Objective: To explore the sampling method in China National Human Biomonitoring Program (HBP) and the related errors, so as to calculate and evaluate the study design in sampling. Methods: The sampling method of HBP is of multistage nature. Taking the results of sampling method from Guizhou province as an example, results related to sampling error and variation coefficient were calculated, using the multistage unequal probability sampling error method. Results: The HBP covered 152 monitoring sites in 31 provinces (autonomous regions and municipalities) and with 21 888 residents selected. The replacement rates at various stages were 5.26%, 6.35% and 40.6% respectively. The sampling error in Guizhou province was 3 207 594, and the coefficient of variation was 0.097. Conclusions: According to the multi-stage unequal probability sampling method, the sampling coefficient variability appeared small with high precision, in Guizhou province. However, this method did not consider the weight adjustment of non-sampling errors such as population missing rate and response rate. Methods related to the calculation on multi-stage sampling error among large-scale public health monitoring projects need to be further studied.
China ; Cities ; Environmental Monitoring ; Humans ; Research Design

Objective: To analyze the spatial distribution of tuberculosis (TB) and identify the clustering areas in Qinghai province from 2014 to 2016, and provide evidence for the prevention and control of TB. Methods: The data of pulmonary TB cases confirmed by clinical and laboratory diagnosis in Qinghai during this period were collected from National Disease Reporting Information System. The visualization of annual reported incidence, three-dimensional trend analysis and local Getis-Ord G(i)(*) spatial autocorrelation analysis of TB were performed by using software ArcGIS 10.2.2, and global Moran's I spatial autocorrelation analysis were analyzed by using software OpenGeoDa 1.2.0 to describe and analyze the spatial distribution characteristics and high incidence areas of TB in Qinghai from 2014 to 2016. Results: A total of 20 609 pulmonary TB cases were reported in Qinghai during this period. The reported incidences were 101.16/100 000, 123.26/100 000 and 128.70/100 000 respectively, an increasing trend with year was observed (trend χ(2)=187.21, P<0.001). The three-dimensional trend analysis showed that the TB incidence increased from northern area to southern area, and up-arch trend from the east to the west. Global Moran's I spatial autocorrelation analysis showed that annual reported TB incidence in different areas had moderate spatial clustering (Moran's I values were 0.631 3, 0.605 4, and 0.587 3, P<0.001). And local G(i)(*) analysis showed that there were some areas with high TB incidences, such as 10 counties of Yushu and Guoluo prefectures (Gande, Banma and Dari counties, etc., located in the southwest of Qinghai), and some areas with low TB incidences, such as Huangzhong county, Chengdong district and Chengbei district of Xining city and Dachaidan county of Haixi prefecture, and the reported TB incidences in the remaining areas were moderate. Conclusion: The annual reported TB incidence increased year by year in Qinghai from 2014 to 2016. The distribution of TB cases showed obvious spatial clustering, and Yushu and Guoluo prefectures were the key areas in TB prevention and control. In addition, the spatial clustering analysis could provide the important evidence for the development of TB prevention and control measures in Qinghai.
China/epidemiology* ; Cluster Analysis ; Disease Notification/statistics & numerical data* ; Female ; Geographic Information Systems ; Humans ; Incidence ; Male ; Spatial Analysis ; Spatio-Temporal Analysis ; Tuberculosis/microbiology* ; Tuberculosis, Pulmonary/ethnology*

Heavy metal is one of pollutants existed widely in the environment, its relationship with cardiovascular disease has attracted more and more attention. In this review, the concentrations of heavy metals, including lead, cadium and asenic, in the body from several national surveillance networks and the epidemiological studies on the effects of the exposure of three heavy metals on cardiovascular system were summarized. It is suggested to strengthen nationwide surveillance for body concentrations of heavy metals in general population in order to provide baseline data for quantitative evaluation of the risk of heavy metal exposure on cardiovascular disease.
Cadmium ; Cardiovascular Diseases/chemically induced* ; Environmental Exposure/adverse effects* ; Environmental Pollutants/toxicity* ; Epidemiologic Studies ; Humans ; Lead/toxicity* ; Metals, Heavy/toxicity* ; Neoplasms ; Research/trends*

Objective: To understand the current status of smoking and smoking cessation in persons aged 15 years and over in Beijing and evaluate the effect of 2015 Beijing Tobacco Control Regulation. Methods: In 2014 and 2016, based on the principles and methodology of the Global Adult Tobacco Survey. A total of 50 communities or townships were selected from 324 communities or townships in Beijing through multistage cluster sampling, and 2 community (village) committees from each community or township were selected with the method of probability proportional to size (PPS). A total of 100 surveillance sites were set, and 100 households were selected from each surveillance site by using simple random sampling. Data were collected through face-to-face interview from the eligible family members aged 15 years and over with the assistance of a tablet computer. Statistical analyses were conducted by using complex sampling analyses module of SPSS 20.0, with weights as a combination of sampling weights, non-response weights and post- stratification weights, for the calculation of current smoking prevalence, daily smoking prevalence, smoking cessation rate, etc. Results: A total of 8 484 and 9 372 valid questionnaires were obtained, respectively, in 2014 and 2016, with the response rate of 86.5% and 96.5%. The current smoking prevalence in persons aged 15 years and over was 23.4% in 2014, and 22.3% in 2016. According to the 6(th) national census data, the current smoking population decreased by 199 000 in Beijing. The proportion of daily smokers declined from 20.7% in 2014 to 19.2% in 2016. The daily number of cigarettes consumed by current smokers increased from 14.6 in 2014 to 15.4 in 2016. The smoking cessation rate was 14.9% in 2014 and 16.8% in 2016. The proportion of current smokers who had at least one smoking cessation attempt in the past 12 months increased from 22.3% in 2014 to 23.2% in 2016, and the proportion of current smokers who planned to quit smoking increased from 11.6% to 15.5%. Among the current smokers who had visited doctors in the past 12 months, the proportion of those having smoking cessation advice was 58.9% in 2014 and 59.2% in 2016. In 2016, among the current smokers who had attempted to quit in the past 12 months, 36.8% were aware of the smoking cessation clinics, and 29.5%were aware of the quitline. Among those who were aware, only 7.7% had actually visited the cessation clinics, and 5.5% had used the quitline. Conclusions: After the implementation of 2015 Beijing Tobacco Control Regulation for 1 year, the current smoking prevalence in persons aged 15 years and over showed decreasing. It is necessary to further prompt the expansion of smoking cessation service to cover more current smokers.
Adolescent ; Adult ; Beijing ; Humans ; Middle Aged ; Smoking Cessation ; Social Control, Formal ; Nicotiana ; Tobacco Products/legislation & jurisprudence* ; Tobacco Use ; Young Adult

Objective: To analyze the characteristics of super-antigen (SAg) of group A Streptococcus pyogenes (GAS), isolated from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. Methods: Throat swab specimens from patients with scarlet fever or pharyngeal infections were collected and tested for GAS. Eleven currently known SAg genes including SpeA, speC, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa were tested by real-time PCR while M protein genes (emm genes) were amplified and sequenced by PCR. Results: A total of 377 GAS were isolated from 6 801 throat swab specimens, with the positive rate as 5.5%. There were obvious changes noticed among speC, speG, speH and speK in three years. A total of 45 SAg genes profiles were observed, according to the SAgs inclusion. There were significant differences appeared in the frequencies among two of the highest SAg genes profiles between emm1 and emm12 strains (χ(2)=38.196, P<0.001; χ(2)=72.310, P<0.001). There also appeared significant differences in the frequencies of speA, speH, speI and speJ between emm1 and emm12 strains (χ(2)=146.154, P<0.001; χ(2)=52.31, P<0.001; χ(2)=58.43, P<0.001; χ(2)=144.70, P<0.001). Conclusions: Obvious changes were noticed among SAg genes including speC, speG, speH and speK from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. SAg genes including speA, speH, speI and speJ appeared to be associated with the emm 1 and emm 12 strains. More kinds of SAg genes profiles were isolated form GAS but with no significant differences seen in the main SAg genes profiles, during the epidemic period.
Antigens, Bacterial/genetics* ; Bacterial Outer Membrane Proteins ; Bacterial Proteins ; Beijing/epidemiology* ; China/epidemiology* ; Exotoxins ; Female ; Humans ; Membrane Proteins ; Pharyngitis/microbiology* ; Pharynx/microbiology* ; Pregnancy ; Pregnancy Complications, Infectious/microbiology* ; Real-Time Polymerase Chain Reaction ; Scarlet Fever/microbiology* ; Streptococcal Infections ; Streptococcus pyogenes/isolation & purification* ; Superantigens/genetics*

Objective: To evaluate the frailty status and understand the relationship between the incidence of fall and frailty status in the elderly in Beijing. Methods: A cross-sectional study was conducted in old people aged ≥60 years in Longtan community of Dongcheng district in Beijing from November 2015 to January 2016. The information about any fall during the past year and frailty status of the elderly were collected with a standardized structured questionnaire in face-to-face interviews. The frailty status of elderly people was assessed with frailty index (FI) method. Logistic regression analysis was used to explore the relationship between fall and frailty status among the elderly. Results: Among 1 557 old people surveyed, the incidence of fall was 17.8% (277/1 557) during the past year. The incidence of fall in women (21.0%, 192/277) was statistically higher than that in men (13.3%, 85/277) (χ(2)=15.288, P=0.000). The median (quartile) value of FI of the elderly surveyed was 0.09 (0.08); and women had a higher FI median value than men [0.10 (0.08) versus 0.08 (0.07)](Z=5.376, P=0.000). The median FI value (quartile range) of 277 old people with history of fall in previous year was 0.12 (0.11), which was higher than the median FI value of 0.08 (0.07) of 1 280 old people without fall history (Z=7.501, P=0.000). Logistic regression analysis showed that higher FI value was associated with more risks for fall; and FI value showed the greatest impact on the incidence and frequency of fall (OR=1.093, 2.234) compared with other related factors of fall, such as age and gender. Conclusion: Frailty status has a greater impact on both incidence and frequency of fall compared with other factors in elderly people in Beijing; more attention should be paid to weak and old adults in the prevention of fall.
Accidental Falls/statistics & numerical data* ; Adult ; Aged ; Beijing ; Cross-Sectional Studies ; Female ; Frail Elderly ; Frailty ; Geriatric Assessment ; Humans ; Incidence ; Male ; Urban Population

Objective: To understand the epidemiological characteristics of scrub typhus and influencing factors in Yunnan province, and provide further information for the prevention and control of scrub typhus. Methods: Based on the incidence data of scrub typhus reported in Yunnan from 2006 to 2013, the epidemiological characteristics of scrub typhus were analyzed and related environmental factors were identified with panel negative binomial regression model. Results: A total of 8 980 scrub typhus cases were reported during 2006-2013 in Yunnan. The average annual incidence was 2.46/100 000, with an uptrend observed. Natural focus expansion was found, affecting 71.3% of the counties in 2013. The epidemic mainly occurred in summer and autumn with the incidence peak during July-October. The annual incidence was higher in females than in males. More cases occurred in children and farmers, the proportions of cases in farmers and pre-school aged children showed an obvious increase. Panel negative binomial regression model indicated that the transmission risk of scrub typhus was positive associated with monthly temperature and monthly relative humidity. Furthermore, an "U" pattern between the risk and the increased coverage of cropland and grassland as well as an "inverted-U" pattern between the risk and increased coverage of shrub were observed. Conclusion: It is necessary to strengthen the scrub typhus surveillance in warm and moist areas as well as the areas with high coverage of cropland and grassland in Yunnan, and the health education in children and farmers who are at high risk.
Child ; China/epidemiology* ; Environment ; Epidemics ; Farmers ; Female ; Humans ; Incidence ; Male ; Models, Statistical ; Orientia tsutsugamushi ; Risk Factors ; Scrub Typhus/transmission* ; Temperature

Objective: To explore the relationship between environmental factors as urinary cadmium and type 2 diabetes mellitus (DM) in adults. Methods: Case-control study was adopted, including 166 cases and 427 controls. General characteristics of the subjects were collected by a structured questionnaire. FPG, biochemical indexes and urinary cadmium (UCd) were detected respectively, while UCd was corrected with creatinine. Unconditioned logistic regression model was applied to analyze the relationship between UCd and DM. Results: Levels of UCd appeared higher in cases with the following characteristics as: having primary school education (P=0.016), being female (P=0.013), being non-smokers (P=0.014) or non-alcoholic (P=0.025), and with BMI>25.00 kg/m(2) (P=0.040, P=0.025) than those appeared in the control group. Same results were shown in the 60-69 years (P=0.024) old group. Data from the unconditional logistic regression analysis showed that family history of DM (OR=3.19, 95%CI: 1.45-7.03), education status (OR=1.50,95%CI: 1.08-2.08) and UCd (OR=1.61, 95%CI: 1.08-2.41) were influencing factors on DM. Conclusion: A close association between UCd and DM was noticed. UCd appeared a risk factor on DM that called for setting up related prevention program to reduce the exposure of Cd and to control the risk on DM.
Adult ; Cadmium/urine* ; Case-Control Studies ; China/epidemiology* ; Creatinine ; Diabetes Mellitus, Type 2/epidemiology* ; Female ; Humans ; Risk Factors ; Socioeconomic Factors

OBJECTIVES: To establish multiplex system of 16 miniSTR loci, and explore its application value for the degraded materials in forensic medicine. METHODS: The multiplex system of 16 miniSTR loci was established using a six-dye fluorescence labeling technology and its application value in forensic medicine was assessed. RESULTS: A six-dye fluorescence labeling miniSTR amplification kit was developed, which enabled 15 autosomal STR loci, Amelogenin locus and DYS391 to be typed simultaneously. This method showed good specificity and could provide stable and accurate typing results with a sensitivity of 50 pg. This system also provided a good test result for the normal biological sample of actual cases. CONCLUSIONS The multiplex system of 16 miniSTR loci has application value for degraded and trace materials with the advantages of high sensitivity and database compatibility, which can be used for forensic casework.
Amelogenin ; DNA Fingerprinting ; DNA Primers ; Forensic Medicine/methods* ; Microsatellite Repeats/genetics* ; Polymerase Chain Reaction

Objective: To identify related factors associated with unprotected anal intercourse (UAI) among HIV-positive men who have sex with men (MSM) in the context of knowing their HIV infection status. Methods: HIV positive MSM who known that they had been infected with HIV for more than 6 months and accepted follow up services were recruited by convenience sampling method in Chengdu 2015. Semi-structured questionnaire was used to collect their information, such as demographic characteristics, antiviral therapy and sexual behavior characteristics etc. Logistic regression model was used for univariate and multivariate analyses. Results: A total of 330 HIV- positive MSM were recruited, 201 eligible MSM were interviewed. The prevalence of UAI in recent six months was 18.41% (37/201). The results of multivariate logistic regression analysis revealed that the number of anal intercourse with male ≥3 in last month (OR=6.22, 95%CI: 1.88-20.56), low education level (OR=7.29, 95%CI: 1.36-39.16), married, divorced or widowed status (OR=4.65, 95%CI: 1.13-19.17), homosexual cohabitation (OR=3.32, 95%CI: 1.01-10.95) were the risk factors related with UAI among the HIV-positive MSM. Conclusion: Frequent homosexual anal intercourse, low education level, married, divorced or widowed status and homosexual cohabitation might be the risk factors related with UAI in HIV-positive MSM in Chengdu.
HIV ; HIV Infections/transmission* ; Homosexuality, Male ; Humans ; Male ; Risk-Taking ; Sexual Behavior ; Sexual Partners ; Sexual and Gender Minorities ; Unsafe Sex