Application of Next Generation Sequencing in Laboratory Medicine

The rapid development of next-generation sequencing (NGS) technology, including advances in sequencing chemistry, sequencing technologies, bioinformatics, and data interpretation, has facilitated its wide clinical application in precision medicine. This review describes current sequencing technologies, including short- and long-read sequencing technologies, and highlights the clinical application of NGS in inherited diseases, oncology, and infectious diseases. We review NGS approaches and clinical diagnosis for constitutional disorders; summarize the application of U.S. Food and Drug Administration-approved NGS panels, cancer biomarkers, minimal residual disease, and liquid biopsy in clinical oncology; and consider epidemiological surveillance, identification of pathogens, and the importance of host microbiome in infectious diseases. Finally, we discuss the challenges and future perspectives of clinical NGS tests.

Data science in large cohort studies / 中华流行病学杂志

Large cohort study gained its popularity in biomedical research and demonstrated its application in exploring disease etiology and pathogenesis, improving the prognosis of disease, as well as reducing the burden of diseases. Data science is an interdisciplinary field that uses scientific methods from computer science and statistics to extract insights or knowledge from data in a specific domain. The results from the combination of the two would provide new evidence for developing the strategies and measures on disease prevention and control. This review included a brief introduction of data science, descriptions on characteristics of large cohort data according to the development of the study design, and application of data science at each stage of a large cohort study, as well as prospected the application of data science in the future large cohort studies.

Interpretation for the group standards in data management for large population-based cohorts / 中华流行病学杂志

Precision medicine became the key strategy in development priority of science and technology in China. The large population-based cohorts become valuable resources in preventing and treating major diseases in the population, which can contribute scientific evidence for personalized treatment and precise prevention. The fundamental question of the achievements above, therefore, is how to construct a large population-based cohort in a standardized way. The Chinese Preventive Medicine Association co-ordinated experienced researchers from Peking University and other well-known institutes to write up two group standards Technical specification of data processing for large population-based cohort study (T/CPMA 001-2018) and Technical specification of data security for large population-based cohort study (T/CPMA 002-2018), on data management. The standards are drafted with principles of emphasizing their scientific, normative, feasible, and generalizable nature. In these two standards, the key principles are proposed, and technical specifications are recommended in data standardization, cleansing, quality control, data integration, data privacy protection, and database security and stability management in large cohort studies. The standards aim to guide the large population-based cohorts that have been or intended to be established in China, including national cohorts, regional population cohorts, and special population cohorts, hence, to improve domestic scientific research level and the international influence, and to support decision-making and practice of disease prevention and control.

Study on genetic structure differences and adjustment strategies in different areas of China / 中华流行病学杂志

Objective: To describe the genetic structure of populations in different areas of China, and explore the effects of different strategies to control the confounding factors of the genetic structure in cohort studies. Methods: By using the genome-wide association study (GWAS) on data of 4 500 samples from 10 areas of the China Kadoorie Biobank (CKB), we performed principal components analysis to extract the first and second principal components of the samples for the component two-dimensional diagram generation, and then compared them with the source of sample area to analyze the characteristics of genetic structure of the samples from different areas of China. Based on the CKB cohort data, a simulation data set with cluster sample characteristics such as genetic structure differences and extensive kinship was generated; and the effects of different analysis strategies including traditional analysis scheme and mixed linear model on the inflation factor (λ) were evaluated. Results: There were significant genetic structure differences in different areas of China. Distribution of the principal components of the population genetic structure was basically consistent with the geographical distribution of the project area. The first principal component corresponds to the latitude of different areas, and the second principal component corresponds to the longitude of different areas. The generated simulation data showed high false positive rate (λ=1.16), even if the principal components of the genetic structure was adjusted or the area specific subgroup analysis was performed, λ could not be effectively controlled (λ>1.05); while, by using a mixed linear model adjusting for the kinship matrix, λ was effectively controlled regardless of whether the genetic structure principal component was further adjusted (λ=0.99). Conclusions: There were large differences in genetic structure among populations in different areas of China. In molecular epidemiology studies, bias caused by population genetic structure needs to be carefully treated. For large cohort data with complex genetic structure and extensive kinship, it is necessary to use a mixed linear model for association analysis.

Relationship between educational level and long-term changes of body weight and waist circumference in adults in China / 中华流行病学杂志

Objective: To evaluate the association of educational level with anthropometric measurements at different adult stages and their long-term changes in adults who participated in the second re-survey of China Kadoorie Biobank (CKB). Methods: The present study excluded participants who were aged >65 years, with incomplete or extreme measurement values, or with major chronic diseases at baseline survey or re-survey. The weight at age 25 years was self-reported. Body height, body weight and waist circumference at baseline survey (2004-2008) and re-survey (2013-2014) were analyzed. Results: The present study included 3 427 men and 6 320 women. Both body weight and waist circumference (WC) increased with age. From age 25 years to baseline survey (mean age 45.2±6.5), the mean weight change per 5-year was (1.70±2.63) kg for men and (1.27±2.10) kg for women. From baseline survey to re-survey (53.2±6.5), the mean changes per 5-year for body weight were (1.12±2.61) kg for men and (0.90±2.54) kg for women; and that for WC was (3.20±3.79) cm for men and (3.83±3.85) cm for women. Among women, low educational level was consistently associated with higher body mass index (BMI) and WC at age 25 years, baseline survey and re-survey. Among men, low educational level was associated with higher BMI at age 25 years. At baseline survey and re-survey, the educational level in men was not statistically associated with BMI; but men who completed junior or senior high school showed slight higher WC and increase of WC from baseline survey to re-survey than other male participants. Conclusions: Body weight and WC increased with age for both men and women. The associations of educational level with BMI and WC were different between men and women.

Prevalence of 'healthy lifestyle' in Chinese adults / 中华流行病学杂志

Objective: To examine the prevalence of 'healthy lifestyle' from data extracted from the China Kadoorie Biobank (CKB) of 0.5 million adults from ten areas across China. Methods: After excluding participants with self-reported histories of coronary heart disease, stroke or cancer, a total of 487 198 participants at baseline (2004-2008) and 22 604 participants at second survey (2013- 2014), were included for analysis. 'Healthy lifestyle' was defined as haing the following characteristics: a) never smoking or having stopped smoking for reasons other than illness; b) alcohol drinking <25 g/day (men)/<15 g/day (women); c) diet rich in vegetables, fruits, legumes and fish, but low in red meat; d) upper quarter of the physical activity level; e) body mass index of 18.5-23.9 kg/m(2) and waist circumstance <85 cm (men)/80 cm (women). We calculated the healthy lifestyle scores (HLS) by counting the number of all the healthy lifestyle factors, with a range from 0 to 6. Results: At baseline, prevalence rates of the above five healthy lifestyles (except physical activity) were 70.6%, 92.6%, 8.7%, 52.6% and 59.0%, respectively, with the mean HLS being 3.1±1.2. Most participants (81.4%) had2-4 healthy components, while only 0.7% (0.2% in men and 1.0% in women) of all the participants had all six healthy lifestyles. Participants who were women, at younger age, with more schooling and rural residents, were more likely to adhere to the healthy lifestyle. After ten years, the mean HLS showed a slight decrease. Conclusion: The prevalence of optimal lifestyles in Chinese adults appeared extremely low. Levels of 'healthy lifestyle' varied greatly among those populations with different socio-demographic characteristics across the ten areas in China.

Impact of menarche age on the near-term and long-term obesity of adult females / 中华流行病学杂志

Objective: To study the relationship between the age of menarche and the near-term/long-term obesity in adult women. Methods: We analyzed the baseline data of 30 895 women with complete data on menarche and body measurement that was from the China Kadoorie Biobank (CKB) study from 2004 to 2008. The age of menarche was divided into three groups: ≤12, 13-16 and ≥17 years old. Prematurity was set at age ≤12 years. Multivariate logistic regression was used to analyze the effects of menarche age on the near/long-term obesity in female adults. Results: The average menarche age of respondent appeared as (15.64±1.92) years old, with prematurity number as 1 421, accounting for 4.6% of the total numbers. Regarding the postponing of dates of birth, the age of menarche in women showed an advancing tendency. Among all the adult women under study, 803 developed near-term obesity, with the prevalence as 2.6%, while the number of long-term obesity was 3 738, accounting for 12.1%. Refining factors of age, lifestyle, menopausal status, hypertension and diabetes showed that the menarche age was related to the risks of both short-term and long-term obesity in women and the ORs (95%CI) were 2.45 (1.74-3.45) and 1.99 (1.69-2.34), respectively. There was no multiplicative interaction shown between the menarche age and menopausal status on long-term obesity (P=0.324). Conclusion: Premature menarche appeared a risk factor for near-term/long-term obesity in adult females.

Prevalence of antiretroviral drug resistance in treatment-naive injecting drug users infected with HIV-1 in Guangzhou, 2008-2015 / 中华流行病学杂志

Objective: To understand the prevalence of drug resistance in treatment-naive injecting drug users (IDUs) infected with HIV-1 in Guangzhou. Methods: HIV-1 RNA were extracted from the serum specimens of the newly confirmed HIV-1 positive IDUs living in Guangzhou, being infected through injecting drug use and receiving no antiretroviral therapy at the time of confirmation during 2008-2015. Full sequence of pol protease (PR) gene and partial sequence of reverse transcriptase (RT) gene were amplified by nested reverse transcription polymerase chain reaction (nested-PCR) and sequenced. After that, data were submitted to the HIV resistance database of Stanford University for drug resistance analysis. Results: Among the 518 HIV-1 infected IDUs, HIV-1pol gene segments were successfully obtained from the serum samples of 407 HIV-1 infected IDUs (78.57%) aged 18-64 (37.44±8.14) years. Among them, males accounted for 89.68% (365/407), those of Han ethnic group accounted for 89.93% (366/407), the unmarried accounted for 55.28% (225/407), and those with education level of junior high school or below accounted for 83.78% (341/407). The distribution of subtypes was predominated by CRF07_BC (47.18%, 192/407), followed by CRF01_AE (23.83%, 97/407), CRF08_BC (22.85%, 93/407), and other subtypes (6.14%, 25/407). The overall prevalence of drug resistance was 3.44% (14/407). The prevalence of drug resistance to protease inhibitors, nucleoside reverse transcriptase inhibitors and non-nucleoside reverse transcriptase inhibitors were 1.47%(6/407), 0.25% (1/407) and 1.72% (7/407) respectively. The mutation rate was 12.29% (50/407). No major drug resistance mutation was detected in protease and nucleoside reverse transcriptase regions. Higher rate of V179E mutation in the non-nucleoside reverse transcriptase region was detected in other subtypes and subtype CRF07_BC. Mutation seemed to have occurred in all 8 cases of subtype CRF55_01B in other subtypes. The highest mutation rate of E138A was detected in subtype CRF08_BC (3.23%). Two cases were resistant to all four drugs of NNRTIs. Conclusions: The prevalence of drug resistance in treatment-naive HIV-1 positive IDUs remained at a relatively low level during 2008-2015, in Guangzhou. Most infections were sensitive to existing antiviral drugs. However, drug resistance surveillance in IDUs infected with HIV should be strengthened to prevent the prevalence of multi-drug resistance and cross drug resistance.

Family history and risk of coronary heart disease / 中华流行病学杂志

Objective: To evaluate the association of family history with risk of major coronary events (MCE) and ischemic heart disease (IHD). Methods: After excluding participants with heart disease, stroke or cancer at baseline survey, a total of 485 784 participants from the China Kadoorie Biobank, who had no missing data on critical variables, were included in the analysis. Cox regression analysis was used to estimate the hazard ratios (HR) and 95% CI. Subgroup analyses were performed according to the baseline characteristics. Results: During a median of 7.2 years of follow-up, we documented 3 934 incident cases of MCE and 24 537 cases of IHD. In multivariable-adjusted models, family history was significantly associated with risk of MCE and IHD. The adjusted HRs (95%CI) were 1.41 (1.19-1.65) and 1.25 (1.18-1.33), respectively. History of disease among siblings was more strongly associated with early-onset MCE than parental history (HR=2.97, 95%CI: 1.80-4.88). Moreover, the association of family history with MCE and IHD was stronger in persons who were overweight or obesive, and the association between family history and MEC was stronger in smokers. Conclusion: This large-scale, prospective study indicated that family history was an independent risk factor for MCE and IHD in China. The intervention targeting major known lifestyle risk factors and the management of chronic diseases should be strengthened for Chinese population, especially for the individuals with family history were at high risk.

Study on prevalence of physical activity in rural residents in four counties (districts) of Shanxi and Chongqing / 中华流行病学杂志

Objective: To investigate the prevalence of physical activity and its influencing factors in rural residents in Shanxi and Chongqing. Methods: In four counties (districts) of Shanxi and Chongqing, local residents aged ≥18 who lived there for more than one year and had no plan to migrate to other areas in 2 years were surveyed through face to face questionnaire interviews to collect the information about their daily physical activity time, sedentary time, related knowledge and attitude, and others. Results: The physical inactivity rate of the residents was 14.9%, and 88.7% of residents never took daily physical activity. The average sedentary time was (3.91±2.06) hours. The results of multivariate analysis showed that education level, per capita monthly income and activity degree were the factors influencing physical inactivity. Conclusion: The proportion of people who never took daily physical activity in the survey area was higher than the average level in rural areas in China, so measures should be taken to improve the overall rate of physical activity. For people who have exercise willingness, but have no practice, and those who have already increased their physical activities, targeted guidance is needed on the basis of strengthened health education.

Prevalence of HIV infection and syphilis and related behaviors in clients in Ya'an of Sichuan province / 中华流行病学杂志

Objective: To understand the prevalence of HIV infection and syphilis in clients in Ya'an of Sichuan province. Methods: A survey was conducted in clients recruited through snowball method in Ya'an of Sichuan from April 2014 to December 2015. The information of the clients, including basic demography characteristics, AIDS knowledge awareness, high-risk behaviors and others, were collected through face-to-face interviews. Blood sample (5 ml) was taken from each client to test antibodies against HIV and syphilis. Statistical software SPSS 18.0 was used for data analysis. Results: Among the 708 clients, the constituent ratio of those aged ≥50 years was 51.27% (363/708), those in Han ethnic group was 99.72% (706/708), those with junior high school educational level or below was 90.11% (638/708), those who got married or cohabitated with others was 74.15% (525/708), and those who used condoms at each sex was 27.40% (194/708). Seven HIV positive cases were detected and 4 cases were aged ≥50 years. Seven syphilis cases were detected and all the cases were aged ≥50 year. No HIV-syphilis co-infection case was detected. The prevalence of HIV infection and syphilis were all 0.99% (95%CI: 0.30%-1.70%). Results from the multivariate logistic regression analysis showed that the clients who had their first commercial sex behavior at age <30 years (OR=6.61, 95%CI: 1.09-40.18) would have higher HIV positive rate. Conclusion: The rate of condom use was low in the clients in Ya'an and they didn't pay enough attention to their self-protection in sexual activities. Especially the clients aged ≥50 years were with low educational level and had high risk commercial sexual behaviors for HIV infection and syphilis. Close attention needs to be paid to them.

Implementing the strategy of 'Healthy China' and strengthening the setting-up of National Demonstration Areas, for Comprehensive Prevention and Control of Non-communicable Diseases / 中华流行病学杂志

The former Ministry of Health launched a project regarding National Demonstration Areas for Comprehensive Prevention and Control of Non-communicable Diseases (NCDs) in 2010. This study combined quantitative and qualitative methods, using epidemiological, anthropological and sociological methods to carry out process assessment, effectiveness and case study to evaluate the outcomes of the Demonstration Areas in China. A government leading body, under multi-sectoral cooperation pattern set for prevention and control of NCDs in the Demonstration Areas, was established. All the health related indicators of the residents from the NCDs appeared better than the national average level, showing the fact that the first phase goal on the establishment of Demonstration Areas was materialized. Papers that included in this issue "Evaluation on China National Demonstration Areas for NCDs Prevention and Control" elaborated the implementation status and effectiveness of the Demonstration Areas. It was our hope to provide reference for scaling up the Demonstration Areas and dynamic management in the future.

Levels of calcaneus bone mineral density in adults from 10 regions of China / 中华流行病学杂志

Objective: To describe the regional and population-related differences in calcaneus bone mineral density (BMD) across ten regions of China. Methods: Based on the results: from the second Re-survey of China Kadoorie Biobank project, in which 5% of the surviving participants were interviewed during 2013-2014 and 24 677 participants aged 38-87 years were included in the study. We excluded those people with missing data for BMD and important variables. Calcaneus BMD was measured using the quantitative ultrasound bone densitometer. We analyzed four indexes, including broadband ultrasound attenuation (BUA), speed of sound (SOS), stiffness index (SI), and T score. Results The average calcaneus BMDs of the present population were: BUA (109.7±12.6) dB/MHz, SOS (1 554.7±45.6) m/s, SI (88.3±18.8), T score (-0.74±1.28). Urban residents showed higher calcaneus BMD, so as in men. The calcaneus BMD decreased by age, with a larger decline seen in women. Current smokers and postmenopausal women presented lower calcaneus BMD, while in those who frequently drank milk or yogurt or being physically more active, had higher calcaneus BMD. Conclusion: Calcaneus BMD varied greatly among people from the ten regions of CKB study and among participants having different demographic characteristics, lifestyle behaviors or health conditions.

Association between obesity and DNA methylation among the 7-16 year-old twins / 中华流行病学杂志

Objective: On whole-genome scale, we tried to explore the correlation between obesity-related traits and DNA methylation sites, based on discordant monozygotic twin pairs. Methods: A total of 90 pairs of 6-17 year-old twins were recruited in Chaoyang district, Yanqing district and Fangshan district in Beijing in 2016. Information on twins was gathered through a self-designed questionnaire and results: from physical examination, including height, weight and waist circumference of the subjects under study. DNA methylation detection was chosen on the Illumina Human Methylation EPIC BeadChip. R 3.3.1 language was used to read the DNA methylation signal under quality control on samples and probes. Ebayes function of empirical Bayes paired moderated t-test was used to identify the differential methylated CpG sites (DMCs). VarFit function of empirical Bayes paired moderated Levene test was used to identify the differentially variables CpG sits (DVCs) in obese and normal groups. Results According to the obesity discordance criteria, we collected 23 pairs of twins (age range 7 to 16 years), including 12 male pairs. A total of 817 471 qualified CpG loci were included in the genome-wide correlation analysis. According to the significance level of FDR set as <0.05, no positive sites would meet this standard. When DMC CpG site cg05684382, with the smallest P value (1.26E-06) as on chromosome 12, the DVC CpG site cg26188191 with the smallest P value (6.44E-06) appeared in CMIP gene on chromosome 16. Conclusions: In this study, we analyzed the genome-wide DNA methylation and its correlation with obesity traits. After multiple testing corrections, no positive sites were found to have associated with obesity. However, results from the correlation analysis demonstrated sites cg05684382 (chr: 12) and cg26188191 (chr: 16) might have played a role in the development of obesity. This study provides a methodologic reference for the studies on discordance twins related problems.

Effect of family environment in childhood and adolescence on mental health in adulthood / 中华流行病学杂志

Objective: To explore the relationship of family environment in childhood and adolescence and mental health in adulthood. Methods: A total of 791 subjects aged ≥25 years were selected through the Chinese National Twin Registry (CNTR). The short-form of Family Environment Scale-Chinese Version (FES-CV) was used to evaluate the family environment during childhood and adolescence in three dimensions: relationship, system maintenance and personal growth. The mental health status in adulthood was assessed with the Chinese version of 6-item Kessler Psychological Distress Scale (K6). The generalized linear mixed model was used to examine their relationship. Results: About 4.6% of the subjects reported general or worse mental health status. Compared with the subjects with good mental status, statistical difference was observed only in parenting way among twins (living together or not). After adjusting the potential confounders, such as age, sex, zygosity, education and lifestyle (smoking, drinking and physical activity), good family relationship and system maintenance had a positive effect on mental health, with the OR (95%CI) of 0.66 (0.51-0.87) and 0.70 (0.50-0.98) respectively. Furthermore, parenting way did not modify the effect of family environment on mental health status in adulthood (interaction: P>0.05). In each scale, scores of cohesion and organization were positively correlated with mental health, while the score of conflict was negatively correlated with the mental health. Conclusion: Good family relationship and system maintenance in childhood and adolescence had a positive impact on mental health in adulthood.

Prevalence and distribution of hypertension in population aged 15 years and over in Guizhou province / 中华流行病学杂志

Objective: To understand the prevalence and distribution of hypertension in population aged 15 years and over in Guizhou province and provide evidence for the prevention and management of hypertension. Methods: Face to face interviews using national standard questionnaire were conducted among the study subjects selected in Guizhou through multi-stage random sampling. Blood pressure measurement for them was done with Omron HEM-1300 professional portable blood pressure monitor. SPSS 19.0 software was used for statistical analysis. The ratio was compared by the χ(2) test. The influencing factors of hypertension was analyzed by multivariate logistic regression analysis. Results: A total of 13 480 participants were investigated, including 5 509 (40.8%) men and 7 971 (59.2%) women; 6 558 (48.6%) urban residents and 6 922 (51.4%) rural residents. Among the subjects surveyed, 3 232 (23.9%) were smokers, 2 412 (17.9%) were alcoholic and 4 859 (36.0%) were obese or overweight. A total of 3 937 (29.2%) hypertension patients were found. The prevalence of hypertension was 29.2%. The standardized prevalence of hypertension were 18.97% (compared with national population composition) and 21.16% (compared with Guizhou province population composition), respectively. The hypertension prevalence in men and women were 29.8% and 28.8%, respectively. The hypertension prevalence in rural population (35.8%) was higher than that in urban population (22.2%). The difference was statistically significant (P<0.001). The hypertension prevalence in people aged 65 years and over was 56.2%. The prevalence of hypertension were 34.3% and 27.6% in smokers and non-smokers, 39.2% and 27.0% in alcoholic and non-alcoholic and 40.7% and 22.7% in obese or overweight group and normal or less weight group, respectively. There were significant statistical differences in prevalence of hypertension among the population in urban area and rural area, with different age, education levels, smoking status, drinking status and BMI (P<0.001). Conclusions: The prevalence of hypertension in Guizhou was at a high level. The hypertension prevalence in rural area was higher than that in urban area. Hypertension prevalence increased significantly with age. The prevalence of hypertension was negatively associated with the education level of the people. Older age, living in rural area, smoking, drinking, obesity were the risk factors for hypertension.

Systems epidemiology / 中华流行病学杂志

The era of medical big data, translational medicine and precision medicine brings new opportunities for the study of etiology of chronic complex diseases. How to implement evidence-based medicine, translational medicine and precision medicine are the challenges we are facing. Systems epidemiology, a new field of epidemiology, combines medical big data with system biology and examines the statistical model of disease risk, the future risk simulation and prediction using the data at molecular, cellular, population, social and ecological levels. Due to the diversity and complexity of big data sources, the development of study design and analytic methods of systems epidemiology face new challenges and opportunities. This paper summarizes the theoretical basis, concept, objectives, significances, research design and analytic methods of systems epidemiology and its application in the field of public health.

Study on the prevalence of HIV infection and related risk behaviors among male new-type drug users in Qingdao, Shandong province / 中华流行病学杂志

Objective: To understand the characteristics of new-type drug consumption, sexual behaviors and the prevalence of HIV infection among male new-type drug users in Qingdao, Shandong province. Methods: A cross sectional survey was conducted from 2015 to 2016. Participants were recruited from MSM community-based organizations (CBO) and general community through snowball method, relying on volunteers and male peer educators who were on new-type drugs themselves. Face-to-face interview was carried to collect information on drug use and sexual behaviors. Blood samples were collected to test HIV, syphilis and HCV antibodies. Urine samples were collected to test the evidence of new-type drugs. Qualitative variables and quantitative variables were analyzed using Chi-square test/Fisher's exact test and Student's t-test respectively. Multivariate logistic regression was used to analyze related factors of binary variables. Results: A total of 1 034 newtype drug users were recruited, including 431 (41.7%) MSM population and 603 (58.3%) who were not MSM. Compared with the the group of people who were not MSM, people in the the MSM group were younger, unmarried and with higher level of education. The proportion of methamphetamine users were 49.7% (214/431) and 100.0% (603/603) among the groups of MSM or not MSM, respectively. People in the MSM group, 66.8% (288/431) used 5-Methoxy-N, N-diisopropyltryptamine (5-MeODIPT, "foxy" ) in the last six months. However, none from the not-MSM group ever used 5-MeO-DIPT. In the last six months, proportions of sharing new-type drugs with more than two people in the MSM or not groups were 87.9% (379/431) and 97.7% (588/602), respectively (χ(2)=39.84, P<0.01). Proportions of unprotected sexual behavior among the MSM or not groups were 47.5% (285/600) and 7.4% (32/430) respectively (χ(2)=190.10, P<0.01). The proportions of 'group sex' after using drugs among the two groups were 78.1% (335/429) and 5.5% (33/600) respectively (χ(2)=573.73, P<0.01). The prevalence rates of HIV, syphilis and HCV antibody positive among the MSM or not groups were 2.1% and 0.2%, 3.3% and 6.3%, 0.0% and 0.3%, respectively. Conclusion: The prevalence of sharing new-type drugs with more than two people was high among male new-type drug users in Qingdao city. Male new-type-drug-users who were MSM, presented both high prevalence of group sex and HIV infection, and with less condom use. Intervention measures towards this sub-population should be strengthened.

Prospective study on the effect of BMI and waist circumference on diabetes of adults in Zhejiang province / 中华流行病学杂志

Objective: To explore the effect of BMI and waist circumference on diabetes of adults. Methods: After excluding participants with heart disease, stroke, cancer and diabetes at baseline study, 53 916 people aged 30-79 in the China Kadoorie Biobank (CKB) study from Tongxiang city of Zhejiang province were recruited. Cox regression model was used to estimate the hazards ratios (HR) for the associations of baseline BMI and waist circumference with incident diabetes. Results: Among 391 512 person-years of the follow-up program between 2004 and 2013 (median 7.26 years), a total of 944 men and 1 643 women were diagnosed as having diabetes. Compared to those with normal weight, after adjusting for known or potential factors, HR of both overweight and obesity in men for incident diabetes appeared as 2.72 (95%CI: 2.47-2.99) and 6.27 (95%CI: 5.33-7.36), respectively. The corresponding figures in women were 2.19 (95%CI: 2.04-2.36) and 3.78 (95%CI: 3.36-4.26). Compared to those with normal waist circumference, after adjusting for known or potential factors, HR of Ⅰgrade andⅡgrade in men for diabetes were 2.56 (95%CI: 2.22-2.95) and 4.66 (95%CI: 4.14-5.24), respectively. The corresponding figures in women were 1.99 (95%CI: 1.80-2.21) and 3.16 (95%CI: 2.90-3.44), respectively. Conclusions: Overweight, obesity and central obesity were all associated with the increased incident of diabetes. Strategies on diabetes prevention should include not only losing weight, but reducing waist circumference as well.

Spatial-temporal analysis on pulmonary tuberculosis in Beijing during 2005-2015 / 中华流行病学杂志

Objective: To analyze the spatial distribution and identify the high risk areas of pulmonary tuberculosis at the township level in Beijing during 2005-2015. Methods: Data on pulmonary tuberculosis cases was collected from the tuberculosis information management system. Global autocorrelation analysis, local indicators of spatial association and Kulldorff's Scan Statistics were applied to map the spatial distribution and detect the space-time clusters of the pulmonary tuberculosis cases during 2005-2015. Results: Spatial analysis on the incidence of pulmonary tuberculosis at the township level demonstrated that the spatial autocorrelation was positive during the study period. The values of Moran's I ranged from 0.224 3 to 0.291 8 with all the P values less than 0.05. Hotspots were primarily distributed in 8 towns/streets as follows: Junzhuang, Wangping, Yongding and Tanzhesi in Mentougou district, Yancun in Fangshan district, Wangzuo town in Fengtai district, Tianqiao street in Xicheng district and Tianzhu town in Shunyi district. Spatiotemporal clusters across the entire study period were identified by using Kulldorff's spatiotemporal scan statistic. The primary cluster was located in Chaoyang and Shunyi districts, including 17 towns/streets, as follows: Cuigezhuang, Maizidian, Dongfeng, Taiyanggong, Zuojiazhuang, Hepingjie, Xiaoguan, Xiangheyuan, Dongba, Jiangtai, Wangjing, Jinzhan, Jiuxianqiao, Laiguangying, Sunhe towns/streets in Chaoyang district, Houshayu and Tianzhu town in Shunyi district, during January to December 2005. Conclusion: Incidence rates of pulmonary tuberculosis displayed spatial and temporal clusterings at the township level in Beijing during 2005-2015, with high risk areas relatively concentrated in the central and southern parts of Beijing.