[Epidemiological distribution of genotypes and sub-genotypes of hepatitis B virus in 15 ethnic groups in China].

Objective: To understand the distribution of genotypes and sub-genotypes of HBV in different ethnic groups in China. Methods: The HBsAg positive samples were selected by stratified multi-stage cluster sampling from the sample base of national HBV sero-epidemiological survey in 2020 for the amplification of S gene of HBV by nested PCR. A phylogeny tree was constructed to determine the genotypes and sub-genotypes of HBV. The distribution of genotypes and sub-genotypes of HBV were analyzed comprehensively by using laboratory data and demographic data. Results: A total of 1 539 positive samples from 15 ethnic groups were successfully amplified and analyzed, and 5 genotypes (B, C, D, I and C/D) were detected. The proportion of genotype B was higher in ethnic group of Han (74.52%, 623/836), Zhuang (49.28%, 34/69), Yi (53.19%, 25/47), Miao (94.12%, 32/34), Buyi (81.48%, 22/27). The proportions of genotype C were higher in ethnic groups of Yao (70.91%, 39/55). Genotype D was the predominant genotype in Uygur (83.78%, 31/37). Genotype C/D were detected in Tibetan (92.35%,326/353). In this study, 11 cases of genotype I were detected, 8 of which were distributed in Zhuang nationality. Except for Tibetan, sub-genotype B2 accounted for more than 80.00% in genotype B in all ethnic groups. The proportions of sub-genotype C2 were higher in 8 ethnic groups, i.e. Han, Tibetan, Yi, Uygur, Mongolian, Manchu, Hui and Miao. The proportions of sub-genotype C5 were higher in ethnic groups of Zhuang (55.56%, 15/27) and Yao (84.62%, 33/39). For genotype D, sub-genotype D3 was detected in Yi ethnic group and sub-genotype D1 was detected in both Uygur and Kazak. The proportions of sub-genotype C/D1 and C/D2 in Tibetan were 43.06% (152/353) and 49.29% (174/353). For all the 11 cases of genotype I infection, only sub-genotype I1 was detected. Conclusions: Five genotypes and 15 sub-genotypes of HBV were found in 15 ethnic groups. There were significant differences in the distribution of genotypes and sub-genotypes of HBV among different ethnic groups.

[Epidemiological distribution of hepatitis B virus genotypes in acute hepatitis B cases in China,2015-2017].

Objective: To analyze the genotype distribution of acute hepatitis B virus in China. Methods: A total of six hundred and twenty acute Hepatitis B cases reported to China Information System for Diseases Control and Prevention from 2015 to 2017 were selected. First, the full-length HBV genome was obtained by nested PCR amplification. In addition, the HBV genotype was determined by constructing a phylogeny tree. Finally, using primarydata, HBV genotype distribution was analyzed. Results: A total of 519 (83.71%, 519/620) sequences were obtained genotype of 620 acute hepatitis B cases, including A (0.19%, 1/519), B (27.17%, 141/519), C (62.04%, 322/519), D (9.06%, 47/519), I (0.77%, 4/519) and C/D (0.77%, 4/519); B2(95.03%, 134/141) and C2 (72.67%, 234/322) were the two major subgenotypes. Genotypes were distributed differently in seven regions of China. The proportion of genotype C appeared higher in Northeast China (94.55%, 52/55), North China (93.85%, 61/65), East China (78.87%, 56/71), and South China (58.14%, 50/86). The proportion of genotype B was higher in Central China (58.07%, 36/62) and Southwest China (52.94%, 45/85), the proportion of genotype D was the highest in Northwest China (48.42%, 46/95). A total of 515 cases were classified as serotypes, including 'adr' (57.48%, 296/515), 'adw' (30.87%, 159/515), 'ayr' (0.19%, 1/515), and 'ayw' (11.46%, 59/515). Genotype B was dominated by 'adw' serotype (92.14%, 129/140), genotype C was dominated by 'adr' serotype (91.88%, 294/320),all genotype D were 'ayw' serotype. The genotype of acute hepatitis B was correlated with serotype, 'adw' was dominant in genotype B, 'adr' was dominant in genotype C and 'ayw' was dominant in genotype D.In different gender and age group, there was no statistical significance ingenotype distribution (P>0.05). Conclusions: The genotype of acute hepatitis B in China from 2015 to 2017 was mainly B, C, and D; genotype C was dominant in the Northeast China,North China, East China and South China; B and C were common in Central and Southwest China, and genotype B was dominant. Genotype D was primarily distributed in Northwest China. The genotype of acute hepatitis B was correlated with serotype, 'adw' was dominant in genotype B, 'adr' was dominant in genotype C and 'ayw' was dominant in genotype D. There was no difference in the distribution of acute hepatitis B genotypes among different genders and age groups.

[Sero-epidemiological characteristics of hepatitis E in population aged 1-29 years in China, 2014].

Objective: To analyze the epidemiological characteristics of hepatitis E Virus antibody (anti-HEV) in people aged 1-29 years in China in 2014. Methods: Based on database of the national serologic survey of hepatitis B in people aged 1-29 years in China, in 2014, the sample size was estimated. The serum samples of the people surveyed were randomly selected to detect anti-HEV IgG by using enzyme- linked immunosorbent assay (ELISA). Statistical software SAS 9.1.3 was used to calculate the positive rate of anti-HEV and 95% confidence interval (CI) in different age, gender groups, urban and rural areas and geographic areas by using the Taylor series linear method with sampling weight. The difference was determined by comparing 95%CI. Results: A total of 14 106 serum samples were detected from people aged 1-29 years, including 6 996 males (49.60%), 7 013 urban residents (49.72%). The positive rate of anti-HEV was 8.12%(95%CI: 7.19-9.15) in people aged 1-29 years. There was no statistical difference between the men and women, between urban area and rural area. The positive rates of anti-HEV in western area(11.36%, 95%CI: 9.45-13.62) was higher than those in eastern and central areas. The positive rates of anti-HEV were 2.46%, 2.24%, 4.50%, 7.58%, 11.89% and 17.27% in people aged 1-, 5-, 10-, 15-, 20- and 25-29 years, respectively. As the age increased, the positive rate of anti-HEV gradually increased. In different ethnic groups, the positive rate of anti-HEV was higher in Tibetan (18.32%, 95%CI: 12.02-26.90), Zhuang (9.54%, 95%CI: 4.33-19.73) ethnic groups. Conclusion: The positive rate of anti-HEV declined slightly in China in 2014. It is still necessary to pay close attention to the HEV infection, morbidity of hepatitis E and risk factors in people aged 1-29 years.

[Comparative analyze on hepatitis B seroepidemiological surveys among population aged 1-29 years in different epidemic regions of China in 1992 and 2014].

Objective: To evaluate the effect of hepatitis B prevention and control by comparative analysis on the results of HBsAg, anti-HBs and anti-HBc prevalence from national hepatitis B seroepidemiological surveys in 1992 and 2014 in different epidemic regions of China. Methods: Data was from the national seroepidemiological surveys of hepatitis B conducted in 1992 and 2014. The survey in 1992 was conducted in 145 disease surveillance points of 30 provinces (excluding Hong Kong, Macao Special Administrative Region and Taiwan province) in China. The survey in 2016 was conducted in 160 disease surveillance points of 31 provinces (excluding Hong Kong, Macao Special Administrative Region and Taiwan province) in China. In the two surveys, face-to-face interviews with the subject by door to door or on the investigation site were conducted by trained staff using standard questionnaires to obtain basic information including birth date, gender, ethnicity, resident place and so on. And then 5 ml venous blood was collected to test the sero-markers of HBsAg, anti-HBs and anti-HBc. We analyzed unweighted point prevalence and 95% CI of HBsAg, anti-HBs and anti-HBc in 1992 which had no design weighting, and analyzed weighted point prevalence and 95%CI of HBsAg, anti-HBs and anti-HBc in 2014 which had design weighting. Results: 34 291 and 31 713 people aged 1-29 years were involved in 1992 and 2014 national serosurveys of China, respectively. For the people aged 1-29 years, HBsAg prevalence was 2.64% (95%CI: 2.28%-3.06%) in 2014 and decreased by 73.92% as compared with the rate 10.13% (95% CI: 9.81%-10.45%) in 1992. Anti-HBc prevalence was 13.01% (95%CI: 12.09%-14.00%) in 2014 and decreased by 71.61% as compared with the rate 45.84% (95% CI: 45.31%-46.37%) in 1992. Anti-HBs prevalence was 57.79% (95%CI: 56.33%-59.25%) in 2014 and ascended by 127.41% as compared with the rate 25.41% (95% CI: 24.95%-25.87%) in 1992. In high, medium and low epidemic region, for the people who born during 1992-2001 when hepatitis B vaccine was introduced in routine immunization management, HBsAg prevalence was 4.74% (95%CI: 3.79%-5.69%), 1.59% (95%CI: 1.09%-2.10%) and 2.53% (95%CI: 1.66%-3.39%), respectively, and anti-HBs prevalence was 64.25% (95% CI: 62.11%-66.39%), 56.34% (95% CI: 54.50%-58.57%), 54.49% (95%CI: 51.75%-57.23%), respectively, and anti-HBc prevalence was 15.16% (95%CI: 13.56%-16.76%), 11.07% (95%CI: 9.80%-12.33%), 7.61% (95%CI: 6.15%-9.07%), respectively. In high, medium and low epidemic region, for the people who born during 2002-2013 the duration which hepatitis B vaccine was integrated in expanded immunization program born during when HBsAg prevalence was 0.88% (95%CI: 0.66%-1.11%), 0.37% (95%CI: 0.24%-0.49%)and 0.71% (95%CI: 0.48%-0.94%), respectively, and anti-HBs prevalence was 60.74% (95%CI: 59.57%-61.90%), 59.46% (95%CI: 58.44%-60.49%), 52.56% (95% CI: 51.20%-53.92%), respectively, and anti-HBc prevalence was 3.30% (95% CI: 2.87%-3.72%), 1.91% (95%CI: 1.63%-2.20%), 2.25% (95%CI: 1.85%-2.66%), respectively. Conclusion: China had made great achievement in hepatitis B prevention and control. HBsAg prevalence among people aged 1-29 years old in 2014 decreased dramatically as compared with that in 1992. Since hepatitis B vaccine was integrated into expanded immunization program, China reduced HBsAg prevalence to less than 1% among people aged 1-12 years in 2014 in different epidemic region.

Long-term effectiveness of plasma-derived hepatitis B vaccine 22-28 years after immunization in a hepatitis B virus endemic rural area: is an adult booster dose needed?

Longan County is considered a highly endemic area for hepatitis B virus (HBV). The plasma-derived vaccine has been used in newborns in this area since 1987. A cross-sectional survey was conducted to evaluate the long-term effectiveness of this vaccine. In total, 1634 participants born during 1987-1993 and who had received a series of plasma-derived HB vaccinations at ages 0, 1, and 6 months were enrolled. Serological HBV markers were detected and compared with previous survey data. Overall the prevalence of hepatitis B surface antigen (HBsAg) in all participants was 3·79%; 3·47% of subjects who had received the first dose within 24 h were HBsAg positive, and 8·41% of subjects who had received a delayed first dose were also HBsAg positive. There were 1527 subjects identified who had received the first dose within 24 h and whose HBsAg and anti-HBc prevalence increased yearly after immunization, while the anti-HBs-positive rate and vaccine effectiveness declined. The geometric mean concentration of antibody in the anti-HB-positive participants was 55·13 mIU/ml and this declined after immunization. Fewer than 2·0% of participants had anti-HB levels ⩾1000 mIU/ml. The data show that the protective efficacy of the plasma-derived vaccinations declined and administration of HB vaccine within 24 h of birth was very important. To reduce the risk of HBV infection in this highly endemic area, a booster dose might be necessary if anti-HBs levels fall below 10 mIU/ml after age 18 years. Furthermore, studies on the immune memory induced by plasma-derived HB vaccine are needed.

Epidemiological changes in hepatitis B prevalence in an entire population after 20 years of the universal HBV vaccination programme.

A universal hepatitis B vaccination programme has been conducted in Long An county since 1986. To investigate the epidemiological changes in hepatitis B virus (HBV) infection we conducted a serosurvey there in 2005. A total of 4686 subjects were enrolled and vaccination history and blood samples collected. HBV infective markers were determined by radioimmunoassay. The results were compared with the data of 1985. Our results show that the overall HBsAg prevalence was 7·5%, less than half of the prevalence reported in 1985. HBsAg and anti-HBc antibody prevalence in people born after 1985 decreased markedly. The gender difference in HBsAg prevalence was abolished in subjects aged <20 years. The administration of a first dose of vaccine within 24 h could reduce the HBsAg prevalence by half. In conclusion, the marked epidemiological changes in HBV prevalence found in this serosurvey indicate that the implementation of HBV vaccination was highly successful.

The sequence of hepatitis E virus isolated directly from a single source during an outbreak in China.

In this study an IgM antibody-mediated antigen-capture procedure for direct extraction of hepatitis E virus (HEV) RNA from clinical specimens was developed and used with an efficient method for generating viral cDNA that was subsequently sequenced using the dideoxy chain termination method. This is the first time the complete HEV genome has been isolated directly from a single human clinical specimen obtained during an outbreak of enterically transmitted non-A, non-B hepatitis. When the Chinese-derived sequence was compared with the original isolate of Burmese HEV from an experimentally infected cynomolgus macaque, the homology between the two sequences was 94% and 98.5% at the nucleotide and amino acid levels, respectively. The methods we developed for generating and sequencing genomic HEV cDNA dramatically improved the efficiency of cloning the viral genome and should be helpful for continued analysis of this virus as well as other RNA viruses that have proven to be difficult to clone and sequence directly.