Recent Trends in Sedentary Behaviors among Chinese Children According to Demographic and Social Characteristics.

OBJECTIVE: This study aims to explore trends in sedentary behavior among Chinese children aged 6-17 years per demographic and social characteristics. METHODS: A total of 4,341 children aged 6-17 years who participated in the China Health and Nutrition Survey from 2004 to 2015 were included. Repeated measures from mixed-effects models were applied to test trends in sedentary behaviors, which were further analyzed after applying stratification according to gender, age, urbanization level, residential area, and region. Random-effects ordinal regression models were used to examine the trends at sedentary levels. RESULTS: From 2004 to 2015, sedentary time among children aged 6-17 years increased from 23.9 ± 0.6 h/week to 25.7 ± 0.6 h/week ( P < 0.001). Increases of 3.1 h/week ( P < 0.001), 2.3 h/week ( P = 0.012), and 1.3 h/week ( P = 0.042) were found among the low-, medium-, and high-urbanization groups respectively and increased by 2.0 h/week ( P < 0.001) and 1.3 h/week ( P = 0.002) among rural and urban children, respectively. The proportion of Chinese children with average daily screen time below 2 hours declined by 10.2% ( OR = 0.51, 95% CI: 0.42-0.63, P < 0.001); a decreasing trend was observed in both boys and girls. CONCLUSIONS: Sedentary time among Chinese children aged 6-17 years showed an upward trend from 2004 to 2015, especially among children residing in rural areas and regions with low urbanization levels.

[Treatment of comminuted Neer IV fracture of proximal humerus with lower shoulder replacement assisted by 3D technique].

OBJECTIVE: To observe and compare the shoulder joint function, complications and clinical effects of hemiarthroplasty and open reduction and locking plate in the treatment of comminuted proximal humeral fracture (Neer IV) with 3D printing technique. METHODS: From March 2012 to April 2018, 31 middle age and elderly patients with comminuted proximal humeral fractures (Neer IV) were treated, including 4 males and 27 females, aged from 55 to 94 years old with an average age of 71 years, with a course of 1 to 3 years. Among them, 20 cases were treated with open reduction and locking plate internal fixation (ORIF group) and 11 cases were treated with lower half shoulder replacement (HA group) assisted by 3D printing technology. Using CT data and Mimics software of Materialise Company in Belgium, the reconstruction of fracture was simulated on computer. The height of fracture end to humeral head, the height of tubercle to humeral head, the angle of humeral head backward obliquity were measured to assist the hemiarthroplasty. Follow-up and X-ray examination were performed, the incidence of complications were observed, and Neer score was used for the shoulder joint function. RESULTS: Thirty-one patients were followed up for 1 to 3 years with an average of 2 years. In HA group, there was no prosthesis loosening, fracture and subsidence, the head of artificial humerus was intact, the fracture of nodules and nodules did not heal in 1 case, Neer score was 84.18±3.55; in ORIF group, there were 8 cases of proximal humerus bone resorption, 1 case of fracture nonunion, 1 case of internal fixation loosening, Neer score was 55.91±10.78; there was significant difference in Neer score of shoulder joint function between the two groups(P<0.05). CONCLUSIONS: Ultrasound-guided minimal traverse-cross technique repair for acute closed Achilles tendon ruptures, which promise minimal incision, protect sural nerve, ensure quality of tendon anastomosis and fixation, and is a ideal method for repairing acute closed Achilles tendon ruptures.

[Treatment of Pauwels type III femoral neck fractures with modified percutaneous compression plate].

OBJECTIVE: To investigate the preliminary effects of modified percutaneous compression plate in treating femoral neck fractures of Pauwels type III. METHODS: From March 2012 to March 2016, 35 patients with femoral neck fracture were treated by closed reduction and internal fixation with a modified percutaneous compression plate, including 21 males and 14 females with an average age of 45 years old ranging from 23 to 62 years old. The anatomical position of fracture was divided into 8 cases of lower head type, 27 cases of head and neck. According to the Garden classification, there were 8 cases of type II, 18 of type III, and 9 of type IV fractures. All patients were closed injury. The general information, reduction quality, fracture healing time, postoperative complications were recorded and evaluated. Harris scoring was used to evaluate the hip joint function. RESULTS: All patients were followed up for 15 to 24 months with an average of 20 months. All the incisions were primary healing. The reduction quality of the femoral neck fracture was evaluated according to the Garden's alignment Index, and the quality of reduction was grade I reduction in 29 cases and grade II reduction in 6 cases. No nonunion, femoral avascular necrosis, implant failure and hip varus was observed during follow-up. Harris score was(92.70±4.60) points at final follow-up, the results of the treatment was evaluated as excellent in 26 cases, good in 8 cases, fair in 1 case. No complications such as internal fixation loosening, nail breaking, and heterotopic ossification occurred. CONCLUSIONS: Internal fixation with modified percutaneous compression plate has an advantages of decreased trauma, simple operation, rigid fixation, good function outcome, and low risk of complications.

Prevalence and Predictors of Hypertension in the Labor Force Population in China: Results from a Cross-sectional Survey in Xinjiang Uygur Autonomous Region.

The objective of this study was to examine the prevalence of hypertension and identify its contributory factors in the labor force population in Karamay. A total of 2819 adults (55.9% male adults) were interviewed and examined. The overall crude prevalence of hypertension was 32.4%. Among 914 hypertensive patients, 34.8% were aware of their diagnosis, 22.1% received treatment, and 5.6% achieved blood pressure control. Hypertension was significantly correlated with age, overweight/obesity, central obesity, diabetes, and dyslipidemia in both men and women. In addition, less education, alcohol consumption, and less walking were risk factors for men. Effective hypertension prevention and control programs are urgently needed to decrease the burden of hypertension in this region.

[Design of the reduction fixator and its clinical application in treating fracture of lesser trochanter of femur].

OBJECTIVE: To discuss the clinical significance of the reduction and fixation for femoral lesser trochanteric fragment in treating the femoral comminuted intertrochanteric fractures. METHODS: From January 2012 to December 2013,32 patients with intertrochanteric fractures were treated by surgery, and self-designed reduction fixators were used in the patients for the fixation of lesser trochanter of femur. There were 11 males and 21 females, ranging in age from 45 to 81 years old with an average of 64 years old. According to the Evans typing, 12 cases were type II, 13 cases were type III and 7 cases were type IV. Simple lag screw fixed in 19 cases and steel wire fixed in 13 cases. Hip joint function was evaluated according Harris score and the complications such as coxa adducta,cutting of femoral head and neck,implants breakage were observed. RESULTS: Thirty-two patients were followed up from 9 to 24 months with an average of 13 months. Coxa adducta occurred in 1 case,no cutting of femoral head and neck occurred and implants breakage were found. The mean Harris score was 91.80 ± 3.05 in 32 patients. CONCLUSION: The reconstruction and fixation for the posterior medial bone cortex continuity is a key factor on affect the stability of femoral intertrochanteric fracture. Self-designed reduction fixators can effective reduce and fix the lesser trochanter of femur, it has advantage of fast reduction and fixation, and simple operation.

[Operative treatment for proximal humeral fracture with rotator cuff tear in elderly patients].

OBJECTIVE: To explore operative clinical outcomes of proximal humeral fracture with rotator cuff tear in elderly patients. METHODS: From March 2010 to August 2014,54 elderly patients with proximal humeral fractures with rotator cuff tear were performed operation, including 30 males and 24 females aged from 68 to 83 years old with an average of 71.5 years old. Thirty patients were caused by falling down, 24 cases were caused by traffic accident. According to Neer classification, 3 cases were part I, 11 cases were part II, 21 cases were part III and 19 cases were part IV. All patients were operated with open reduction and plate internal fixation, 46 cases suffered from rotator cuff tear and carried out repair of rotator cuff; 8 cases were not suffered from rotator cuff tear. Postoperative Neer evaluation of shoulder's function were used to assess clinical results. RESULTS: Forty-six patients with rotator cuff tear were followed up from 8 to 21 months with an average of 11 months. All fractures were obtained bone union. No incision infection, axillary nerve injury,loosening screw, plate breakage, shoulder joint dislocation and humeral head osteonecrosis were occurred. According to Neer evaluation of shoulder's function, total score was 88.60 ± 5.12, and 30 cases got excellent results, 7 cases good, 7 cases moderate and 2 cases poor. CONCLUSION: For osteoporotic proximal humeral fractures with rotator cuff tear in elderly patients' plate with rivet repair at stage I is an effective stable method, and provide advantages for earlier exercise of shoulder joint, then receive good clinical effects in further.

Sero-survey of polio antibodies during wild poliovirus outbreak in southern Xinjiang Uygur Autonomous Region, China.

BACKGROUND: After being polio free for more than 10 years, an outbreak following importation of wild poliovirus (WPV) was confirmed in Xinjiang Uygur Autonomous Region, China, in 2011. METHODS: A cross-sectional study was conducted prior to supplementary immunization activities (SIAs), immediately after the confirmation of the WPV outbreak. In selected prefectures, participants aged ≤ 60 years old who visited hospitals at county-level or above to have their blood drawn for reasons not related to the study, were invited to participate in our study. Antibody titers ≥ 8 were considered positive. RESULTS: Among the 2,611 participants enrolled, 2,253 (86.3%), 2,283 (87.4%), and 1,989 (76.2%) were seropositive to P1, P2 and P3 respectively, and 1744 (66.8%) participants were seropositive to all the three serotypes. Lower antibody seropositivities and geometric mean titers were observed in children <1 year of age and in adults aged 15-39 years. CONCLUSION: Serosurveys to estimate population immunity in districts at high risk of polio importation might be useful to gauge underlying population immunity gaps to polio and possibly to guide preparedness and response planning. Consideration should be given to older children and adults during polio risk assessment planning and outbreak response.

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.

[Study on the risk of HBV infection among spouses of HBsAg carriers].

OBJECTIVE: To investigate the risk of HBV infection among the spouses of hepatitis B virus surface antigen (HBsAg) carriers and to provide a reference for developing strategies on hepatitis B control and prevention. METHODS: A case-control study including HBsAg carriers aged 20 - 45 years-old from the nationwide sero-epidemiological survey for Hepatitis B in both Guangdong and Jiangxi provinces in 2006, together with their spouses were selected as case group, while. HBsAg negative persons and their spouses were among the control groups, under the same residential areas, gender, age and age of marriage to the HBsAg carriers. Questionnaire survey and hepatitis B serological markers detection were carried out, together with the HBV genotype detection among the HBsAg positive couples between husband and wife by PCR. RESULTS: Among the spouses of HBsAg carriers, the positive rate of HBsAg was 13.21%, while the rate was 6.29% for the spouse of HBsAg negative population, with difference statistically significant (χ² = 4.23, P < 0.05). HBsAg positive rate among spouses of the case group was higher than that in the control group. Among the spouses of HBsAg carriers, the HBsAg rate was positively correlated with the age of marriage, frequency of sexual intercourse and condom use. There were 21 pairs of HBsAg carriers between husband and wife, and HBV were isolated among 13 pairs, and there were 11 pairs carrying the same HBV genotype, accounting for 84.62%. HBV genotypes would include 8 pairs of type B and 3 pairs of type C. However, only 2 pairs were infected with different HBV genotype. CONCLUSION: High risks of HBV infection existed in the spouses of HBsAg carriers. It was important to ask the HBsAg carriers to take the initiative in informing their spouses, and carrying out the appropriate measures, such as safe sex or timely hepatitis B vaccination for the spouse of HBsAg carriers etc., so as to reduce the HBV transmission between husband and wife.

Geographic variation in diapause induction and termination of the cotton bollworm, Helicoverpa armigera Hübner (Lepidoptera: Noctuidae).

Overwintering diapause in Helicoverpa armigera, a multivoltine species, is controlled by response to photoperiod and temperature. Photoperiodic responses from 5 different geographical populations showed that the variation in critical photoperiod for diapause induction was positively related to the latitudinal origin of the populations at 20, 22 and 25°C. Diapause response to photoperiod and temperature was quite different between northern and southern populations, being highly sensitive to photoperiod in northern populations and temperature dependence in southern populations. Diapause pupae from southern population showed a significantly shorter diapause duration than from northern-most populations when they were cultured at 20, 22, 25, 28 and 31°C; by contrast, overwintering pupae from southern populations emerged significantly later than from northern populations when they were maintained in natural conditions, showing a clinal latitudinal variation in diapause termination. Diapause-inducing temperature had a significant effect on diapause duration, but with a significant difference between southern and northern populations. The higher rearing temperature of 22°C evoked a more intense diapause than did 20°C in northern populations; but a less intense diapause in southern population. Cold exposure (chilling) is not necessary to break the pupal diapause. The higher the temperature, the quicker the diapause terminated. Response of diapause termination to chilling showed that northern populations were more sensitive to chilling than southern population. All results demonstrate that H. armigera is not genetically homogeneous throughout its range, but rather is composed of distinct populations genetically adapted to local environmental conditions despite the potential for gene flow via seasonal migration of adults.

Inheritance of photoperiodic control of pupal diapause in the cotton bollworm, Helicoverpa armigera (Hübner).

Pupae of the cotton bollworm, Helicoverpa armigera display a diapause in response to the exposure of their larvae to short photoperiods and relatively low temperatures. Due to geographic variation in photoperiodic response, moths from a northern population, Langfang (39°32'N, 116°41'E), enter diapause in response to short daylengths (D strain) while moths from a southern population, Ledong (18°28'N, 108°53'E), exhibit no diapause under the same conditions (N strain). In the present study, crosses between the two strains are utilized to evaluate the inheritance of diapause under different photoperiods at temperatures 20, 22 and 25°C. The moths in both reciprocal crosses and backcrosses to D strain showed a clear long-day response, similar to that of the D strain, suggesting that the photoperiodic response controlling diapause in this moth is heritable. The incidences of diapause for all F(1) hybrids were intermediate between those of their parents. However, the incidences of diapause at 20°C in F(1) (N×D) strain were significantly higher than those in F(1) (D×N) strain, indicating that the male parent plays a more important role in the determination of diapause. The N strain also showed a short-day photoperiodic response at the lower temperature of 20°C, indicating that the N strain still has the capability to enter a photoperiodically induced diapause, depending on the rearing temperature. Results from all crosses under photoperiods LD 12:12 or LD 13:11 at 22°C showed that inheritance of diapause in H. armigera did not fit an additive hypothesis and that the capacity for diapause was transmitted genetically in the manner of incomplete dominance with non-diapause characteristic partially dominant over the diapausing. Diapause duration in hybrid pupae was also influenced by their inheritance from both parents. Diapause duration in hybrid pupae was intermediate between those of their parents. These results reveal that both diapause induction and duration are under the control of polygene.

[A sero-epidemiological study on hepatitis C in China].

OBJECTIVE: To better understand and measure the status of hepatitis C virus (HCV) infection, we conducted a sero-epidemiological study using the remaining blood samples and data of the nationwide survey of hepatitis B in Chinese residents which was carried out in 2006. METHODS: The anti-HCV reagent was screened out from the reagents by the HCV infection blood serum plate with anti-HCV positives or negatives. This plate recognized the Murex 3.0 and Ortho 3.0 reagents as gold standards. Anti-HCV in the blood samples were tested using this reagent and confirmed by Chiron HCV RIBA 3.0 reagents. RESULTS: Among the population aged 1 year to 59 year-olds, the overall prevalence rate of anti-HCV was 0.43% (95%CI: 0.33% - 0.53%), with the rates of anti-HCV among males and females as 0.46% and 0.40%, respectively. The prevalence rate of anti-HCV in urban area was 0.43%, and in rural area it was 0.43%. The prevalence rate of anti-HCV in the Eastern, Middle and Western areas were 0.37% (95%CI: 0.21% - 0.53%), 0.67% (95%CI: 0.40% - 0.94%) and 0.31% (95%CI: 0.20% - 0.42%) respectively. The prevalence rates of anti-HCV for the three areas did not show significant differences, statistically. The prevalence rate of anti-HCV in the South and North areas were 0.29% (95%CI: 0.21% - 0.52%) and 0.53% (95%CI: 0.38% - 0.64%) respectively. CONCLUSION: Our data revealed that China was in the low prevalence area for hepatitis C infection and the results also suggested that the comprehensive measures for HCV control and prevention had been successfully achieved in the country.

[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.

[The serum markers of hepatitis B virus (HBV) infection and the natural history of chronic HBV infection].

The serum markers of hepatitis B virus (HBV) infection are complex, mainly including HBV surface antigen (HBsAg) and antibody to HBsAg, HBV e antigen (HBeAg) and antibody to HBeAg, antibody to HBV core antigen. The natural history of chronic HBV infection is complex and variable and greatly influenced by the age of infection, the level of HBV replication, HBV genotype and mutations, presence of HBeAg, ALT level, coinfection with HCV and/or HDV, host immune status. Four stages of chronic HBV infection are the immune tolerant phase, the immune clearance phase, the low or non-replicative phase, and the reactivation phase. Some patients with HBeAg positive, high level of ALT and HBV DNA>105 copies/mL would develop liver-related complications, such as cirrhosis, hepatocellular carcinoma and liver failure. Available evidences indicate that control of HBV replication with antiviral drugs can decrease the incidence of these complications and mortality.

[Study on the probability of hepatitis B virus infection at public service places].

OBJECTIVE: To provide data for the control and prevention of hepatitis B and HBV surface antigen (HBsAg) status among the appliances and practitioners working in the public service places. METHODS: 63 beauty parlors, barber shops and bathing centers selected under stratified randomization sampling method and 682 workers were investigated through questionnaire. HBsAg from th e appliances of the public service places and employee was detected by RIA. RESULTS: Two main sanitizing modes that including alcohol cleaning (34.60%) and ultraviolet light disinfection (30.79%) were used. The rates of testing on HBsAg among the appliances were 2.13% at the public service places, and were 0.63%, 2.67% and 3.70% in large-, medium- and small-sized appliances respectively. The rate of testing on HBsAg on large-, medium- and small- sized appliances were statistically different (chi2 = 6.68, P < 0.05). The positive rates of HBsAg on the appliances of beauty parlors, barbering shops and footbath inns were 2.97%, 0.61% and 3.42% respectively. People working in different service sites had different rates of HBsAg: those who worked at the 'acne needle' and the forceps were 5.13% and 4.17%. The positive rate of HBsAg among the workers in the public service places was 7.13%. The rates of HBsAgamong the workers in large-, medium- and small-sized public service places were 7.34%, 8.33% and 2.94% respectively. The rates of HBsAg among the workers in beauty parlors, barbering shops, footbath inns and bathing centers were 9.01%, 6.37%, 4.35% and 7.29% respectively. HBsAg positive rates were different among the workers working at different service sites: 13.33% at tattoo business, 12.68% in pedicles workers and 8.03% in massagists. CONCLUSION: It is important to improve the sanitizing management of the appliances used in the public service places and to improve the knowledge, attitude, as well as practice of vaccination on hepatitis B among those populations.

[Study on the immunity of diphtheria in children at county level with different 4-vaccine coverage rates based on the results from "National Immunization Program Review" in 2004].

OBJECTIVE: To investigate the immunity level of diphtheria antibody among children living in the areas where different coverage rates of 4-vaccines stratified by results of national immunization program (NIP) reviewed in 2004. METHODS: According to data from 4-vaccine coverage rates of NIP reviewed in 2004, 3 levels could be set. We randomly selected 2 counties at each level and then 10 villages from each county with 42 children involved who were born between 1992 and 2003. ELISA quantitative method was used to test IgG of diphtheria antitoxin. RESULTS: (1) The positive rate of diphtheria antitoxin was only 49.6% with the highest as 78.1% and lowest as 33.0%. There was a significant decreasing trend of this positive rate with the increase of age. The highest (61.2%) fell in the group that were born in 2003 and the lowest (37.6%) was seen among children born in 1992 to 1995. (2) Geometric mean concentrations (GMCs) was only 0.48 IU/ml with a trend of decrease when age was increasing. There was no GMCs peak seen in children who were at the age of boosting, as expected. (3) Positive rates of children born between 2001 and 2003 were lower than 62% while the diphtheria-pertussis-tetanus (DPT) vaccine coverage rates were all higher than 90%. (4) There was no significant difference of diphtheria antitoxin positive rates between children with eligible routine immunization (58.1%) and those were ineligible (59.6%). CONCLUSION: Other than some specific ones, children from most of the investigated counties had a low level of antibody against diphtheria. The coverage rate of DPT vaccine did not necessarily reflect the immunity against diphtheria, suggesting the increase of immunity against diphtheria an urgent task to be taken care of.

[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.

[A study on the sero-epidemiology of hepatitis B in Chinese population aged over 3-years old].

OBJECTIVE: To better understand and measure the impact from immunization activities over the last 10-years, we conducted a sero-epidemiological study using the remaining blood samples of a nationwide survey on Nutrition and Health in Chinese residents, in 2002. METHODS: HBsAg, anti-HBs and anti-HBc in blood samples were tested using enzyme-linked immunosorbent assay(ELISA) reagents and revised by solid phase radioimmunoassay and Abbott ELISA reagents. RESULTS: Among population older than 3 years, the prevalence rates of HBsAg, anti-HBs and hepatitis B virus(HBV) infection were 9.09%, 37.48% and 50.04% but for children between 3 and 12 year olds, they were 5.03%, 45.33% and 29.10% respectively. Among population older than 3 years, the rates of HBsAg and HBV infection in urban area were 4.61% and 43.51%, but the rates in rural area were 9.41% and 56.77% respectively while for children from 3-years to 12-years old, they rates were 2.10%, 20.45% in urban area and 8.25%, 39.22% in rural areas, respectively. CONCLUSION: Results revealed that since the hepatitis B vaccine was introduced into the expanded program on immunization(EPI) from 1992, the prevalence rates of HBsAg and HBV infection, especially in the children from 3 to 12 years of age, had obviously declined, suggesting that some changes had happened in the epidemic characters of hepatitis B in China.