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@#Abstract: Objective To establish the duplex TaqMan RT-PCR method for detection of Entamoeba histolytica and Giardia lamblia in fecal samples. Methods Primer pairs and probes for Entamoeba histolytica and Giardia lamblia were designed and duplex TaqMan RT-PCR amplification system was constructed. PCR products were inserted into the pUC57 plasmid, and the lower limit of detection of the method was determined. Clinical stool samples were tested in order to evaluated the efficacy of the method. Results The detection limits of duplex TaqMan RT-PCR were 31.6 copies/μL for Entamoeba histolytica and 32 copies/μL for Giardia lamblia, respectively. Of the total of 212 clinical stool samples tested, all 3 samples with E. histolytica-positive patients by microscopy were positive by PCR, while 1 from 209 samples with E. histolytica-negative patients by microscopy were positive by PCR, and the remaining samples were negative. For Giardia lamblia, all 8 samples positive by microscopy were positive by PCR, and 1 from 204 sample with a microscopy-negative patient was positive by PCR, and the remaining samples were negative. The amplification product sequencing and blast analysis were used to confirm that the amplified sequence in the specimen of a patient with negative microscopy but positive PCR belongs to the targeted pathogen, supported by clinical symptoms and laboratory test results. PCR results for other diarrhea-causing pathogens were negative, indicating no cross-reactivity. Conclusions The dual TaqMan RT-PCR method developed in this study can not only detect microscopy-positive samples of Entamoeba histolytica and Giardia lamblia but also can detect samples that were missed by microscopy, with higher sensitivity than the microscopy method. Further, this detection method does not cross-react with other diarrhea-causing pathogens, including cross-react with other diarrhea-causing pathogens including Iodamoeba butschlii, Blastocystis hominis, Plesiomonas, Aeromonas, Salmonella, Shigella, Sphaerozoum fuscum, and Entamoeba hartmani, thus has a good specificity.
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@#Abstract: Objective To find out the existing problems and provide reference for further improving the quality of report information by analyzing the report cards of COVID-19 and the positive report cards of primary screening reported in Ningxia. Methods All COVID-19 case cards from 2020 to 2021 and initial screening positive cards were derived from the Chinese Information System for Disease Control and Prevention according to final review date. The timeliness of case reporting, timeliness of case review, completeness and accuracy of the case cards were analyzed. Results In Ningxia, the first case of COVID-19 was reported on January 20, 2020, and as of December 31, 2021, 122 confirmed cases and 4 symptomatic infected cases were reported. In 2021, the timely reporting rate of COVID-19 was 98.00%, which increased by 8.24% compared with 2020 (90.54%). Compared with 2020, the average time limit for diagnosis to reporting of COVID-19 in 2021 was shortened by 83.12%; in 2021, the timely review rate of COVID-19 was 100.00%, which increased by 13.84% compared with 2020 (87.84%). Compared with 2020, the time from reporting to final review was shortened by 98.91%. In 2021, the timely rate of positive reports in COVID-19 in Ningxia was 90.00%, among which the timely rate of reports by county (district) nucleic acid detection institutions was the highest (92.31%), followed by municipal (91.67%) and autonomous region (81.82%). Conclusions At the beginning of the epidemic in 2020, the timeliness of COVID-19 in Ningxia was poor, and through the implementation of measures such as technical training, supervision and inspection to continuously optimize the staffing of medical institutions and disease control institutions, the timeliness of reporting COVID-19 in Ningxia in 2021 was substantially improved, but there were still some weak links. In the future work, technical guidance and training should be carried out for weak links, and efforts should be made to improve the quality of reports.
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Objective@#To analyze household determinants of adolescents non suicidal self injury(NSSI), and to provide scientific basis for NSSI intervention amogn adolescents.@*Methods@#Using stratified random cluster sampling method, 15 623 middle school students aged 11-20 were selected from Heilongjiang, Anhui, Hubei, Yunnan, and Guangdong provinces, and non suicidal self injury and related household determinants were investigated by questionnaire.@*Results@#The survey showed that 28.8% of people who had NSSI in the past year accounted;among them,17.6% had 1-4 times(occasional self injury) and 11.2% had 5 times or more(repeated self injury) univariate results showed that whether they were an only child, family type, educational level of the main caregiver, family rearing style, family monthly income per capita, and whether there was a family history of mental illness was associated with adolescents NSSI ( χ 2=6.30-12.16, P <0.05); multivariate Logistic regression analysis showed that whether one child or family parenting style is still significantly related to occasional NSSI( OR =1.11,1.34, P <0.05)after controlling for gender, age, grade, ethnicity, emotional control, resilience, loneliness and social support; whether it is an only child, educational level of the main caregiver and family parenting style are still significantly related to repeated NSSI ( OR =1.19，0.69，1.57， P <0.05); stratified analysis by region shows that the influencing factors of NSSI in adolescents in each region are different.@*Conclusion@#Family factors such as the only child and the education level of the main caregiver may be related to the occurrence of adolescents NSSI, but there are regional differences in the family impact of NSSI.
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Objective@#To explore the association between aggression and social support and their gender differences among Chinese adolescence, and to provide a scientific reference for preventing and reducing aggressive behaviors of adolescents.@*Methods@#Conducted a cross sectional survey of 15 623 adolescents in 5 provinces in China, namely, HeiLongjiang, Hubei, Anhui, Guangdong and Yunnan Province. And the Chinese version of the Adolescent Social Support Scale was employed to assess the aggression and social support, life events, psychological characteristics, family condition and demographic characteristics among adolescents.@*Results@#The prevalence of self reported high level of aggression was 23.5%(3 670/15 623). Males reported higher rate of high level aggression than females (24.4% vs 22.5%, χ 2=19.30, P <0.01). Significant association between aggression and social support was identified in univariate analysis ( χ 2=620.68, P <0.01). After controlling for potential confounders, aggression was also significantly negatively associated with social support ( OR =1.27-1.84), and there was dose response relationship between them( P < 0.05 ). Furthermore, the association between aggression and social support was similar among male participants and female participants ( ROR =1.02-1.10, P >0.05).@*Conclusion@#The findings indicate that aggression is associated with social support both in male and female adolescents. Improving the social support for adolescents can reduce their aggressive behaviors.
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Objective@#To analyze the association between masculine and feminine traits, gender role in students and family factors, and to provide a scientific basis for promoting the healthy development of children and adolescents gender role.@*Methods@#Cluster random sampling method was used to selected 823 students from 2 schools of Xiamen in May, 2018, participants were asked to report individual masculine and feminine traits through the Child s Sex Role Inventory, and then gender role was divided into four types (masculine, feminine, androgynous, undifferentiated). Non parametric tests, generalized linear model, and Logistic regression model were used to explore the association between masculine and feminine traits, gender role and family factors.@*Results@#Compared with the boys from the nuclear family, the masculine traits were lower in boys of other families by 0.282( 95% CI = -0.452 --0.110), and the feminine traits were also lower by 0.192 (95% CI =-0.369--0.014). Compared with boys of middle socioeconomic status (SES), the masculine traits of boys from low SES decreased by 0.157 (95% CI =-0.286--0.029), and the feminine traits decreased by 0.140 (95% CI =-0.274--0.005). The proportion of androgynous in boys from other families was significantly lower than boys from the nuclear family ( OR =0.45, 95% CI =0.21-0.94), with the proportion of undifferentiated significantly higher than nuclear family 2.33 (95% CI =1.22-4.44). The proportion of androgynous in boys from low SES was significantly lower than boys from middle SES ( OR =0.59, 95% CI =0.35-0.99), with the proportion of undifferentiated significantly higher than middle SES 1.62 (95% CI =1.00-2.65). Among girls, the differences in masculine and feminine traits and gender role of different family factors were not statistically significant ( P >0.05).@*Conclusion@#The masculine and feminine traits and gender role in students are associated with family structures and socioeconomic status, especially in boys. Therefore, the family environment is an important factor affecting children s gender role, and the healthy development of children s gender role needs parents attention and correct guidance.
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Objective@#To analyze the association between sleep duration and social anxiety in Chinese children and adolescents to provide evidence for promoting healthy lifestyle and mental health in children and adolescents.@*Methods@#A total of 1 145 children and adolescents aged 7-16 were recruited by cluster random sampling in Beijing in 2020, and received a series of body measurements and questionnaire survey. Social Anxiety Scale for Children (SASC) and Pittsburgh Sleep Quality Index (PSQI) were used to evaluate the social anxiety symptoms and sleep duration of children and adolescents. T test was used to compare the differences of social anxiety level in different groups, and multivariate linear regression analysis was used to analyze the relationship between sleep duration and social anxiety.@*Results@#The average score of social anxiety was (5.47±4.18). The social anxiety score of girls, participants aged 13-16, with insufficient physical activity and insufficient sleep duration were higher ( t =-4.34, -6.14, 3.35, 2.93, P < 0.05). The results of multivariate linear regression model showed that after adjusting confounding factors, social anxiety decreased by 0.78 for each additional hour of sleep duration ( β =-0.78, 95% CI =-1.03--0.54, P <0.01), with 0.60 in boys (95% CI = -0.95 --0.25), 0.90 in girls (95% CI =-1.24--0.56), 0.75 among participants aged 7-12 (95% CI =-1.11--0.40) and 0.76 among participants aged 13~16 (95% CI =-1.11--0.41)( P <0.01), respectively. Social anxiety among participants who were not over weight or obese decreased by 0.78(95% CI =-1.09--0.48) and 0.81 among overweight and obese group (95% CI =-1.22- -0.41 )( P <0.01) for each additional hour of sleep duration, respectively.@*Conclusion@#Substantial differences in social anxiety are observed in children and adolescents by gender, age group and nutritional status. Sufficient sleep duration is significantly related to the decrease of social anxiety, and improve the overall level of student mental health.
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Objective@#To analyze the association between sleep duration and social anxiety in Chinese children and adolescents to provide evidence for promoting healthy lifestyle and mental health in children and adolescents.@*Methods@#A total of 1 145 children and adolescents aged 7-16 were recruited by cluster random sampling in Beijing in 2020, and received a series of body measurements and questionnaire survey. Social Anxiety Scale for Children (SASC) and Pittsburgh Sleep Quality Index (PSQI) were used to evaluate the social anxiety symptoms and sleep duration of children and adolescents. T test was used to compare the differences of social anxiety level in different groups, and multivariate linear regression analysis was used to analyze the relationship between sleep duration and social anxiety.@*Results@#The average score of social anxiety was (5.47±4.18). The social anxiety score of girls, participants aged 13-16, with insufficient physical activity and insufficient sleep duration were higher ( t =-4.34, -6.14, 3.35, 2.93, P < 0.05). The results of multivariate linear regression model showed that after adjusting confounding factors, social anxiety decreased by 0.78 for each additional hour of sleep duration ( β =-0.78, 95% CI =-1.03--0.54, P <0.01), with 0.60 in boys (95% CI = -0.95 --0.25), 0.90 in girls (95% CI =-1.24--0.56), 0.75 among participants aged 7-12 (95% CI =-1.11--0.40) and 0.76 among participants aged 13~16 (95% CI =-1.11--0.41)( P <0.01), respectively. Social anxiety among participants who were not over weight or obese decreased by 0.78(95% CI =-1.09--0.48) and 0.81 among overweight and obese group (95% CI =-1.22- -0.41 )( P <0.01) for each additional hour of sleep duration, respectively.@*Conclusion@#Substantial differences in social anxiety are observed in children and adolescents by gender, age group and nutritional status. Sufficient sleep duration is significantly related to the decrease of social anxiety, and improve the overall level of student mental health.
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Objective@#To analyze the trend of percentile changes in body composition among children and adolescents aged 7 to 18 by gender and age, and to provide a scientific basis for reference value.@*Methods@#A stratified cluster random sampling method was used to select 1 585 children and adolescents from September to December 2020. Use the GAMLSS to estimate the P 25 , P 50 and P 75 percentile value of gender, age specific body fat percentage (BF%), fat mass index (FMI) and fat free mass (FFM).@*Results@#In different age groups, body fat percentage of boys with normal nutritional status peaked at around 10-year old, among them, body fat percentage of 10-year old P 25 , P 50 and P 75 were 22.2%, 26.1% and 30.1%, respectively. Body fat percentage of obese boys was at a high level. Among girls, body fat percentage under different nutritional status did not change. With the increase of age, fat mass index plateaued slightly in normal and overweight boys. However, in obese boys, with the increase of age, FMI gradually increased with the increase of percentile, while the value of FMI gradually decreased in girls. Whether in boys or girls, with the increase of age, fat free mass index shows an increasing trend, and boys increase faster.@*Conclusion@#Under different nutritional status, there are differences in the percentile value of body fat percentage, fat mass index and fat free mass by gender and age, which can provide a scientific basis for reference value of body composition in children and adolescents.
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Objective@#To explore the association between growth patterns and blood pressure in children and adolescents with different nutritional status.@*Methods@#A total of 38 839 children and adolescents aged 6 to 8 years old were included in this study by stratified cluster sampling. The American Academy of Pediatrics 2017 Guideline was used to evaluate the blood pressure, the US 2000 CDC standard was used to determine different growth patterns, and the WHO Child and Adolescent Growth and Development Standard issued in 2007 was used to evaluate nutritional status. Variance analyses were used to compare the levels of systolic and diastolic blood pressure and growth patterns by nutritional status, and χ 2 test was used to compare the difference of prevalence. Multivariate Logistic regression model was used to analyze the association between growth patterns and blood pressure.@*Results@#The proportion of normal growth, catch up growth and catch down growth was 33.2%, 41.6% and 25.2%, respectively. Under different growth patterns, systolic blood pressure (105.17±12.33) mm Hg and diastolic blood pressure (66.55±8.75) mm Hg of catch up growth were higher than those of normal growth and catch down growth. In overweight and obesity, the prevalence of hypertension (24.9%), high systolic blood pressure (18.9%) and high diastolic blood pressure (15.0%) in catch up growth were higher than those in normal growth and catch down growth ( P <0.05). The risk of catch up growth to hypertension was higher in overweight and obesity ( OR =1.18, 95% CI =1.06-1.31) than in normal children and adolescents ( OR =1.15, 95% CI =1.05-1.27).@*Conclusion@#In catch up growth children and adolescents, hypertension and high blood pressure are higher than normal growth and catch down growth. Overweight and obesity than normal children and adolescents have a higher risk of hypertension.
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Objective@#To evaluate the association of short-term fine particulate matters (PM2.5) exposure and blood pressure in children and adolescents.@*Methods@#A total of 144 813 junior and senior middle school students who participated in the physical examination in the 2017-2018 academic year in a northern city of China, with complete record of demographic characteristics, blood pressure and no history of heart and other important organ diseases were selected as the study subjects. Data on PM2.5 and other pollutants and meteorological data were obtained from the nearest air quality and meteorological monitoring stations of each schools. A generalized linear mixed effect model was used to analyze the association between short-term exposure of PM2.5 and blood pressure.@*Results@#The 6 day average concentration of PM2.5 (lag05) increased by 10 μg/m 3 was associated with an increase of 0.177(95%CI=0.148-0.207)mm Hg (1 mm Hg=0.133 kPa) in systolic blood pressure and 4.4%(OR=1.044, 95%CI=1.030-1.058) increase of the prevalence of high systolic blood pressure. And it was also associated with -0.021(95%CI=-0.040--0.002)mm Hg decrease in diastolic blood pressure, but had no significant correlation with the prevalence of high diastolic blood pressure. In general, a 10 μg/m 3 increase of PM2.5 was associated with 3.3% increase in the prevalence of high blood pressure (OR=1.03, 95%CI=1.02-1.05), and difference of boys and girls were found in different lagged days (P<0.05).@*Conclusion@#Short-term exposure of PM2.5 is associated with increased systolic blood pressure and prevalence of high blood pressure among children and adolescents. Attention should be paid to the prevention of short-term exposure of PM2.5 to protect the health of children and adolescents.
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Objective@#To analyze the cumulative effect of preadolescent lifestyles on the prevalence and incidence of elevated blood pressure (EBP) in children, and to provide evidence for early hypertensive intervention.@*Methods@#In 2017, a cohort study on pubertal development was conducted in Xiamen, Fujian Province. Participants underwent a physical examination and questionnaire survey. Between 2017 and 2019, this study carried out a 2-year follow-up of 1 316 students whose complete data were obtained. Preadolescent lifestyles were assessed by referring to baseline survey results obtained in 2017, and the prevalence and incidence of EBP were determined according to blood pressure levels that were determined in 2019. The logistic regression model was used to analyze the influence of healthy lifestyles on the prevalence and incidence of EBP after adjusted for confounding factors.@*Results@#The prevalence of EBP in 2017 and 2019 was 25.0% and 23.3%, respectively, and its incidence was 18.9% after the 2-year follow-up. Children with a healthy lifestyle had a lower prevalence and incidence of EBP. The regression analysis showed that children who have more healthy lifestyle factors were at a lower risk of EBP (P<0.05). Compared with students with 0-2 healthy lifestyle factors, the OR value of EBP prevalence was 0.52 (95% CI=0.30-0.90) and the RR value of EBP incidence was 0.60(95%CI=0.29-1.22) in children with 4-5 healthy lifestyle factors. Among them, children who were overweight or obese were at a significantly lower risk of EBP prevalence (OR=0.29, 95%CI=0.10-0.81).@*Conclusion@#Preadolescent lifestyles seemed to have a cumulative effect on the occurrence of EBP. Maintaining a healthy lifestyle had a positive effect on reducing the risk of EBP, particularly in overweight and obese children, and this was due to their adoption of a comprehensive healthy lifestyle.
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Objective@#To explore the relationship between one-child and low height level classification among children and adolescents, and the effects of fruits, vegetables and physical activities on this association, and to provide as cientific reference for probing into and improving the differences of their height level between one child and child with siblings.@*Methods@#Using stratified cluster sampling method, 93 primary and secondary schools in 7 provinces and cities in China were selected for physical examination and questionnaire surveys. A total of 40 978 primary and middle school students aged 7-17 were selected. A multilevel Logistic regression model was used to analyze.@*Results@#Univariate analysis found that being one-child was less likely to be classified as low height level(OR=0.63, 95%CI=0.58-0.67); the multilevel model also found that the probability that one-child being at low height level was still lower(OR=0.78, 95%CI=0.73-0.85), and daily vigorous-intensity physical activities ≥1 h (OR=0.92, 95%CI=0.85-0.99) and daily vegetables and fruits intake ≥5 servings (OR=0.83, 95%CI=0.75-0.92) could also reduce the probability of being at low height level. Hierarchical analysis found that when vegetables and fruits intake and physical activities time were sufficient, there was no longer a significant difference in the height level classification between one-child and child with siblings(P>0.05).@*Conclusion@#Being one-child could be a protective factor for the height level classification of children and adolescents. Adequate intake of vegetables and fruits and time of vigorous-intensity physical activities could fill the gap of height level classification between of being one-child and child with siblings. Effective behavioral intervention measures should be taken to protect the healthy growth of height among children and adolescences.
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Objective@#To investigate the relationship between neglect , physical abuse and non-suicidal self-injury (NSSI) behaviors among middle school students in rural China.@*Methods@#A total of 14 162 adolescents in Anhui, Guangdong, Yunnan, Heilongjiang and Hubei provinces were selected by multi-stage cluster random sampling method. Data were obtained on demographic information, neglect, physical abuse and non-suicidal self-injury from questionnaire survey.@*Results@#During the past year before survey, 13.5% of participants engaged in self-injury 5 times or more, 15.4% of participants engaged in self-injury 1 to 4 times. Both neglect and physical abuse were significantly associated with self-injury in adolescents(P<0.01). After adjusted for gender, ethnicity, the only-one child, family structure, family economic status, and other variables, multinomial logistic regression showed that neglect and physical abuse were positively associated with self-injury behavior(OR=1.43-3.23). There was a potential dose-response relationship of accumulating physical abuse types and self-injury, with more physical abuse types, the higher risk of self-injury behavior.@*Conclusion@#Neglect and physical abuse experience should be considered as a risk factor for NSSI among adolescents in rural China. Specific intervention targeting neglect and physical abuse should be strengthened to reduce the occurrence of NSSI.
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Objective@#To explore mediation of emotional regulation in the association between aggression behavior and non-suicide self-injury among rural middle school students.@*Methods@#A multi-stage stratified random cluster sample of 14 291 middle school students from 15 cities in five provinces of China (Anhui, Yunnan, Guangdong, Heilongjiang, Hubei). A structured questionnaire was used to assess non-suicide self-injury, emotional regulation and aggressive.@*Results@#During the past year, about 28.51% of participates reported self-injury, with 13.39% of them had 5 times or more. The five dimensions of aggressive behavior were positively correlated with non-suicide self-injury(P<0.01), emotional regulation was negatively correlated with non-suicide self-injury(P<0.01). The mediating effect of emotional regulation between aggression (physical aggression, verbal aggression, indirect aggression, anger and hostility) and non-suicide self-injury was found significant, the ratio of whose were 25.93%, 22.73%, 19.61%, 27.55% and 18.80%, respectively.@*Conclusion@#Emotional regulation plays a mediating role in adolescent self-injury and aggression, indicating self-injury and aggression could be prevented by enhancing emotional regulation among adolescents.
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Objective@#To explore the relationship between non-suicidal self-injury and Internet addictive behavior in adolescents.@*Methods@#A cross-sectional survey of 15 538 middle school students across 5 provinces in China. Participants reported self- injury behavior during the past year and the Internet addition behaviors were assessed through Young’s Internet Addiction Test(IAT).@*Results@#The prevalence of self-reported 1-year NSSI, Internet addictive behavior and pre-addictive behaviors was 28.7%, 3.3% and 29.9%, respectively. After controlling for potential confounders, the Internet addition was positively correlated with NSSI, and the risk of all types of NSSI was higher in adolescent with Internet addition than those with mild suspected Internet addictive behavior(OR=1.3-2.8).@*Conclusion@#These findings indicate that Internet addition is associated with the incidence of NSSI in adolescents.
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@#Objective To explore the safety and feasibility of spontaneous breathing anesthesia combined with tubeless uniportal thoracoscopy in pulmonary bullae surgery. Methods Totally 112 patients with pulmonary bullae in the Affiliated Hospital of Inner Mongolia Medical University from March 2015 to May 2017 were enrolled. According to the random number chosen by computer, the patients were randomly divided into two groups: a tubeless group (spontaneous breathing anesthesia combined with tubeless uniportal thoracoscopy) and a control group (uniportal thoracoscopy by general anesthesia with tracheal intubation) . There were 49 males and 7 females with an average age of 25.5±6.5 years in the tubeless group, and 50 males and 6 females with an average age of 23.5±4.5 years in the control group. The difference of the lowest intraoperative arterial oxygen saturation (SaO2), SaO2 at postoperative one hour, operation time, postoperative awakening time, hospital stay, hospitalization cost and postoperative pain score were analyzed. Results There was no significant difference between the two groups in the operation time, the lowest SaO2, SaO2 at one hour after the operation and the partial pressure of carbon dioxide (PaCO2). The awakening time and duration of postoperative hospital stay in the tubeless group was shorter than those in the control group (P=0.000). The cost of hospitalization in the tubeless group was less than that in the control group (P=0.000). The discomfort caused by urinary tract and visual analogue score (VAS) in the tubeless group were better than those in the control group. Conclusion It is safe and feasible to use spontaneous breathing anesthesia combined with tubeless uniportal thoracoscopy in pulmonary bullae resection.
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Methemoglobin (Hb-M) is a rare hemoglobinopathy in China. We hereby report on a family living in Yantai, East China, with congenital cyanosis due to Hb-M mutation. The proband, a 65-year-old female, presented 63 percent oxygen saturation. Both Hb-M concentration and arterial oxygen saturation remained unchanged, even following intravenous treatment with methylene blue. There was also no change in blood-color (chocolate-brown) after adding 0.1 percent KCN. A fast-moving band (Hb-X) in hemolysates was found by cellulose acetate electrophoresis, the Hb-X/Hb-A ratio exceeding 10 percent. GT transition at 131nt of exon 2, although present in one of the alfa2-globin alleles, was not found in alfa1-globin alleles as a whole. This mutation leads to the aspartic acid to tyrosine substitution (Asp76Tyr). In this family, the novel mutation in the alfa2-globin gene resulted in a rare form of congenital cyanosis due to Hb-M. This hemoglobin was named Hb-M Yantai.
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Humans , Female , Aged , Cyanosis/congenital , Hemoglobin M , Methemoglobinemia/congenital , China , Globins , Methemoglobin/analysis , Polymerase Chain Reaction/methodsABSTRACT
The epidemic tendency of dental caries of school students over the past 15 years in China was analyzed in order to provide bases for prevention of dental caries.Data sets of boys and girls at the age of 7,9,12 years(deciduous caries)and 7,9,12,14,17 years(permanent caries)were collected from the series of Chinese National Surveillance on Students' Constitution and Health(CNSSCH)between 1991 to 2005,a survey that covers 30 provinces of and autonomous regions of China,with Tibet Autonomous Region and Taiwan Province excluded owing to unavailability of related data.According to their socioeconomic status,three urban regions and three rural regions(province capital must be included)were selected in each province,where its socioeconomic status and sports exercise can represent the general level of the locality.All subjects were Han students.Prevalence of deciduous and permanent caries was measured.In 2005,the prevalence of deciduous caries at 7,9,12 years was 52.87%,52.04% and 9.80% in urban boys,59.37%,58.68% and 12.18% in rural boys,and that of permanent caries in boys at 7,9,12,14,and 17 years was 2.35%,5.63%,13.94%,19.05% and 21.29% in urban boys,3.42%,7.26%,13.35%,16.16%,18.55% in rural boys,while in girls at the same age groups,the prevalence of deciduous caries was 53.53%,49.48%,7.92% in urban girls,59.95%,56.13%,8.85% in rural girls; the prevalence of permanent caries was 3.61%,8.99%,19.32%,24.75%,28.62% in urban girls,and 3.47%,10.65%,17.66%,22.52%,24.27% in rural girls.The epidemic manifested a gradient distribution in age groups,which was closely related to region of the study population.A dramatic decreasing trend was witnessed among all sex-age subgroups in the rural groups between 1990 and 2005,and such a trend was stronger in deciduous caries than in permanent caries,however,this kind of decreasing trend was not steady,because there was bounce during some year.Although the morbidity of dental caries in China is lower than the standard set by the World Health Organization,and the prevalence of dental caries decreased from 1991 to 2005,the prospect of epidemic dental caries in China is in no way optimistic.The total population with dental caries is still very large and the prevalence decreased unstably.Therefore,financial support on school oral health care should be increased,and a national school oral health service network should be set up.