[Evolution and regional differences in the supportive environment for influenza vaccination among the elderly population in China]

Seasonal influenza leads to a significant disease burden, and older people infected with influenza are susceptible to various complications. Influenza immunization can prevent infection effectively and significantly reduce the risk of complications and severe cases. Creating a supportive environment for vaccination is crucial in advancing the influenza vaccination rate among the elderly population. In China, the present environment for supporting influenza vaccinations among the elderly is primarily comprised of policies for free vaccination and expense reimbursement, which exhibit noteworthy regional variations across cities and regions. This study systematically analyses the supportive environment and regional disparities associated with influenza vaccination among the elderly in China. It aims to comprehend the opportunities for influenza prevention and control resulting from the current background of influenza vaccination and to identify potential health inequality challenges caused by regional differences. The findings should inform the introduction of relevant national policies and programs to protect the health and well-being of the elderly population.

[Progress in epidemiological research of norovirus infection]

With characteristics of high infectivity, diverse transmission routes and high variation, norovirus is the main pathogen of sporadic cases and outbreaks of acute gastroenteritis, resulting in a serious disease burden. This paper summarizes the latest progress in epidemiological research of norovirus infection from aspects of disease burden caused by acute gastroenteritis, virus variation and predominant strains, prevention and control measures, and immunization and vaccine development.

Molecular Epidemiology of Herpangina Children in Tongzhou District, Beijing, China, During 2019-2020

Background

The changing pattern of pathogen spectrum causing herpangina in the time of coronavirus disease 2019 (COVID-19) pandemic was unknown. The purpose of this study was to investigate the changes on the molecular epidemiology of herpangina children during 2019-2020 in Tongzhou district, Beijing, China.

Method

From January 2019 to December 2020, children diagnosed with herpangina were recruited by the staff from Tongzhou Center for Disease Control and Prevention (CDC) in Beijing. Viral RNA extraction from pharyngeal swabs was used for enterovirus (EV) detection and the complete VP1 gene was sequenced. The phylogenetic analysis was performed based on all VP1 sequences for EV genotypes.

Result

A total of 1,331 herpangina children were identified during 2019-2020 with 1,121 in 2019 and 210 in 2020, respectively. The predominant epidemic peak of herpangina children was in summer and autumn of 2019, but not observed in 2020. Compared to the number of herpangina children reported in 2019, it decreased sharply in 2020. Among 129 samples tested in 2019, 61 (47.3%) children were detected with EV, while 22.5% (20/89) were positive in 2020. The positive rate for EV increased since June 2019, peaked at August 2019, and decreased continuously until February 2020. No cases were observed from February to July in 2020, and the positive rate of EV rebounded to previous level since August 2020. Four genotypes, including coxsackievirus A6 (CV-A6, 9.3%), CV-A4 (7.8%), CV-A10 (2.3%) and CV-A16 (10.1%), were identified in 2019, and only three genotypes, including CV-A6 (9.0%), CV-A10 (6.7%) and CV-A16 (1.1%), were identified in 2020. The phylogenetic analysis showed that all CV-A6 strains from Tongzhou located in Group C, and the predominant strains mainly located in C2-C4 subgroups during 2016-2018 and changed into C1 subgroup during 2018-2020. CV-A16 strains mainly located in Group B, which consisting of strains widely distributed around the world.

Conclusions

The predominant genotypes gradually shifted from CV-A16, CV-A4 and CV-A6 in 2019 to CV-A6 in 2020 under COVID-19 pandemic. Genotype-based surveillance will provide robust evidence and facilitate the development of public health measures.

[Introduction of World Health Organization Strategies and the Technical Advisory Committee actions on viral hepatitis control and status of the elimination of viral hepatitis in China]

Viral hepatitis has been causing big threat to public health globally. The number of annual deaths caused by hepatitis surpassed the deaths caused by AIDS, tuberculosis, and malaria. World Health Organization (WHO) issued the global health sector strategy on viral hepatitis 2016-2020 (GHSS) to control its epidemic. It established the Strategies and Technical Advisory Committee on HIV, viral hepatitis, and sexually transmitted infections (STAC). This paper summarizes the GHSS goals and the keynote of the 2020 STAC meeting, analyzes the challenges and opportunities faced by China in eliminating viral hepatitis, and provides the comments on the papers on this issue, which could guide further actions.

[Hesitancy of parents towards vaccines in national immunization program in three regions in China: a cross-sectional study]

Objective: To investigate the incidence and determinants of vaccine hesitancy towards national immunization program in China and understand the current status of parents' hesitancy to different vaccines used in national immunization program. Methods: A cross-sectional survey was conducted in Beijing, Sichuan and Gansu. The methods of proportional probability sampling and convenience sampling were used to select the eligible study subjects for questionnaire surveys. Results: A total of 3 592 parents were enrolled in the study, in whom 38.22% fully accepted all the vaccines, 59.35% agreed to let their children to receive all the vaccines but showed slight concern, and 2.42% had hesitancy to the vaccines. The vaccine with the most hesitancy was polio vaccine (0.89%), followed by diphtheria pertussis tetanus vaccine (0.70%) and hepatitis A vaccine (0.64%). The dominant reason for vaccine hesitancy was the risk-benefit perception of vaccination (31.03%), followed by the low awareness of the parents (21.84%) and the inconvenience caused by distance and time (21.84%). Conclusions: The incidence of vaccine hesitancy towards national immunization program was low in parents in China, but over 50% of the parents showed concern to the vaccines. It is essential to improve the service quality of national immunization program and strengthen the health education about the vaccination to reduce the incidence of vaccine hesitancy in parents.

[Development and outlook on human challenge trial of vaccine]

Human challenge trial (HCT) is a test in which human volunteers are intentionally infected with pathogens in order to evaluate the efficacy of candidate preventive or therapeutic drugs. During the COVID-19 pandemic, the HCT of vaccines has aroused people's attention due to its significant advantages over clinical trial. This paper introduces the concept, development and application of HCT, the advantages and limitations of HCT for vaccine evaluation, and the consideration of future HCT of COVID-19 vaccine in China.

[Review on immunogenicity, safety and social value of combined vaccines for children used both at home and abroad]

Combined vaccines contain two or more antigens. Research suggested that combined vaccines could prevent multi diseases and reduce the frequency of vaccination. This article focus on combined vaccines for children used both at home and abroad, such as diphtheria-pertussis-tetanus vaccine (DTaP), measles-rubella-mumps vaccine (MMR), etc. and summarizes their immunogenicity, safety and social values, including benefits to families, vaccination workers and health services, to provide evidence for promoting the research, development and use of combined vaccines in China. We found that combined vaccines can not only ensure the immunogenicity and safety, but also give convenient and lower cost vaccination to families, and using combined vaccines can improve the work efficiency of vaccination workers, reduce the impact of the epidemic on immunization services and improve vaccination coverage and timeliness. At present, the promotion of combined vaccines in China is restricted by many technical bottlenecks, high prices, and low awareness among people. It is recommended that research on the safety, effectiveness and health economics of combined vaccines should be strengthened, and the value of combined vaccines should be scientifically evaluated; the public's awareness and trust in combined vaccines should be enhanced, as well as the development and application of multi-linked multivalent vaccines should be promoted. The government should improve regulations to assist the development and application of combined vaccines.

First line nucleos(t)ide analog monotherapy is more cost-effective than combination strategies in hepatitis B e antigen-positive chronic hepatitis B patients in China

BACKGROUND

Nucleos(t)ide analog (NA) in combination with peginterferon (PegIFN) therapy in patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) shows better effectiveness than NA monotherapy in hepatitis B surface antigen loss, termed "functional cure," based on previous published studies. However, it is not known which strategy is more cost-effective on functional cure. The aim of this study was to analyze the cost-effectiveness of first-line monotherapies and combination strategies in HBeAg-positive CHB patients in China from a social perspective.

METHODS

A Markov model was developed with functional cure and other five states including CHB, compensated cirrhosis, decompensated cirrhosis, hepatocellular carcinoma, and death to assess the cost-effectiveness of seven representative treatment strategies. Entecavir (ETV) monotherapy and tenofovir disoproxil fumarate (TDF) monotherapy served as comparators, respectively.

RESULTS

In the two base-case analysis, compared with ETV, ETV generated the highest costs with $44,210 and the highest quality-adjusted life-years (QALYs) with 16.78 years. Compared with TDF, treating CHB patients with ETV and NA - PegIFN strategies increased costs by $7639 and $6129, respectively, gaining incremental QALYs by 2.20 years and 1.66 years, respectively. The incremental cost-effectiveness ratios were $3472/QALY and $3692/QALY, respectively, which were less than one-time gross domestic product per capita. One-way sensitivity analysis and probabilistic sensitivity analyses showed the robustness of the results.

CONCLUSION

Among seven treatment strategies, first-line NA monotherapy may be more cost-effective than combination strategies in HBeAg-positive CHB patients in China.

[Comparison of antibody persistence after primary immunization with 5 μg and 10 μg recombinant hepatitis B vaccine among newborns with normal and high response: a five-year following-up]

Objective: To compare the antibody persistence 5 years after primary immunization with 5 μg and 10 μg recombinant hepatitis B vaccine (HepB) among newborns with normal and high response. Methods: Newborns who completed three doses of 5 μg HepB made by recombinant dexyribonucleic acid technique in Saccharomyces (HepB-SC) or 10 μg HepB made by recombinant dexyribonucleic acid technique in Hansenula polymorpha (HepB-HP) were recruited. Standardized questionnaire was used and blood samples were collected 1-6 months (T(0)) and five years (T(1)) after the third dose respectively. The titer of anti-HBs was detected by chemiluminescence microparticle imunoassay (CMIA). Those who achieved normal or high antibody response (anti-HBs titer ≥100 mIU/ml) were included in the study and the positive rate (≥10 mIU/ml) and titer of anti-HBs at T(1) were compared between 5 μg HepB group and 10 μg HepB group. Multivariable analysis was conducted to identify the independent factors associated with the antibody persistence. Results: The positive rate of anti-HBs at T(1) was 49.92% (943/1 883) and 75.92% (1 135/1 495) respectively in 5 μg HepB group and 10μg HepB group, the difference was significant (χ(2)=237.75, P<0.001). The anti-HBs geometric mean concentrations at T(1) were 10.23 mIU/ml (95%CI: 9.38-11.16) and 28.91 mIU/ml (95%CI: 26.65-31.35) in the two groups respectively, the difference was also significant (F=280.36, P<0.001). Among those whose anti-HBs titer was<10 mIU/ml at T(1), the distributions of anti-HBs titer were significantly different between 5 μg HepB group and 10 μg HepB group (χ(2)=39.75, P<0.001). The multivariable analysis showed that dosage of HepB was independently associated with both positive rate and titer of anti-HBs at T(1) after excluding the other factors[P<0.001, OR=1.44 (95%CI: 1.20-1.73); P<0.001, β=0.27 (95%CI: 0.14-0.40)]. Conclusion: Five year anti-HBs persistence after primary immunization with 10 μg HepB might be better than that after primary immunization with 5 μg HepB among infants who achieved normal or high anti-HBs response after primary HepB immunization.

[The risk of hepatitis B virus infection in people with diabetes mellitus: a meta-analysis]

Objective: To evaluate the relevance of diabetes mellitus and hepatitis B virus(HBV) infection in people by Meta-analysis. Methods: Databases we searched included CNKI, VIP China Science and Technology Journal Database, Wanfang Data Knowledge Service Platform, PubMed, Cochrane Library and Web of Science Core Collection database. Publication time was from January 1997 to May 2017. The Languages were limited to Chinese and English. English search terms include: diabetes, diabetes mellitus, hepatitis B and risk. Chinese search terms include: diabetes mellitus, hepatitis B and risk. We included all observational studies on diabetes and HBV infection. Firstly, the Newcastle-Ottawa Scale and the evaluation criteria of Cross-sectional study recommended by Agency for Healthcare Research and Quality were used to evaluate the quality of articles. Secondly, RevMan 5.3 software was used for heterogeneity testing. Subgroup analysis, random effects model and Mantel-Haenszel method were used to calculate the combined OR value. Finally, Stata 14.0 software was used to conduct the sensitivity analysis, and Begg rank correlation method was used to detect the publication bias. Results: A total of 12 studies were included, comprising 6 cross-sectional studies and 6 case-control studies. But the 12 articles were heterogeneous (χ(2)=42.10, P<0.001). After subgroup analysis, cross-sectional studies of diabetes and HBV infection were still heterogeneous (χ(2)=28.21, P<0.001), whose combined odds ratio (OR) was 1.36 (95%CI: 1.03-1.80). But the heterogeneity of case-control studies was not statistically significant (χ(2)=10.32, P=0.070), whose combined odds ratio (OR) was 1.55 (95%CI: 1.10-2.17). After the sensitivity analysis, the 95%CI of the combined OR of the 7 studies did not fluctuate, and the lower limit was above 1.07. No publication bias was detected in the cross-sectional study subgroup (Z=1.35, P=0.176) and the case-control study subgroup (Z=1.69, P=0.091). Conclusion: Patients with diabetes are more likely to be infected with HBV than those without diabetes. Diabetes mellitus is likely to be a risk factor for HBV infection.

[Evaluation of training course of hepatic disease in grass roots clinical hepatic physicians in some poverty-stricken counties in Shanxi and Shaanxi provinces]

Objective: To understand the awareness of hepatic disease related knowledge among hepatic physicians in poverty-stricken counties in China, assess the effectiveness of training and provide a reference for the training in the future. Methods: The training was conducted in 90 clinical hepatic physicians selected from county hospitals in poverty-stricken counties (or cities) in Shanxi and Shaanxi provinces. An examination was conducted before the training, immediately after the training and at 5(th) month after the training, respectively. One-way analysis of variance and χ(2) test were conducted to evaluate the score and the correct rate. Results: The knowledge score was (42.96±14.02) before the training, (62.86±13.28) immediately after the training and (59.03±17.92) at 5(t)h month after the training, and the differences were significant. After the training, the awareness of all aspects of related knowledge was improved, the difference was significant compared to knowledge score before training, and at 5(th) month after the training, the difference was still significant. Conclusion: After the training, the awareness of liver disease related knowledge of clinical hepatic physicians in poverty-stricken counties (cities) in Shanxi and Shaanxi provinces was improved, and the improvement could be maintained for nearly half a year.

The epidemiology of hepatitis B virus infection in women of reproductive age in highly endemic areas in China

We describe the epidemiology of hepatitis B virus (HBV) infection among women of reproductive age residing in areas of China that are highly endemic for chronic HBV, and provide evidence useful for decision-makers to guide strategies for preventing mother-to-child transmission of HBV, and assess the impact of perinatal transmission PMTCT by projecting HBsAg prevalence trends without interventions. We conducted a cross-sectional HBV serological survey of women, 15-49 years of age, residing in Fujian, Guangdong, Guangxi and Hainan provinces. Demographic and other subject-level data were collected in face-to-face interviews, after which we obtain blood specimens. Specimens were tested for HBV sero-markers by ELISA (Beijing Wantai Biological Pharmacy), and HBV DNA was tested with PCR (Hunan Sansure Biotech). Weighted HBsAg and HBV (either HBsAg+ or anti-HBc+ indicating either present or past infection) prevalences were 11.82% and 57.16%, respectively. Among the HBsAg-positive women, 27% were also HBeAg positive. The proportion of individuals with HBV DNA loads >10⁵ IU/mL declined with increasing age. Among HBsAg-negative women, 0.9% had occult HBV infection. The prevalence of chronic HBV infection among reproductive women in these highly endemic provinces is high, posing a threat to maternal health and risk of mother-to-child transmission. Prevention of mother-to-child transmission remains critically important.

[Consistency analysis on acute hepatitis B inpatients reported by hepatitis B surveillance pilot spots in six provinces of China]

Objective: To understand the characteristics of acute hepatitis B inpatients reported by the hepatitis B surveillance pilot points and to estimate the consistency between the diagnosed and reported types of hepatitis B by the clinicians involved. Methods: Data related to acute hepatitis B was from the NNDRS and the characteristics of acute hepatitis B were classified by querying Hospital Information System. We recorded the results based on clinical diagnosis and analyzed the consistency between the reported and diagnosed types that the clinicians made, on hepatitis B. Results: A total of 179 patients were included in this study with all of them as acute hepatitis B reported through NNDRS in 2015-2016. In terms of the durations of disease, among the 179 cases who were HBsAg positive, 32.40% (58/179) of them exceeding 6 months, 2.79% (5/179) within 6 months and 64.80% (116/179) tested the first time or never. Among the 179 cases who claimed having the history of hepatitis, 33.52% (60/179) of them identified as having hepatitis B, 1.12% (2/179) were hepatitis A, C or E, 41.34% (74/179) did not have the signs on hepatitis, while the rest 24.02% (43/179) did not know the situation. Only 79.89% (143/179) of the patients showed the symptoms or signs of hepatitis, but the rest 20.11% (36/179) did not. Among the 179 reported acute hepatitis patients, 67 of them were diagnosed as acute hepatitis B while 112 cases were as non-acute hepatitis B. The consistent rate of acute hepatitis B was 37.43% (67/179). Among the 112 cases that were diagnosed as non-acute hepatitis B, proportions of chronic hepatitis B and cirrhosis were 49.11%(55/112) and 16.07%(18/112) respectively. Conclusion: Consistency between the reported type of acute hepatitis B inpatients and the types diagnosed by clinicians was poor. Our results suggested that clinicians should make the accurate diagnosis at first place and then report to the Network in accordance with the clinical diagnosis classification criterfia, set by the government.

[Epidemiological characteristics of children aged 1-4 years without timely birth dose of hepatitis B vaccine vaccination in China, 2014]

Objective: To evaluate the epidemiological characteristics of the children aged 1-4 years without timely birth dose of hepatitis B vaccine (HepB(1)) vaccination. Methods: Based on the data from 160 disease surveillance points in 31 provinces of China, two-stage cluster random sampling was used to select the target population aged 1-4 years. A standard questionnaire was used to collect the information about the birth date, gender, ethnic group, place of birth, HepB immunization history of the children selected. A blood sample (3 ml) was taken from each subject for HBsAg testing. SAS software (Version 9.4) was used in our study. We analyzed the age, gender, ethnic group, area specific distributions of the children aged 1-4 years without timely HepB(1) vaccination and the influencing factors, and the relationship between the HepB(1) vaccination time and HBsAg prevalence rate. Results: A total of 12 587 children aged 1-4 years were analyzed and the non-timely HepB(1) vaccination rate was 10.12%. The place of birth, ethnic group, urban/rural area, eastern/central/western area, age were the main influencing factor of the non-timely HepB(1) vaccination. The non-timely HepB(1) vaccination rate was higher in 3-4 years old children (11.13%) than in 1-2 years old children (8.97%), in rural area (12.05%) than in urban area (8.19%), in western area (13.41%) than in central area (9.27%) and eastern area (7.72%), in minority ethnic group (18.06%) than in Han ethnic group (8.77%) and in children born outside hospital (57.66%) than in children born in hospital (9.27%). The HBsAg prevalence rate among 1-4 years children was 0.31%. The HBsAg prevalence rate of the children with timely HepB(1) vaccination (0.25%) was lower than that of the children without timely HepB(1) vaccination (0.89%). Conclusions: In China, the HBsAg prevalence rate among 1-4 years children with HepB vaccination decreased to <0.5% and the timely HepB(1) vaccination rate reached to 90%. We should strengthen the timely HepB(1) vaccination for the children in minority ethnic groups, in western area, in rural area as well as those born outside hospitals.

[Recognition of the vaccination: a key and important strategy in controlling vaccine preventable diseases]

China has achieved an outstanding accomplishment in combating infectious diseases, which has contributed to health improvement and prolongation of life expectancy, and health development globally. Among strategies for combating infectious diseases, vaccination is a key component. However, immunization rates have fallen sharply as a result of false information, inconvenient access to vaccination, and distrust which together can lead to "vaccine hesitancy", eventually resulting in the risk of endemic vaccine-preventable disease. By analyzing the importance of vaccination and its determinants, it should be recognized that vaccination is necessary to protect children's health, and considered as a key national policy with forceful strategies for the control of vaccine-preventable diseases.

Implementing the communication for development strategy to improve knowledge and coverage of measles vaccination in western Chinese immunization programs: a before-and-after evaluation

Background

Communication for Development (C4D) is a strategy promoted by the United Nations Children’s Fund to foster positive and measurable changes at the individual, family, community, social, and policy levels of society. In western China, C4D activities have previously been conducted as part of province-level immunization programs. In this study, we evaluated the association of C4D with changes in parental knowledge of immunization services, measles disease, and measles vaccine, and changes in their children’s measles vaccine coverage.

Methods

From April 2013 to April 2014, C4D activities were implemented as part of provincial immunization programs in the Inner Mongolia, Guangxi, Chongqing, Guizhou, Tibet, Shaanxi, Gansu, Ningxia, and Qinghai provinces. We used a before-and-after study design and employed face-to-face interviews to assess changes in parental knowledge and vaccination coverage.

Results

We surveyed 2 107 households at baseline and 2 070 households after 1 year of C4D activities. Following C4D, 95% of caregivers were aware of the vaccination record check requirement for entry into kindergarten and primary school; 80% of caregivers were aware that migrant children were eligible for free vaccination; more than 70% of caregivers knew that measles is a respiratory infectious disease; and 90% of caregivers knew the symptoms of measles. Caregivers’ willingness to take their children to the clinic for vaccination increased from 51.3% at baseline to 67.4% in the post-C4D survey. Coverage of one-dose measles-containing vaccine (MCV) increased from 83.8% at baseline to 90.1% after C4D. One-dose MCV coverage was greater than 95% in the Guangxi, Shaanxi, and Gansu provinces. Two-dose MCV coverage increased from 68.5 to 77.6%. House-to-house communication was the most popular C4D activity among caregivers (91.6% favoring), followed by posters and educational talks (64.8 and 49.9% favoring).

Conclusions

C4D is associated with increased caregiver knowledge about measles, increased willingness to seek immunization services for their children, and increased measles vaccination coverage. Tailored communication strategies based on insights gained from these analyses may be able to increase vaccination coverage in hard-to-reach areas. C4D should be considered for larger scale implementation in China.

Electronic supplementary material

The online version of this article (doi:10.1186/s40249-017-0261-y) contains supplementary material, which is available to authorized users.

[Anti-HBs persistence following primary vaccination with three doses of hepatitis B vaccine among normal and high-responder adults: a 3-year follow-up study]

OBJECTIVE

To assess the 3-year anti-HBs persistence after primary vaccination with three-dose of hepatitis B vaccine (HepB) among normal and high-responder adults.

METHODS

A total of 24 237 healthy adults who had no histories of hepatitis B infection and hepatitis B vaccination, resided in local areas for more than six months and were aged 18-49 years were selected from 79 villages of Zhangqiu county, Shandong province, China in 2009. Blood samples were obtained and hepatitis B surface antigen (HBsAg), antibody against hepatitis B surface antigen (anti-HBs) and antibody against hepatitis B core antigen (anti-HBc) were detected using ELISA method. A total of 11 590 persons who were negative for all of these indicators were divided into four groups by cluster sampling method. Each group was vaccinated with one of the following four types of HepB at 0-1-6 months schedule: 20 μg HepB derived in Saccharomyces cerevisiae (HepB-SC), 20 μg HepB derived in Chinese hamster ovary cell (HepB-CHO), 10 μg HepB-SC and 10 μg HepB derived in Hansenula polymorpha (HepB-HP). Blood samples were collected one month after the third dose of primary immunization and tested for anti-HBs using chemiluminescence microparticle immunoassay (CMIA). During the follow-up to normal and high-responders, the following information was collected: the demographic characteristic (including age and gender), histories of hepatitis B infection, hepatitis B vaccination, smoking, drinking and chronic diseases. Blood samples were collected one month (T1) and three years after primary vaccination (T2) and anti-HBs, anti-HBc and HBsAg (if anti-HBs<10 mU/ml) were detected by CMIA. The risk factors associated with positive rate of anti-HBs and GMC of anti-HBs were identified by multiple logistic regression analysis and multifactor linear regression model analysis, respectively.

RESULTS

A total of 4 677 normal and high-responders were identified. Among 4 677 participants, 2 014 (43.06%) were males and 2 663 (56.94%) were females. The positive rate was 100% at T1 and it decreased to 80.99% (3 788/4 677) three years after vaccination. The corresponding GMC was decreased from 1 413.48 (95%CI: 1 358.86-1 470.30) mU/ml to 60.33 (95%CI: 56.97-63.90) mU/ml. When comparing with those vaccinated 20 μg HepB-CHO, the significantly lower positive rate of anti-HBs three years after vaccination was observed in those vaccinated 20 μg HepB-SC, 10 μg HepB-SC and 10 μg HepB-HP. The OR (95%CI) was 0.65 (0.50-0.84), 0.52 (0.41-0.67) and 0.31 (0.28-0.45), respectively. The GMC of anti-HBs was also significantly lower among those vaccinated 20 μg HepB-SC, 10 μg HepB-SC and 10 μg HepB-HP. The b (95%CI) was -0.33 (-0.47- -0.20), -0.41 (-0.55- -0.28) and -0.78 (-0.92- -0.65), respectively. The GMC of anti-HBs in those aged 30-39 years old and 40-49 years old were lower than that in 18-29 years. The b (95%CI) was -0.31 (-0.47- -0.15) and -0.24 (-0.39- -0.09), respectively. When comparing with those whose anti-HBs titer was less than 999 mU/ml at T1, the significantly higher positive rate of anti-HBs three years after vaccination was observed in those whose anti-HBs titer was 1 000-1 999 mU/ml, those whose anti-HBs titer was 2 000-9 999 mU/ml and those whose anti-HBs titer was ≥10 000 mU/ml. The OR (95%CI) was 4.97 (3.80-6.49), 7.87 (16.19-10.01) and 9.67 (6.47-14.44), respectively. When comparing with those whose anti-HBs titer was ≤999 mU/ml at T1, the GMC of anti-HBs three years after vaccination was also significantly higher among those whose anti-HBs titer at T1 was 1 000-1 999 mU/ml, those whose anti-HBs titer at T1 was 2 000-2 999 mU/ml and those whose anti-HBs titer at T1 was ≥10 000 mU/ml. The b (95%CI) was 1.00 (0.87-1.14), 1.85 (1.74-1.97) and 3.28 (3.12-3.44), respectively. Four subjects showed HBsAg seroconversion and anti-HBc conversion rate was 4.68% at T2.

CONCLUSIONS

Anti-HBs GMC decreased rapidly three years after primary vaccination among normal and high-responder adults, while the positive rate of anti-HBs still kept at a high level. The anti-HBs persistence after primary vaccination was associated with HepB type, age and GMC of anti-HBs one month after vaccination.

[Anti-HBs persistence after revaccination with three doses of hepatitis B vaccine among non-responsive adults: a 4-year of follow-up study]

OBJECTIVE

To explore anti-HBs persistence four years after revaccination with hepatitis B vaccine (HepB) among adults who were non-responsive to HepB primary immunization.

METHODS

A total of 24 237 healthy adults who had no history of hepatitis B infection and hepatitis B vaccination, resided in the local area for more than six months and aged 18-49 years were selected from 79 villages of Zhangqiu County, Shandong Province, China in 2009. Blood samples were obtained and hepatitis B surface antigen (HBsAg), antibody against hepatitis B surface antigen (anti-HBs) and antibody against hepatitis B core antigen (anti-HBc) were detected using ELISA method. A total of 11 590 persons who were negative for all of these indicators were divided into four groups by cluster sampling methods. Each group was vaccinated with one of the following four types of HepB at 0-1-6months schedule: 20 μg HepB derived in Saccharomyces cerevisiae (HepB-SC), 20 μg HepB derived in Chinese hamster ovary cell (HepB-CHO), 10 μg HepB-SC and 10 μg HepB derived in Hansenula polymorpha (HepB-HP). Blood samples were collected one month after the third dose of primary immunization and tested for anti-HBs using chemiluminescence microparticle immunoassay (CMIA). The non-responders were followed up and their basic information and the histories of hepatitis B infection, HepB vaccination, smoking and drinking were investigated. Then they were revaccinated with three doses of HepB with the same schedule as the primary immunization. Blood samples were collected from all of them one month (T1), two years and four years after revaccination and anti-HBs, anti-HBc and HBsAg were detected by CMIA. A total of 356 participants were followed up from 645 low-responders four years after revaccination, and the ratio was 55.2%. The risk factors associated with the positive rate and geometric mean concentration (GMC) of anti-HBs after four years of revaccination were analyzed using multivariate unconditional logistic regression model and multivariate linear regression model, respectively.

RESULTS

Among 356 participants, 172 (48.3%) were males and 184 (51.7%) were females. The anti-HBs positive rate was 90.4% (322 cases) at T1 and was 55.9% (199 cases) four years after revaccination. The GMC of anti-HBs was 240.5 (95% CI: 186.4-310.4)mU/ml at T1 and decreased to 15.0 (95%CI: 12.2-18.5) mU/ml four years after revaccination. The average annual decreasing rate of GMC was 50.63% from one month after revaccination to four years after revaccination. The corresponding rate was 64.89% in the first two years, which was 2.12 times the rate in the latter two years (30.57%). When compared with those whose anti-HBs titer was less than 99 mU/ml at T1, the significantly higher anti-HBs four years after revaccination was observed in those whose anti-HBs titer at T1 was 100-999 mU/ml and those whose anti-HBs titer at T1 was ≥1 000 mU/ml. The OR (95%CI) was 7.14 (3.90-13.05) and 28.40 (13.16-61.30) respectively. When compared with those whose anti-HBs titer was ≤99 mU/ml at T1, the GMC of anti-HBs four years after revaccination was also significantly higher among those whose anti-HBs titer at T1 was 100-999 mU/ml and those whose anti-HBs titer at T1 was ≥1 000 mU/ml. The b (95%CI) was 1.66 (1.26-2.05) and 3.16 (2.72-3.60), respectively.

CONCLUSION

The positive rate and GMC of anti-HBs decreased four years after revaccination among non-responsive adults, but still kept anti-HBs above protective level. The immunity durability after revaccination is mainly associated with anti-HBs titer one month after revaccination.

[Antibody persistence following primary vaccination with hepatitis B vaccine among normal and high-responder adults: a 5-year follow-up study]

OBJECTIVE

To evaluate the 5-year antibody persistence and the risk factors associated with the persistence after primary vaccination of hepatitis B vaccine (HepB) among normal or high-response adults.

METHODS

A total of 24 237 healthy adults who had no histories of hepatitis B infection and hepatitis B vaccination, resided in the local area for more than six months and were aged 18-49 years were selected from 79 villages in north of Zhangqiu county, Shandong province, China in 2009. Blood samples were obtained and hepatitis B surface antigen (HBsAg), antibody against hepatitis B surface antigen (anti-HBs) and antibody against hepatitis B core antigen (anti-HBc) were detected using ELISA method. A total of 11 590 persons who were negative for all of these indicators were divided into four groups by cluster sampling methods. Each group was vaccinated with one of the following four types of HepB at 0-1-6 months schedule: 20 μg HepB derived in Saccharomyces cerevisiae (HepB-SC), 20 μg HepB derived in Chinese hamster ovary cell (HepB-CHO), 10 μg HepB-SC and 10 μg HepB derived in Hansenula polymorpha (HepB-HP). The normal and high-responder was followed up and their demographic characteristic (including age, gender), histories of hepatitis B infection, hepatitis B vaccination, smoking, drinking and chronic diseases were investigated. Blood samples were collected one month (T1) and five years (T2) and anti-HBs, anti-HBc and HBsAg (if anti-HBs<10 mU/ml) were detected by CMIA. A total of 1 902 participants were followed up and the risk factors associated with positive rate of anti-HBs and GMC of anti-HBs were identified by multiple logistic regression analysis and multifactor linear regression model analysis, respectively.

RESULTS

Among 1 902 adults, 824 (43.32%) were male and 1 078 (56.68%) were female. The anti-HBs positive rate was 100% at T1 and it decreased to 73.29% (1 394 cases) at T2. The corresponding GMC was decreased from 1 527.15 (95%CI: 1 437.84-1 622.01) mU/ml at T1 to 35.07 (95%CI: 32.20-38.19) mU/ml at T2. When comparing with those vaccinated 20 μg HepB-SC, the significantly lower positive rate at T2 was observed in those vaccinated 10 μg HepB-SC group and 10 μg HepB-HP group. The OR (95% CI) was 0.41 (0.28-0.61) and 0.27 (0.18-0.39), respectively. The GMC of anti-HBs was also significantly lower among those vaccinated 10 μg HepB-SC and 10 μg HepB-HP. The b (95%CI) was -0.20 (-0.28- -0.12) and -0.36 (-0.44- -0.29) , respectively. When comparing with those occasionally drinking, the significantly lower positive rate at T2 was observed in those regular drinking. The OR(95%CI) was 0.51(0.30-0.87). The GMC of anti-HBs in age group of 18-29 was significantly higher than those in 40-49 age group; the b (95%CI) was -0.10(-0.18- -0.01). When comparing with those whose anti-HBs titer was less than 999 mU/ml at T1, the significantly higher positive rate of anti-HBs at T2 was observed in those whose anti-HBs titer was 1 000-1 999 mU/ml, those whose anti-HBs titer was 2 000-2 999 mU/ml and those whose anti-HBs titer was ≥10 000 mU/ml. The OR (95%CI) was 10.11 (6.90-14.82), 20.42 (13.98-29.82) and 54.58 (22.08-134.92), respectively. When comparing with those whose anti-HBs titer was ≤999 mU/ml at T1, the GMC of anti-HBs at T2 was also significantly higher among those whose anti-HBs titer at T1 was 1 000-1 999 mU/ml, those whose anti-HBs titer at T1 was 2 000-2 999 mU/ml and those whose anti-HBs titer at T1 was ≥10 000 mU/ml. The b (95%CI) was 0.55 (0.47-0.62), 0.94 (0.88-1.00) and 1.63 (1.54-1.72), respectively. Nobody was found positive to HBsAg at T2 and the conversion rate of anti-HBc was 3.89% (74/1 902) at T2.

CONCLUSION

Anti-HBs GMC decreased rapidly at T2 among normal and high-responder adults, while the positive rate of anti-HBs still kept at a high level. The antibody persistence among normal and high-responder adults at T2 was associated with HepB type, age, history of drinking and GMC of anti-HBs at T1.

[Anti-HBs persistence following revaccination with three doses of hepatitis B vaccine among low-responsive adults after primary vaccination: a 4-year follow-up study]

OBJECTIVE

To assess the 4-year anti-HBs persistence after revaccination with 3-dose of hepatitis B vaccine (HepB) among low-responsive adults.

METHODS

A total of 24 237 healthy adults who had no history of hepatitis B infection and hepatitis B vaccination, resided in the local area for more than six months and were aged 18-49 years were selected from 79 villages of Zhangqiu county, Shandong province, China in 2009. Blood samples were obtained and hepatitis B surface antigen (HBsAg), antibody against hepatitis B surface antigen (anti-HBs) and antibody against hepatitis B core antigen (anti-HBc) were detected using ELISA method. A total of 11 590 persons who were negative for all of these indicators were divided into four groups by cluster sampling method. Each group was vaccinated with one of the following four types of HepB at 0-1-6 months schedule: 20 μg HepB derived in Saccharomyces cerevisiae (HepB-SC), 20 μg HepB derived in Chinese hamster ovary cell (HepB-CHO), 10 μg HepB-SC and 10 μg HepB derived in Hansenula polymorpha (HepB-HP). Blood samples were collected one month after the third dose of primary immunization and tested for anti-HBs using chemiluminescence microparticle immunoassay (CMIA). The 892 low-responders were revaccinated with three doses of HepB at 0-1-6 months schedule and the type of HepB was the same as which was used for primary immunization. During the follow-up to low-responders, the following informations were collected: the demographic characteristics (including age, gender), histories of hepatitis B infection, hepatitis B vaccination, smoking, drinking and chronic diseases. Blood samples were collected one month (T1) and four years after revaccination and anti-HBs, anti-HBc and HBsAg (if anti-HBs <10 mU/ml) were detected by CMIA. The risk factors associated with positive rate of anti-HBs and GMC of anti-HBs were identified by multiple logistic regression analysis and multifactor linear regression model analysis respectively. Anti-HBs titer at T1 was grouped according to the level and was considered as the independent variable in the model analysis.

RESULTS

A total of 529 participants were identified from 892 low-responders. Among 529 participants, 276 (52.2%) were males and 253 (47.8%) were females. The positive rate was 82.6% (437/529) at T1 and it decreased to 28.2% (149/529) four years after revaccination. The corresponding GMC decreased from 542.06 (95% CI: 466.72-629.56) mU/ml to 27.69 (95% CI: 23.08-33.23) mU/ml. Multivariable analysis showed the positive rate of anti-HBs 4 years after revaccination was independently associated with anti-HBs titer at T1. The positive rate among those whose anti-HBs titer more than 1 000 mU/ml at T1 was significantly higher than those whose anti-HBs titer less than 100 mU/ml. The OR (95%CI) was 39.67 (13.81-114.01). The GMC was associated with HepB type for revaccination and anti-HBs titer at T1. The GMC among those revaccinated 20 μg HepB was significantly higher than those revaccinated 20 μg HepB-CHO, 10 μg HepB-SC and 10 μg HepB-HP. The b (95% CI) was -0.40 (-0.78--0.02), -0.57 (-1.01- -0.15) and -0.63 (-1.03- -0.23), respectively. The GMC among those whose anti-HBs titer 100-999 mU/ml and those whose anti-HBs titer ≥1 000 mU/ml at T1 were higher than those whose anti-HBs titer <100 mU/ml. The b (95% CI) was 0.93 (0.53-1.33) and 3.31 (2.88-3.73) respectively.

CONCLUSION

Anti-HBs GMC decreased rapidly 4 years after revaccination among low-responsive adults, but still kept good protecion. The anti-HBs persistence after revaccination was associated with HepB type for revaccination and anti-HBs level of titer one month after revaccination.

An outbreak following importation of wild poliovirus in Xinjiang Uyghur Autonomous Region, China, 2011

Background

After more than 10 years without a case of wild poliovirus (WPV) in China, an outbreak occurred in 2011 in Xinjiang Uyghur Autonomous Region.

Methods

Acute flaccid paralysis (AFP) case surveillance was strengthened with epidemiological investigations and specimen collection and serological surveys were conducted among hospitalized patients.

Results

There were 21 WPV cases and 23 clinical compatible polio cases reported. WPV was isolated from 14 contacts of AFP cases and 13 in the healthy population. Incidence of WPV and clinical compatible polio cases were both highest among children <1 years, however, 24/44 (54.5%) polio cases were reported among adults aged 15–39 years.

Conclusions

High coverage of routine immunization should be maintained among children until WPV transmission is globally eradicated. Expansion of AFP case surveillance and use of serologic surveys to estimate population immunity should be conducted rapidly to guide preparedness and response planning for future WPV outbreaks.

Comparison between the EQ-5D-5L and the EQ-5D-3L in patients with hepatitis B

OBJECTIVES

The purpose of the study was to compare psychometric properties of the EQ-5D-5L (5L) and the EQ-5D-3L (3L) health outcomes assessment instruments in patients with hepatitis B in China.

METHODS

Patients, including hepatitis B virus carriers and those with active or inactive chronic hepatitis B, compensated cirrhosis, decompensated cirrhosis or hepatocellular carcinoma, answered a questionnaire composed of 5L, socio-demographic information, 3L, and the visual analog scale (VAS), respectively. After 1 week, a retest was conducted for inpatients. We compared acceptability, face validity, redistribution properties, convergent validity, known-group validity, discriminatory power, ceiling effect, test-retest reliability, and responsiveness of 5L and 3L.

RESULTS

A total of 369 outpatients and 276 inpatients were recruited for the first interview. Of the inpatients, 183 were used in the retest. Most patients preferred 5L-3L. The 3L-5L response pairs had an inconsistency rate of 2.4%. Correlation with the VAS was greater with 5L than with 3L. Age, education, and comorbidity were associated with health-related quality of life (HRQoL). 5L discriminated more infectious conditions than 3L. In all dimensions, the Shannon's index from 5L was larger while in three dimensions the Shannon's evenness index from 5L was slightly larger. The ceiling effect was reduced in 5L. In patients with stable health states, no significant difference was detected in the weighted kappa between 5L and 3L, but intraclass correlation coefficient of 5L was higher than that of 3L. In patients with improved health states, HRQoL was seen as increased in both 5L and 3L, without significant difference.

CONCLUSIONS

The EQ-5D-5L was more suitable than the EQ-5D-3L in the patients with hepatitis B in China.

Enhanced surveillance of acute flaccid paralysis following importation of wild poliovirus in Xinjiang Uygur Autonomous Region, China

Background

After being polio free for more than 10 years, an outbreak occurred in China in 2011 in Xinjiang Uygur Autonomous Region (Xinjiang) following the importation of wild poliovirus (WPV) originating from neighboring Pakistan.

Methods

To strengthen acute flaccid paralysis (AFP) surveillance in Xinjiang, “zero case daily reporting” and retrospective searching of AFP cases were initiated after the confirmation of the WPV outbreak. To pinpoint all the polio cases in time, AFP surveillance system was expanded to include persons of all ages in the entire population in Xinjiang.

Results

Totally, 578 AFP cases were reported in 2011 in Xinjiang, including 21 WPV cases, 23 clinical compatible polio cases and 534 non-polio AFP cases. Of the 44 polio cases, 27 (61.4%) cases were reported among adults aged 15–53 years. Strengthening AFP surveillance resulted in an increase in the number of non-polio AFP cases in 2011 (148 children < 15 years) compared with 76 cases < 15 years in 2010. The AFP surveillance system in Xinjiang was sensitive enough to detect polio cases, with the AFP incidence of 3.28/100,000 among children < 15 years of age.

Conclusions

Incorporating adult cases into the AFP surveillance system is of potential value to understand the overall characteristics of the epidemic and to guide emergency responses, especially in countries facing WPV outbreak following long-term polio free status. The AFP surveillance system in Xinjiang was satisfactory despite limitations in biological sample collection.

Identification and control of a poliomyelitis outbreak in Xinjiang, China

BACKGROUND

The last case of infection with wild-type poliovirus indigenous to China was reported in 1994, and China was certified as a poliomyelitis-free region in 2000. In 2011, an outbreak of infection with imported wild-type poliovirus occurred in the province of Xinjiang.

METHODS

We conducted an investigation to guide the response to the outbreak, performed sequence analysis of the poliovirus type 1 capsid protein VP1 to determine the source, and carried out serologic and coverage surveys to assess the risk of viral propagation. Surveillance for acute flaccid paralysis was intensified to enhance case ascertainment.

RESULTS

Between July 3 and October 9, 2011, investigators identified 21 cases of infection with wild-type poliovirus and 23 clinically compatible cases in southern Xinjiang. Wild-type poliovirus type 1 was isolated from 14 of 673 contacts of patients with acute flaccid paralysis (2.1%) and from 13 of 491 healthy persons who were not in contact with affected persons (2.6%). Sequence analysis implicated an imported wild-type poliovirus that originated in Pakistan as the cause of the outbreak. A public health emergency was declared in Xinjiang after the outbreak was confirmed. Surveillance for acute flaccid paralysis was enhanced, with daily reporting from all public and private hospitals. Five rounds of vaccination with live, attenuated oral poliovirus vaccine (OPV) were conducted among children and adults, and 43 million doses of OPV were administered. Trivalent OPV was used in three rounds, and monovalent OPV type 1 was used in two rounds. The outbreak was stopped 1.5 months after laboratory confirmation of the index case.

CONCLUSIONS

The 2011 outbreak in China showed that poliomyelitis-free countries remain at risk for outbreaks while the poliovirus circulates anywhere in the world. Global eradication of poliomyelitis will benefit all countries, even those that are currently free of poliomyelitis.

[Effect of hepatitis health promotion project in schools of Beijing and Gansu]

OBJECTIVE

To evaluate effect of health promotion project of element school students in Beijing and Gansu.

METHODS

Evaluation field was conducted in 6 schools of hepatitis health promotion project. They were selected randomly from Beijing and Gansu, questionnaires were given to students and teachers for evaluating the awareness to hepatitis transmission and prevention, telephone interview was given to student's parents for awareness to hepatitis knowledge.

RESULTS

Awareness to hepatitis was increased after health promotion, knowledge of hepatitis A and hepatitis B transmission among element school students were increased from 46.95%, 32.26% at baseline to 98.92%, 96.42% at middle-term respectively. Awareness rate of prevention of hepatitis A and hepatitis B were increased from 67.03%,67.38% at baseline to 98.21%, 99.64% at middle-term respectively. Immunization coverage of hepatitis A and hepatitis B was 29.75% at baseline, and reached 77.06% at middle-term after health promotion. The parent's awareness rate of hepatitis transmission and prevention also increased to 85% and 99% after intervention.

CONCLUSION

It was very effective of health promotion project in two provinces, the improvement of awareness of hepatitis was not only for students, but also for parents as well.

[The immunogenicity and impact factors of hepatitis A attenuated live vaccine and inactivated vaccine]

Hepatitis A is one of the global public health problems, and China has high prevalence. In order to decrease the incidence of hepatitis A, China has integrated Hepatitis A vaccine into Expanded Program on Immunization (EPI) in 2007. The paper will provide some ideas on the immunogenicity and impact factors of the different types of hepatitis A vaccines that are used in China.

[Evaluation on impact of hepatitis B vaccine integrated into routine immunization in the areas of Ministry of Health/Global Alliance for Vaccine and Immunization (GAVI) Cooperation Project P.R. China]

OBJECTIVE

To evaluate the impact of hepatitis B vaccination after hepatitis B vaccine integrated into routine immunization in the areas of Ministry of Health/Global Alliance for Vaccine and Immunization GAVI Cooperation Project (MOH/GAVI Coopreation Project).

METHODS

Children born between 2002 and 2005 were selected from 68 counties of GAVI project by multi-stage random sampling method. Demographic information and hepatitis B vaccination history were collected by questionnaire and review of vaccination records, and 2-4ml serum sample was taken for testing of hepatitis B surface antigen (HBsAg), antibody to hepatitis B core antigen (Anti-HBc) and hepatitis B surface antibody (Anti-HBs) by Enzyme Linksed Immunosorbent Assay (ELISA) method.

RESULTS

Coverage of HepB3 and timely birth dose (HepB1) was 80.02% and 60.06% respectively, the younger, the higher. HepB coverage among children born in urban was higher than children born in rural, born in hospital was higher than born at home. The prevalence of HBsAg for children born between 2002-2005 was decreased to <2%.

CONCLUSION

HepB has been successfully integrated into routine immunization in GAVI project areas, the immunization coverage was improved dramatically.

[Combination profiles of hepatitis B marks for Chinese in serosurvey in 2006]

OBJECTIVE

To summarize the combination profile of hepatitis B markers by age and immunization history of Chinese.

METHODS

Population of age 1-59 years were sampled from 160 counties of National Disease Surveillance in 31 provinces by multi-stage random sampling method. Demographic information and hepatitis B vaccination history was collected by questionnaire, and 2-4ml serum sample was taken for testing HBsAg, Anti-HBs and Anti-HBc by ELISA method.

RESULTS

16 combinations of hepatitis B markers (HBsAg, Anti-HBs, Anti-HBc, HBeAg and Anti-HBe) were found during the testing, anti-HBs was mainly found among 1-4 years old children, accounted 69.77%. Among 15-59 years, negative markers were mainly profile. Among immunized population, the older, the lower rate of anti-HBs, while among un-immunized population, except negative for all markers and anti-HBs were observed, Infected markers was account for high proportion.

CONCLUSION

The profile could be used for guiding the laboratory testing by different epidemiologic characteristics, and can provide information for reference.

[Analysis on the adverse events following immunization of 10 infants death after hepatitis B vaccination]

OBJECTIVE

To evaluate the safety of Hepatitis B vaccine by analyzing the 10 infants death after Hepatitis B vaccination.

METHODS

Collect the reporting data from the public health emergencies report system of China Disease Prevention and Control System.

RESULTS

In the 10 death cases after hepatitis B vaccination, 2 cases would be acute anaphylactic shock caused by the vaccination, and the other 8 death cases were not related to vaccination.

CONCLUSIONS

The hepatitis B vaccine of China were safety, there were very few death cases of allergic reactions following hepatitis B vaccination. We should standardize the vaccination in order to reduce the adverse events following immunization.

[Analysis on the proportion of reported hepatitis B cases through pilot surveillance in China during 2006]

OBJECTIVE

To better understand the proportions of reported hepatitis B cases in pilot surveillance cites through investigation and laboratory testing.

METHODS

To confirm the reported cases of hepatitis B by collecting blood specimen and laboratory testing on HBsAg, IgM of Anti-HBc, Anti-HAV in 18 pilot surveillance counties.

RESULTS

Among 2858 cases of hepatitis B reported in 2006, 23.97% of them were reported as suspected acute cases, 14.87% as acute cases, 20.33% as suspected chronic cases, 34.67% as chronic cases, 4.09% as cirrhosis and 2.06% as HCC. Among 1681 reported hepatitis B cases confirmed by laboratory testing, results showed that 24.16% of them were diagnosed as acute hepatitis B, but only 15.37% were confirmed as acute hepatitis B. Although the proportion confirmed as hepatitis B kept consistent as before, misclassification was found.

CONCLUSION

In current surveillance system, reported hepatitis B cases were mainly chronic, only up to one third belonged to acute hepatitis B. The reported incidence of hepatitis B did not reflect the real incidence due to misclassification. To better define the burden on hepatitis B disease, it was necessary and urgent to revise the diagnostic criteria and to conduct surveillance on hepatitis B, under separate reporting categories which including acute and chronic cases of the disease.

Immunization coverage and its determinants in children aged 12–23 months in Gansu, China

The study aimed to assess the determinants of immunization coverage in 12-23-month-old children born in 1997 and living in Gansu Province in West China. The World Health Organization's cluster sampling technique was used. Information was gathered by face-to-face interviews with caregivers and from immunization records. Bacille Calmette Guerin (BCG), Polio and Diphtheria, Tetanus, Pertussis (DTP) coverage at 3 months was 51.2%. At 8 and 12 months, including the Measles Vaccine, coverage was 71.3 and 86.0%, respectively. The variables associated with delay at 12 months were: low socio-economic level, low number of sources of information on vaccination and delayed immunization at 3 months. Improved immunization coverage could be achieved by improving access and delivery to poor and remote areas and by awarding incentives to providers at primary care level.