as controls. Epidemiological and serological survey was conducted to evaluate the protective efficacy of the vaccines. ELISA was used to detect serum IgM anti-HAV.RESULTS:HA outbreak started in early May 1998, peaked in the middle of the same month, and lasted about 80 days. Overall 302 HA cases were found, 192(63.58%) were 5-9 years old. One vaccinee and 25 control cases were found to have hepatitis A, which account for 0.28% (1/356) and 5.92% (25/422) of all vaccinees and controls in the 14 villages, respectively. The protective efficacy of vaccines was 95.27% (95% CI: 85.83%-104.72%). In subjects tested for anti-HAV IgM from 13 villages, 1(0.40%) overt and 11(4.06%) asymptomatic HAV cases were found in 271 vaccinees but 21(6.69%) of overt and asymptomatic ones were found in 314 controls.CONCLUSION:H2 strain vaccines were excellent in preventing overt hepatitis A,but not so effective in preventing asymptomatic hepatitis A virus infection.A booster dose might be needed to get permanent reliable immunity.