Seroprevalence of hepatitis B and immune response to hepatitis B vaccination in Chinese college students mainly from the rural areas of western China and born before HBV vaccination integrated into expanded program of immunization.

The prevalence of hepatitis B surface antigen (HBsAg) in a population aged 15 y or older was high in China, but an immunization strategy for this population was unavailable. We investigated the seroprevalence of hepatitis B and immune response to HBV vaccine in Chinese college students (n=2040 participants), 11.1%, 80.8%, and 8.1% had confirmed, unknown and no HBV vaccination history, respectively. The seropositive rates for HBsAg, anti-HBs sole and anti-HBs plus anti-HBc were 12.6%, 25.7%, and 30.1%, respectively. The HBsAg seropositive rate was significantly lower in participants with confirmed HBV vaccination history than in those with unknown or no vaccination history (5.3%, 13.6%, and 12.6%, respectively, P=0.0019). The anti-HBs alone seropositive rate was significantly higher in participants with confirmed HBV vaccination history than in those with unknown or no vaccination history (37.6%, 25.3%, and 13.8%, respectively, P<0.0001). Participants negative for HBsAg, anti-HBs, and anti-HBc at baseline (n=600) were given three doses of recombinant HBV vaccine (GlaxoSmithKline) at month 0, 1, and 6. Robust immune response was elicited after two and three doses (seroprotective rate: 91.9% and 99.0%, respectively, and geometric mean concentration [GMC]: 95.8 and 742.6 IU/L, respectively). Fourteen months after the third dose, the anti-HBs seroprotective rate of the group remained more than 97%. The seroprotective rates and GMCs did not differ significantly by vaccination history. This study suggested that three doses of 20 µg HBV vaccine were needed for college students negative for HBsAg, anti-HBs, and anti-HBc to ensure high seroprotective rates and concentrations.

[Infection status of freshwater fishes with metacercariae of Clonorchis sinensis in Liujiang River of Guangxi].

From March 2008 to March 2009, fishes were caught from the rivers in Sanjiang, Rongan, Rongshui, Liucheng, Liuzhou and Xiangzhou counties, and their metacercarial infections were examined by the muscle compression and digestion techniques. A total of 16,204 freshwater fishes of 35 species were collected. C. sinensis metacercariae were found in 32 species of fishes with an overall infection rate of 10.5% and a mean infection intensity of 4.6 metacercariae per gram. The highest prevalence (21.5%) and intensity of infection (9.9 per gram) were found in Pseudorasbora parva, followed by Zacco platypus (17.8% and 8.9 per gram, respectively). There were significant differences in infection rate among different localities. The infection rate in Xiangzhou County (12.3%) was higher than that in Sanjiang County (9.1%) and Liuzhou City (9.7%). The infection rate was higher in summer and autumn, but lower in spring and winter. Compared with low water layer, the infection rate was higher in the upper and medium water layers. The infection rates of omnivorous and herbivorous fishes were higher than that of carnivorous fishes.