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.

Relationship between urinary cadmium and type 2 diabetes mellitus in adults / 中华流行病学杂志

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.

LC-MS analysis of sintilimab as an anti-PD-1 therapeutic mab for its improved hinge stability study / 药学学报

Monoclonal antibodies (mAbs) have been widely used as therapeutic drugs for treating diseases such as cancers and auto-immune diseases. When using an IgG4 isotype, one of the challenges is the instability of its hinge which is prone to Fab-arm exchange (FAE). The hinge sequence of a wild type IgG4 is -CPSC-, however, a single point mutation S228P from -CPSC- to -CPPC- can effectively diminish FAE, thereby improving hinge stability of the IgG4 molecule. Sintilimab is the fully human anti-PD-1 monoclonal antibody designed and developed for immuno-oncology, in which serine 228 in the hinge was engineered to proline to mitigate FAE. In this study, LC-MS is used to study hinge stability of sintilimab in both in vitro (PBS and human serum) and in vivo (SCID mouse) studies. The studies demonstrate that LC-MS is a fast and simple way to monitor for the occurrence of FAE in vitro and in vivo, and FAE can be eliminated by antibody engineering with a single point mutation.

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.

A cross-sectional study on the status of tobacco use among junior middle school students in Shaanxi province / 中华流行病学杂志

Objective: To understand the rate on tobacco use and associated factors in junior middle school students in Shaanxi province. Methods: We used a multi-stage stratified random sampling method to select students from 30 junior middle schools in 10 areas of Shaanxi province in 2013. All the participants completed a self-administered questionnaire. Results: A total of 4 633 questionnaires were dispatched and 4 298 were qualified for further analysis. The current smoking rate of junior middle school students in Shaanxi was 6.5%, with rate in male (11.1%) higher than that of female students (1.7%). The current smoking rate of students in grade three (9.3%) was higher than those of students in grade one (3.5%) or in grade two (7.0%). The smoking rate of students with pocket money more than 31 Yuan per week was (10.0%) higher than those of students with pocket money less than 10 Yuan (4.6%) or 10-30 Yuan (6.3%) per week. Results from the logistic regression analysis showed that factors as: male, school located in the city, older age, with more pocket money, having smokers in the family and exposure to second hand smoking were high risk factors for current smoking. Conclusion: Rate on current smoking was high in junior middle schools students in Shaanxi, suggesting that comprehensive intervention programs be developed to reduce the rate of tobacco use in junior middle school students.

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.

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.

General plan of Shanghai Diet and Health Survey / 中华流行病学杂志

Shanghai Diet and Health Survey (SDHS) was designed to prospectively access local residents' food consumption, energy and nutrient intake, related chemical contaminant exposure, and the seasonal change trend to explore the relationship of diet with health. Data from SDHS can be used as fundamental information and scientific evidences for the development of local nutrition and food safety policies.

Dietary pattern and its seasonal characteristic in residents of Shanghai, 2012-2014 / 中华流行病学杂志

Objective: To analyze dietary pattern and its seasonal characteristic in residents of Shanghai. Methods: A representative sample was surveyed and followed up in four different seasons during 2012-2014. Information of food consumption was collected by 3-day 24-hour dietary recall and condiments weighing method. The intake of energy and macronutrients were calculated according to the Chinese Food Composition Table. Results: Annual average daily intake was 191.09 g for grain, 250.69 g for vegetable, 107.23 g for fruit, 223.53 g for animal food, 96.39 g for dairy products, 11.19 g for soy bean and its product, 36.54 g for cooking oil, and 7.57 g for salt. Significant differences were observed in food consumption among different seasons (P<0.05). Annual average daily intake of energy was 2 048.70 kcal, carbohydrates was 241.04 g, protein was 82.35 g, fat was 85.99 g and proportion of energy contributed by fat was 37.99%. Different seasons, age, residential areas, and income were influence factors for food consumption (P<0.05). Conclusions: Energy intake was adequate in residents of Shanghai. Unhealthy dietary pattern, including high proportion of fat and consumption of cooking oil and salt (lower than average intake of large cities, but higher than recommendation), was observed. It is necessary to take appropriate nutrition intervention, and future researches on dietary intake should consider seasonal influences.

Dairy product intake and influencing factors in residents of Shanghai / 中华流行病学杂志

Objective: To understand the dairy product intake in residents of Shanghai, its seasonal changes and the influencing factors. Methods: A group of representative residents was surveyed and followed up in four seasons in Shanghai during 2012-2014. Information of the dairy product intake was collected by food frequency questionnaire. Results: Liquid milk and yogurt were the main dairy products consumed by the residents of Shanghai. The annual dairy product intake rate was 41.8%, and the median of dairy intake of milk was 145.3 g/d, accounting for 48.4% of reference dietary intake value, and only 4.5% of people's diary product intake reached intake reference value. The area specific differences in intake rate of liquid milk, yogurt and total dairy product intake were significant in four seasons and in whole year (P<0.05). The area specific differences in total dairy product intake were significant (P<0.05) in spring, summer and winter. In general, it was shown that dairy product intake in urban area was higher than that in suburban area and in rural area. The data of Shanghai and urban area showed that the total dairy product intake was significant different among four seasons (P<0.05), but no significant difference was observed among four seasons in suburban and rural areas. The logistic regression analysis results showed that people with average household income higher than local average level or higher education levels were more likely to consume dairy products daily. People who reported to have good health status or sleep quality were more likely to drink milk compared to those who have worse health status or sleep quality (P<0.05). Conclusions: Even though dairy product intake rate and volume have been improved in residents in Shanghai, it is still stay at lower level, especially in rural area. To promote consumption of dairy products, it is necessary to control diary product price from macro perspective, and strengthen healthy education about the importance of dairy product intake and guide residents to select suitable dairy products.

Source tracing of the Yersinia pestis strains isolated from Heqing county, Yunnan province in 2017 / 中华流行病学杂志

Objective: To understand the genotype of the Yersinia (Y.) pestis strains isolated from Heqing county, Yunnan province in 2017 and provide evidence for the prevention and control of plague in this area. Methods: Ten Y. pestis strains isolated from Heqing were typed by the detections of different region (DFR) and clustered regularly interspaced short palindromic repeats (CRISPRs) as well as multiple-locus variable-number tandem repeat analysis (MLVA). And the results were compared with those of the 93 Y. pestis strains from the adjacent plague foci of Heqing obtained from the established database for clustering analysis. Results: The results showed that Heqing strains had the same type of DFR (Genomovar 05) and CRISPRs (Cluster Ca7, Type 22) with isolates from the plague focus in Lijiang. Heqing strains and Lijiang strains were in the same cluster in MST and only VNTR loci N2117 and M23 of Heqing strains were different from that of Lijiang strains. Conclusion: The Y. pestis strains isolated from Heqing in 2017 were highly homogenous with the strains isolated from wild rodents in plague focus in Lijiang, and Heqing plague might be the result of further southward spread of Lijiang plague.

Association between central obesity and risk for heart disease in adults in China: a prospective study / 中华流行病学杂志

Objective: To understand the association between central obesity, assessed by waist circumference, and the risks for ischemic heart disease (IHD), major coronary event (MCE), and IHD death. Methods: After excluding participants with heart disease, stroke, cancer, COPD, and diabetes at baseline survey, we included a total of 428 595 participants from the China Kadoorie Biobank for the analysis. The baseline survey was conducted from June 2004 to July 2008. We used Cox proportional hazards model to estimate the hazard ratio (HR) and 95%CI. Results: During an average 9.1 years of follow-up (3 803 637 person-years), we documented 26 900 incident cases of IHD, 4 320 cases of MCE, and 2 787 of deaths from IHD. After adjustment for possible confounders and BMI, central obesity was found to be associated with increased risks for IHD, MCE, and IHD death. The adjusted HRs (for the participants who had waist circumference of 85.0-89.9 cm in men and 80.0-84.9 cm in women were 1.13 (95%CI: 1.09-1.17) for IHD, 1.15 (95%CI: 1.05-1.26) for MCE and 1.11 (95%CI: 0.98-1.24) for IHD death. The respective HRs for those central obese participants (men ≥90.0 cm, women ≥85.0 cm) were 1.29 (95%CI: 1.24-1.34), 1.30 (95%CI: 1.17-1.44) and 1.32 (95%CI: 1.16-1.51). Further stratification analysis according to BMI showed that the risks for incident IHD, MCE, and IHD death increased along with the increase of waist circumference even in the participants with normal weight. Conclusion: This large-scale prospective study revealed that central obesity was an independent risk factor for IHD in adults in China, and the risk of IHD would increase with the increase of waist circumference.

Association between tea drinking and stroke in adults in Zhejiang province: a prospective study / 中华流行病学杂志

Objective: To prospectively explore the association between tea drinking and incidence of stroke of adults of Zhejiang province. Methods: After excluding participants with heart disease, stroke, cancer and diabetes at baseline study, 53 916 participants aged 30-79 years in the China Kadoorie Biobank (CKB) study from Tongxiang were included for final analysis. Cox regression model was used to estimate the hazard ratio (HR) for the association of tea drinking with incident stroke. Results: The main type of drinking tea was black tea (79.78%), followed by green tea (20.08%). Of the 53 916 participants, the proportion of participants who drank tea at least once per week was 31.27%. The corresponding proportions for men and women were 60.24% and 10.30%, respectively. Among 391 512 person-years of the follow-up program (median 7.26 years), a total of 1 487 men and 1 769 women were diagnosed with stroke. After adjusting for socio-demographic status, lifestyle, BMI, waist circumference, and systolic blood pressure, HR for incident stroke decreased with the increase of daily average tea consumption amount (P=0.000 6). Compared with participants who did not drink tea weekly, the HRs for incident stroke in those consuming tea 0.1-, 3.0- and ≥5.0 g/d were 0.93 (95%CI: 0.85-1.00), 0.88 (95%CI: 0.77-0.99) and 0.79 (95%CI: 0.69-0.89), respectively. The HRs for incident stroke in smokers and non-smokers who consumed tea ≥5.0 g/d were 0.71 (95%CI: 0.59-0.86) and 0.97 (95%CI: 0.77-1.21), respectively, compared with current smokers and non-smokers who did not drink tea weekly (P=0.040 0). The corresponding HRs for alcohol drinkers and non-drinkers were 0.96 (95%CI: 0.76-1.22) and 0.70 (95%CI: 0.58-0.84), respectively (P=0.040 0). The corresponding HRs for central obese persons and non-central obese persons were 0.60 (95%CI: 0.44-0.81) and 0.86 (95%CI: 0.73-1.01), respectively (P=0.040 0). Conclusion: Tea drinking had an effect on reducing the possibility of incident stroke, especially among those who were current smokers, non-alcohol drinkers and central obese.

Effect of famine exposure on the risk of chronic disease in later life among population in Harbin / 中华流行病学杂志

Objective: To study the relations between famine exposure and the risk of chronic diseases as diabetes mellitus, obesity, hypertension, coronary heart disease and stroke in the population of Harbin. Methods: Our data was collected from the baseline survey-the China Kadoorie Biobank project (CKB) in Harbin. Retrospective cohort study design was used. Related risks on chronic diseases including diabetes mellitus, obesity, hypertension, coronary heart disease and stroke, were compared among the famine exposed or non-exposed people, respectively by logistic analysis method. Results: After adjusted for factors as age, sex, physical activity, smoking, alcohol intake, diet, family history of diseases, it appeared that the factor 'famine exposure' had increased the risks of diseases as obesity (OR=1.204, 95%CI: 1.104-1.313, P<0.01), hypertension (OR=1.315, 95%CI: 1.210-1.429, P<0.01) and coronary heart disease (OR=1.495, 95%CI: 1.369-1.632, P<0.01). The lower the age of population being exposed to famine, the greater the risk of the development of all kinds of chronic diseases. Conclusions: Famine exposure appeared a risk factor for obesity, hypertension, and coronary heart disease. It is of great significance to ensure the life-long nutrition of the people, especially in the early and adolescent stages, to prevent obesity, hypertension, and coronary heart disease in their later lives.

Epidemiological characteristics of household fuel use in 10 areas of China / 中华流行病学杂志

Objective: To describe the characteristics of cooking and heating fuel use in participants from the China Kadoorie Biobank (CKB) study. Methods: The CKB study recruited 512 891 adults from 10 areas in China during 2004-2008. Information on cooking fuel and heating fuel was collected using a questionnaire in baseline survey. The proportions of various fuels used in different areas, in different populations, and at different time points were calculated and compared. Results: Overall, 52.1% participants used solid fuel for cooking or heating. Rural areas had higher prevalence of solid fuel use than urban areas. The percentage of participants using solid fuel for cooking was 36.1% (coal 20.1%, wood/charcoal 16.0%); The percentage of participants using solid fuel for heating was 36.7% (coal 22.7%, wood/charcoal 14.0%). The prevalence of solid fuel use and the fuel type mainly used varied widely across 10 areas. The proportion of clean fuel use was lower in less-educated and lower-income people. Household coal and wood/charcoal use showed a declining trend, which was more remarkable in urban areas. Conclusion: There are still a large number of rural residents and people with low income relying on solid fuel in China, which is a serious public health concern.

Study on acute HIV-1 infection in men who have sex with men in Tianjin / 中华流行病学杂志

Objective: To understand the immunological and virological characteristics of HIV-1 infected men who have sex with men (MSM) in the acute phase in Tianjin and evaluate the effects of the fourth generation HIV ELISA and the P24 ELISA for acute HIV-1 infected samples. Methods: From October 2015 to October 2016, MSM were recruited through the community-based organizations in Tianjin. All the participants received rapid HIV test, positive samples were confirmed by Western Blot and negative samples underwent pooled nucleic acid testing. The participants with HIV-1 RNA reactive result underwent testing for viral load and T-cell count after second blood collection. Acute HIV-1 infection was defined as negative rapid HIV test result and the positive results of two HIV RNA tests, then the sensitivity were compared between the fourth generation HIV ELISA and the P24 ELISA to detect the initial HIV-1 RNA positive samples. Results: Among 3 016 MSM screened, 193 were positive in rapid HIV test. Western blot testing indicated that 179 cases were HIV positive, 7 cases were HIV indeterminate and 7 cases were negative. Of 2 823 sero-negative cases, 17 were acute HIV-1 infections. The HIV-1 infection rate was 6.53% (197/3 016) and the acute HIV-1 infection rate was 0.56% (17/3 016), with an average viral load of (5.63±1.50) log(10) copies/ml, an average CD(4) count of (442.82±268.17) cells/μl, an average CD(8) count of (1 069.65±668.22) cells/μl and an average CD(4)/CD(8) ratio of (0.49±0.25). Higher viral load, CD(4) and CD(4)/CD(8) ratio were seen in the acute HIV-1 infection group compared with the chronic HIV-1 infection group (U=148, P<0.01; U=272, P=0.042 and t=3.147, P=0.005). Demographic characteristics were similar between two groups, except the occupation (χ(2)=11.016, P=0.026). The sensitivity of P24 ELISA was higher than the fourth generation HIV ELISA in the HIV-1 detection for acute infection (Fisher's exact test, P=0.017). Conclusions: MSM are at risk for acute HIV-1 infection. Screening for acute HIV-1 infection with P24 ELISA would increase the sensitivity of diagnosis and reduce HIV transmission in MSM.