Serological evaluation and antibody prediction model for inactivated COVID-19 vaccination in school children / 上海预防医学

ObjectiveTo determine the serum antibody level and risk factors in the adolescent population in a county in Zhejiang Province， following the immunization with inactivated COVID-19 vaccine， and to construct a prediction model for antibody concentration. MethodsWe conducted the study in a county in Zhejiang Province， employing a stratified cluster random sampling strategy in school children who had received the inactivated COVID-19 vaccine. Data on gender， age， type of vaccine， and time of vaccination was collected. Serum samples were also collected to test for anti-S and N IgG antibody against the SARS-CoV-2 by using chemiluminescent immunoassay （CLIA）. Risk factors were determined to construct a prediction model for antibody concentration. ResultsThe IgG antibody concentration was significantly higher in girls， those who received two doses， and those who had simply received the KX vaccine . It decreased with age and time interval between the sampling and last vaccination. The prediction model constructed by random forest regression in the study had a better model fit and predictive ability than that by the multivariable linear stepwise regression. ConclusionGender， age， vaccination dose， type of vaccine， and time of vaccination are associated with vaccination effectiveness of inactivated COVID-19 vaccines in adolescents. Prediction model could predict the antibody level in the vaccinated population， which can provide a new tool for better evaluation of vaccination effectiveness against emerging infectious diseases in future.

Efficacy of different questionnaires in screening COPD in the communities of Songjiang District， Shanghai / 上海预防医学

ObjectiveTo evaluate the efficacy of three screening questionnaires for COPD in the community residents of Songjiang District， Shanghai， and to provide a basis for selecting COPD screening questionnaire and process that are more suitable. MethodsCommunity residents aged 40 years or over were randomly selected from the Shanghai Suburban Adult Cohort and Biobank for the study with screening questionnaires and spirometry. Questionnaires included the COPD screening questionnaire （COPD-SQ）， the COPD population screener （COPD-PS） and the revised COPD diagnostic questionnaire （revised-CDQ）. Evaluation of the efficacy of these questionnaires was based on the area under the receiver operating characteristic curve （AUC） of the subjects. DeLong test was used to compare the accuracy of different questionnaires； Z test was used to compare the accuracy of different cut-off values for the same questionnaire. ResultsAmong 3 184 community residents， a total of 259 （8.1%） COPD patients were screened by spirometry. AUC values of these 3 screening questionnaires were >0.7 indicating that they were reliable COPD screening tools. The sensitivity and specificity of the questionnaires at the recommended cut-off values were COPD-SQ （63.7% and 72.2%）， COPD-PS （12.0% and 96.1%）， and revised CDQ （78.8% and 52.7%）， with the COPD-SQ having the highest screening accuracy （AUC=0.754）. The optimal and recommended cut-off values for the three questionnaires differed in this population， but the difference in accuracy was statistically significant only for COPD-PS. The optimal cut-off values for the three questionnaires differed between male and female， and the sensitivity and accuracy of COPD-SQ and COPD-PS improved when lower cut-off values were used for women. The AUC was greater when two questionnaires were utilized simultaneously for screening， but the differences were not statistically significant. ConclusionThe COPD-SQ is recommended for primary COPD screening； a lower cut-off value for women should be considered. The COPD screening questionnaire needs to be further improved for the early diagnosis and treatment of COPD patients.

Trend of antibiotics usage among outpatients in primary public medical institutions in a county of Zhejiang Province， from 2015 to 2020 / 上海预防医学

ObjectiveTo understand the usage of antibiotics in outpatients in a county of Zhejiang Province from 2015 to 2020， so as to provide a basis for further standardizing the clinical application of antibiotics in this region. MethodsOutpatient records and prescription records of 146 public medical institutions from 2015 to 2020 were extracted from the electronic medical record data sharing platform system of medical institutions in a county of Zhejiang Province. The utilization rates and the number of types of antibiotics used in outpatient patients were described. According to the drug anatomy， therapeutic and chemical classification system （ATC）， clinical application classification and dosage form， the use status of different types of antibiotics was observed. The annual percentage change （APC） was used to analyze the time trend of antibiotic use. Among the antibiotic prescriptions in each year， the proportions of prescriptions aimed for different use reasons and patients were compared to analyze the changes in the structures of antibiotic prescriptions. ResultsDuring 2015‒2020， a total of 2 861 438 prescriptions were issued in146 primary public medical institutions in this county， including 314 642 prescriptions for antibiotics， and the overall utilization rate of antibiotics was 11%. The utilization rate of antibiotics showed a decreased trend across the years （from 14.23% in 2015 to 7.59% in 2020，APC=-11.51%， 95%CI=-0.01%‒-21.7%， t=-12.05， P<0.001） and an obvious seasonal variation character （higher in winter and spring， lower in summer and autumn）. Cefoxitin sodium for injection was the most used antibiotic in 2015， and cefuroxime was the most used antibiotic from 2015 to 2020， respectively. The utilization rates of cephalosporins （APC=-11.06%， 95%CI=0‒-20.89%， t=-22.233， P<0.001）， quinolones （APC=-9.74%， 95%CI=0‒-18.53%， t=-7.652， P=0.002）， macrolides （APC=-17.52%， 95%CI=0‒-17.52%， t=-3.626， P=0.022） and lincoamides （APC=-49.01%， 95%CI=0‒-74%， t=-3.35， P=0.029） showed a decreasing trend across the years. There were differences in the distribution of drug use reasons （χ2=9 458.427， P<0.001）， as well as the age （χ2=5 421.709， P<0.001） and sex （χ2=245.322， P<0.001） of patients. During the observation period， 50.69% of antibiotic prescriptions were used to treat respiratory diseases， with the highest proportion of 57.67% in 2015 and the lowest proportion of 34.93% in 2020. 58.37% of patients were aged 50‒70 years， with a decreasing proportion of patients under 50 years （17.83% in 2015， 6.64% in 2020） and an increasing proportion of patients over 70 years （24.1% in 2015， 38.41% in 2020）. ConclusionThe utilization rate of antibiotics used in outpatients from primary public medical institutions in a county of Zhejiang Province shows a decreasing trend across the years， but higher than that of secondary and above hospitals in China， and also higher than that of primary medical institutions in economically-developed areas. The management and monitoring of the clinical use of antibiotics in the county should be actively strengthened.

Spatial distribution characteristics of the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody in Hunan Province in 2020 / 中国血吸虫病防治杂志

OBJECTIVE@#To investigate the spatial distribution characteristics of the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody, and to examine the correlation between the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody in Hunan Province in 2020, so as to provide insights into advanced schistosomiais control in the province.@*METHODS@#The epidemiological data of schistosomiasis in Hunan Province in 2020 were collected, including number of permanent residents in survey villages, number of advanced schistosomiasis patients, number of residents receiving serological tests and number of residents seropositive for anti-Schistosoma antibody, and the prevalence advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody were descriptively analyzed. Village-based spatial distribution characteristics of prevalence advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody were identified in Hunan Province in 2020, and the correlation between the revalence advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody was examined using Spearman correlation analysis.@*RESULTS@#The prevalence of advanced schistosomiasis was 0 to 2.72% and the seroprevalence of anti-Schistosoma antibody was 0 to 20.25% in 1 153 schistosomiasis-endemic villages in Hunan Province in 2020. Spatial clusters were identified in both the prevalence of advanced schistosomiasis (global Moran's I = 0.416, P < 0.01) and the seroprevalence of anti-Schistosoma antibody (global Moran's I = 0.711, P < 0.01) in Hunan Province. Local spatial autocorrelation analysis identified 98 schistosomiasis-endemic villages with high-high clusters of the prevalence of advanced schistosomiasis, 134 endemic villages with high-high clusters of the seroprevalence of anti-Schistosoma antibody and 36 endemic villages with high-high clusters of both the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody in Hunan Province. In addition, spearman correlation analysis showed a positive correlation between the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody (rs = 0.235, P < 0.05).@*CONCLUSIONS@#There were spatial clusters of the prevalence of advanced schistosomiasis and seroprevalence of anti-Schistosoma antibody in Hunan Province in 2020, which were predominantly located in areas neighboring the Dongting Lake. These clusters should be given a high priority in the schistosomiasis control programs.

Spatio-temporal distribution of emerging snail-infested sites in different environmental types in Yunnan Province / 中华地方病学杂志

Objective:To explore the spatial and temporal distribution patterns of emerging snail-infested sites in different environmental types in Yunnan Province.Methods:The data of snail-infested sites in Yunnan Province from 1950 to 2014 (from Yunnan Institute for Endemic Diseases Control and Prevention), were collected and sorted out, a spatial and temporal database on the distribution of emerging snail-infested sites were established, and the changes in the spatial and temporal distribution of emerging snail-infested sites in different environments types (ditches, tangerines, paddy fields, dry land, beaches and other environments) were studied by using spatial autocorrelation analysis and scanning statistics analysis.Results:From 1950 to 2014, the annual number of emerging snail-infested sites in Yunnan Province reached a peak (1 730) in 1955 and then showed a fluctuating downward trend. From 1993 to 2014, the number of emerging snail-infested sites remained below 100, and increased to 160 and 131, respectively, in 2004 and 2013. The longest mean duration of 43.85 years was recorded for the beaches environment for emerging snail-infested sites, followed by the paddy fields environment with a mean duration of 37.01 years, and the shortest mean duration of 20.44 years for the tangerines environment. Spatial autocorrelation analysis showed that there was a positive spatial correlation between the duration of emerging snail-infested sites of different environmental types (global Moran's I ranged from 0.43 to 0.64, P < 0.05). Scanning statistics analysis showed that emerging snail-infested sites of different environmental types had spatial and temporal aggregation ( P < 0.001), with 3- 6 clusters of statistically significant aggregation detected respectively. Conclusion:The emerging snail-infested sites in different environments types in Yunnan Province have spatial and temporal aggregation, and it is necessary to strengthen monitoring and prevention and control of the aggregation areas of different environment types to prevent further spread of the snail.

Optimization of the medium and fermentation condition for the Penicillium aurantiocandidum Z12 strain with molluscicidal actions against Oncomelania hupensis / 中国血吸虫病防治杂志

Objective To optimize the culture and fermentation conditions of the Penicillium aurantiocandidum Z12 strain, a fungal strain with molluscicidal actions against Oncomelania hupensis, so as to provide the basis for the research and development of molluscicidal active substances from the P. aurantiocandidum Z12 strain and its fermentation broth and large-scale fermentation. Methods The carbon source, nitrogen source and mineral salts were identified in the optimal culture medium for the P. aurantiocandidum Z12 strain with a single-factor experiment to determine the best fermentation condition for the P. aurantiocandidum Z12 strain. Factors that significantly affected the growth of the P. aurantiocandidum Z12 strain were identified using the Plackett-Burman design, and the best range of each factor was determined using the steepest climb test. Response surface analyses of temperature, pH value, seeding amount and liquid-filling quantity were performed using the Box-Behnken design to create a regression model for fermentation of the P. aurantiocandidum Z12 strain to identify the optimal culture medium. Results Single-factor experiment preliminarily identified the best culture medium and conditions for the P. aurantiocandidum Z12 strain as follows: sucrose as the carbon source at approximately 20 g/L, tryptone as the nitrogen source at approximately 5 g/L, K2HPO4 as the mineral salt at approximately 5 g/L, initial pH at approximately 8, temperature at approximately 28 °C, seeding amount at approximately 6%, and liquid-filling quantity at approximately 50 mL/100 mL. Plackett-Burman design showed that factors that significantly affected the growth of the P. aurantiocandidum Z12 strain included temperature (t = −5.28, P < 0.05), seeding amount (t = 5.22, P < 0.05), pH (t = −4.30, P < 0.05) and liquid-filling quantity (t = −4.39, P < 0.05). Steepest climb test showed the highest mycelial growth at pH of 7.5, seeding amount of 8%, and liquid-filling quantity of 40 mL/100 mL, and this condition was selected as the central point of response surface analysis for the subsequent optimization of fermentation conditions. Response surface analyses using the Box-Behnken design showed that the optimal conditions for fermentation of the P. aurantiocandidum Z12 strain included sucrose at 15 g/L, tryptone at 5 g/L, K2HPO4 at 5 g/L, temperature at 28.2 °C, pH at 7.5, seeding amount at 10%, and liquid-filling quantity at 35.8 mL/100.0 mL, resulting in 0.132 g yield of the P. aurantiocandidum Z12 strain. Conclusion The optimal culture condition for the P. aurantiocandidum Z12 strain has been identified, and the optimized culture medium and fermentation condition may effectively improve the fermentation yield of the P. aurantiocandidum Z12 strain.

Latent tuberculosis infection status and its risk factors among tuberculosis-related health-care workers in Shanghai / 上海预防医学

ObjectiveTo obtain the status of latent tuberculosis infection （LTBI） among tuberculosis （TB）-related health-care workers （HCWs） in Shanghai， and to explore the risk factors related to TB infection. MethodsA multi-center cross-sectional study was conducted by recruiting medical workers from multiple designated TB hospitals， centers for disease control and prevention， and community health service centers in Shanghai. Each subject was required to complete a questionnaire and to provide a blood sample for TB infection test. Univariate and multivariate analysis ware made in order to find risk factors relating to TB infection. ResultsA total of 165 medical workers were recruited， and the proportion of TB infection was 16.36% （95%CI： 11.49%‒22.76%）. Multivariate logistic analysis showed that clinical doctors and nurses （adjusted OR=9.756， 95%CI： 1.790‒53.188）， laboratory staffs （adjusted OR=78.975， 95%CI： 8.749‒712.918）， and nursing and cleaning workers （adjusted OR=89.920， 95%CI： 3.111‒2 598.930） had higher risk of TB infection. ConclusionThe overall LTBI prevalence among TB-related HCWs is low. However， working as doctors， nurses， laboratory staffs， nursing workers and cleaning workers are risk factors of TB infection. TB-related HCWs who work at hospitals are at risk of TB infection comparing to medical staffs who work outside hospitals.

Distribution characteristics of antibiotic resistance genes in the domestic water of residents in Haimen， Jiangsu Province / 上海预防医学

ObjectiveAntibiotic resistance genes （ARGs） have received wide attention all over the world. The purpose of this study was to explore the bacterial community structure， the types and levels of antibiotic resistance genes in a water body in east China， and to compare and analyze the characteristics of microbial species distribution and antibiotic resistance gene distribution in various water environments. MethodsA total of 10 households in Haimen City， Jiangsu Province were selected and their surrounding water environment samples were collected. 21 water samples including river water （4）， Mingou water （9） and well water （8） were collected for metagenomics sequencing， assembled with MetaWRAP， annotated with CARD database， and analyzed with R software. ResultsIn various water bodies， the dominant bacteria phyla was Proteobacteria， the dominant bacteria genera were Deuterostomia， Pseudomonas， Flavobacteriales and Streptomycetaceae. The ARGs annotated were mainly composed of quinolones， aminoglycosides， macrolides and beta-lactams antibiotic resistance genes. The top four relative abundance of resistance genes were macB， RanA， evgS and TxR， The average absolute abundance and expression of resistance genes in well water and Mingou water were higher than those in river water. ConclusionMultiple ARGs are detected to varying degrees in well water， river water， and Mingou water bodies， and the expression of resistance genes in well water and Mingou water bodies is higher than that in river water bodies， possibly due to human production and living activities.

Coverage and effectiveness of COVID-19 vaccines among people aged 60 years and above in Changning District of Shanghai / 上海预防医学

ObjectiveTo assess the coverage and effectiveness of COVID-19 vaccines in the elderly. MethodsThis study was conducted in Changning District of Shanghai， targeting people aged 60 years and above. Vaccination data between 21 December 2020 and 28 February 2022 was retrieved from the Shanghai Collective Immunization System. Information on confirmed cases of COVID-19 from March 2022 through May 2022 was collected from the National Notifiable Diseases Reporting System. Vaccine effectiveness was calculated using the screening method. ResultsAs of 28 February 2022， 69.89% of people aged ≥60 years had received ≥1-dose vaccine， 63.80% had received full primary vaccination and 31.91% had received a booster dose. Vaccination coverage declined over age， with the lowest coverage in the elderly aged ≥80 years. Moreover， COVID-19 vaccination provided the highest protection against severe/critical illness and death due to the Omicron variants in the elderly aged ≥60 years. Full primary vaccination showed 96.15%（95%CI：84.15‒99.06）of vaccine effectiveness and booster vaccination showed 100% of the effectiveness against severe/critical COVID-19 and death. ConclusionsFull primary and booster vaccination coverage in the elderly is low， especially in those aged 80 and above. Our study finds high protection against COVID-19 associated severe/critical illness and death from both full primary and booster vaccination of inactivated COVID-19 vaccines in the elderly aged ≥60 years.

Serological evaluation of immune effect of inactivated COVID-19 vaccine in adult population in Deqing County， Huzhou City， Zhejiang Province / 上海预防医学

ObjectiveTo investigate the specific anti-SARS-CoV-2 antibody in adults and above after initial vaccination with inactivated COVID-19 vaccine， and determine the influencing factors. MethodsIn this study， residents aged 18 and above who had completed two doses of inactivated COVID-19 vaccine in Deqing County， Huzhou City， Zhejiang Province were included. Information such as gender， age， type of vaccine and vaccination time were collected， and serum specimens were sampled. Anti-SARS-CoV-2 receptor binding domain （RBD） antibody was quantitatively examined by enzyma-linked immunosorbent assay （ELISA） and influencing factors were determined. ResultsThe median concentration of anti-SARS-CoV-2 IgG antibody in the residents vaccinated with an inactivated booster vaccine was higher than that in those vaccinated with only two doses of COVID-19 vaccine or single dose （P<0.05）. The median concentration of IgG antibody in males was 9.73 （4.01‒23.70） RU‧mL-1， lower than 17.76 （7.07‒49.23） RU‧mL-1 in females （P<0.05）. The median concentration in the residents vaccinated with BBIBP-CorV （Sinopharm） was 6.53 （0.97‒13.69） RU‧mL-1， which was lower than that in those vaccinated with CoronaVac （Sinovac） that was 17.29 （8.54‒43.73） RU‧mL-1 （P<0.05）. The median concentration in those with BBIBP-CorV was also lower than 12 （5.45‒40.06） RU‧mL-1 in those with heterologous booster vaccine （P<0.05）. The median concentration was 9.73 （3.83‒23.63） RU‧mL-1 in the residents with an interval of more than 6 months from the second dose， which was lower than 14.66 （6.36‒35.98） RU‧mL-1 in those with an interval of 3‒6 months （P<0.05）. Moreover， immune effect was better in females （χ²=16.464， P<0.05）， 18‒45 years（χ²=7.158， P<0.05）， and those vaccinated with CornaVac （χ²=49.637， P<0.05）， while decreased in those with an interval of more than 6 months from the second dose （χ²=8.447， P<0.05）. ConclusionGender， age， and type of vaccine may affect the effect of immunization. The COVID-19 vaccination shows an acceptable immunogenicity in adults； however， it declines in 6 months after vaccination. It warrants strengthening the booster vaccination to maintain the immune response.

False negatives of screening in large-scale population / 上海预防医学

ObjectiveTo explore the changing trend of negative predictive value and number of false negatives in screening tests under the condition of low infection rate of infectious diseases. MethodsAssuming that the population is 20 million， to calculate the negative predictive value， numbers of true negatives and false negatives of the combination of different sensitivity （75.0%， 80.0%， 85.0%， 90.0%， 95.0%， 99.0%） and specificity （90.0%， 95.0%， 99.0%， 99.9%） when the disease infection rate of the population is 0.10%， 1.0% and 5.0% respectively. ResultsWhen the population infection rate is 0.1%， with the screening test sensitivity ≥75.0% and specificity ≥90.0%， the number of true negatives in 20 million people is about 17.98‒19.96 million. When the sensitivity is 75.0%， the negative predictive value is 99.972%‒99.975%， and the number of false negatives is 5 000； When the sensitivity increases to 99.0%， the negative predictive value is 99.999%， and the number of false negatives decreases to 200. When the population infection rate is 1.0%， a screening test with sensitivity ≥75.0% and specificity ≥90.0% can detect about 17.82‒19.78 million true negatives in 20 million population. When the sensitivity is 75.0%， the negative predictive value is 99.720%‒99.748%， and the number of false negatives is 50 000； When the sensitivity increases to 99.0%， the negative predictive value increases to 99.990%， and the number of false negatives decreases to 2 000. When the population infection rate is 5.0%， with sensitivity ≥75.0% and specificity ≥90.0%， the number of true negatives in 20 million people is about 17.10‒18.98 million； when the sensitivity is 75.0%， the negative predictive value is 98.559%‒98.700%， and the number of false negatives can reach 250 000； When the sensitivity is 99.0%， the negative predictive value increases to 99.942%‒99.947%， and the number of false negatives decreases to 10 000. The lower the infection rate of the population， the fewer false negatives will appear in the screening. ConclusionThe number of false negatives in large-scale screenings increases exponentially with the increase of infection rate. Screenings should be carried out as early as possible in a pandemic of infectious diseases， so as to control the spread of the pandemic as soon as possible.

Needs for curriculum and specialty development of public health nursing： an investigation of medical students during the COVID-19 pandemic / 上海预防医学

ObjectiveThe purpose of this study is to investigate and analyze the needs of public health nursing courses and specialty settings under the COVID-19 pandemic. MethodsA total of 576 medical students majored in clinical medicine， preventive medicine， pharmacy， and nursing from a Shanghai university participated in this survey. The Questionnaire Star App was used to collect students' knowledge， attitude and behavior about public health safety and emergency preparedness， public health related curriculum and public health nursing specialty， through self-administered approach. ResultsThere were significant differences in the knowledge of emergency nursing among students with different majors and grades. Over 80% of the participants agreed that "public health popularization should be strengthened". Over 60% were willing to "invest more time and energy in learning and understanding public health-related disease prevention and control knowledge". The school has carried out corresponding training or practice activities in public health education. Compared with nursing major， students with other majors performed better in paying attention to and participating in the training or practical activities of public health education. More than 70% agreed that it was necessary to set up public health nursing courses， especially nursing specialty， with the approval rate as high as 92.3%. Students believed that "2 class hours per week"， and "1/10 of the total class hours" was appropriate. In terms of course teaching， nursing students put forward more expectations on teaching objectives， methods， and characteristic courses. ConclusionUndergraduates lack knowledge of public health nursing， but most of them， especially nursing undergraduates， have a strong desire to learn and have a positive attitude towards opening public health nursing courses. However， there are still problems such as insufficient attention to and insufficient understanding of the courses. More efforts should be made to enhance the public health nursing education on public health emergencies， optimize the relevant settings of courses， so as to train nursing personnel suitable for the current health service needs in China.

Effect of exposure to typical phthalate esters on estrogen homeostasis during pregnancy / 上海预防医学

ObjectiveTo study the relationship between the exposure to two kinds of phthalate esters （PAEs） ［Di-N-butyl phthalate，（DBP） and Di-（2-ethylhexyl）phthalate （DEHP）］ and estrogen homeostasis in pregnant women. MethodsIn 2021， we classified the Jiading District of Shanghai into five geographical areas， east， west， south， north and central. A total of 151 pregnant women from each area were selected for questionnaire survey， with random urine samples during first， second， and third trimesters collected. A DBP metabolite ［Mono-N-butyl phthalate （MBP）］ and two DEHP metabolites ［Mono（2-ethylhexyl） phthalate （MEHP）， Mono（2-ethyl5-oxohexyl） phthalate， （MEOHP）］ and three estrogens ［estrone （E1）， 17β -estradiol （E2）， and estriol （E3）］ in urine were determined by ultra-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry. After a natural logarithmic transformation of PAEs metabolite levels and estrogen concentration， multivariable linear regression was used to control potential confounders and determine the relationship between PAEs metabolite levels and estrogen concentration. ResultsThe detection rates of three PAEs metabolites in urine of pregnant women were more than 98%. The median corrected concentrations of MBP， MEHP and MEOHP were 5.18， 0.59 and 4.23 mg·kg-1， respectively. During the whole pregnancy， MEOHP was positively correlated with E1 （β=0.450， 95%CI： 0.057‒0.844）， and MBP was positively correlated with E3 （β=0.250， 95%CI： 0.034‒0.465）. Stratified by trimesters， MBP was positively correlated with E3 in the first trimester （β=0.428， 95%CI： 0.103‒0.752）. MEOHP was positively correlated with E1 in the second trimester （β=0.734， 95%CI： 0.130‒0.752）， and had a possitive trend with E1 in the third trimester （β=0.744， 95%CI： -0.140‒1.629）. In addition， MEHP had a negative correlation with E1 in the second trimester （β=-0.498， 95%CI： -1.063‒0.066）. MEOHP had a positive correlation trend with E2 （β=0.628， 95%CI： -0.101‒1.356） in the third trimester. ConclusionPAEs exposure may interfere with estrogen homeostasis during pregnancy and differs by trimesters. Given the cross-sectional nature of this study， it warrants further study to validate the findings.

Progress in the study of polymyxin resistance and its mechanism / 上海预防医学

Drug-resistant bacteria have become a serious threat to human health. Polymyxin has shown strong bactericidal activity to some Gram-negative and Gram-positive bacteria that are resistant to antibiotics， and has become a last-resort treatment option against a variety of multi-drug resistant bacteria. However， due to the abuse of polymyxin in animal breeding， the drug resistance rate of polymyxin in human population has significantly increased. In order to further understand the mechanism of polymyxin resistance， and to take measures to reduce the incidence of polymyxin resistance in the population， this paper reviewed the progress in research of the antibacterial mechanism of polymyxin， the prevalence of polymyxin resistance in the population， the mechanism of polymyxin resistance， and its transmission mode.

Progress in the study of polymyxin resistance and its mechanism / 上海预防医学

Drug-resistant bacteria have become a serious threat to human health. Polymyxin has shown strong bactericidal activity to some Gram-negative and Gram-positive bacteria that are resistant to antibiotics， and has become a last-resort treatment option against a variety of multi-drug resistant bacteria. However， due to the abuse of polymyxin in animal breeding， the drug resistance rate of polymyxin in human population has significantly increased. In order to further understand the mechanism of polymyxin resistance， and to take measures to reduce the incidence of polymyxin resistance in the population， this paper reviewed the progress in research of the antibacterial mechanism of polymyxin， the prevalence of polymyxin resistance in the population， the mechanism of polymyxin resistance， and its transmission mode.

False positives of screening in large-scale population with low infection rate of an infectious diseasea： a modeling analysis / 上海预防医学

ObjectiveTo explore the positive predictive value （PPV） and false positive （FP） number of screening test in mass testing when the prevalence of infection is low. MethodsAssuming a population of 20 million with the prevalence of disease infection ranging from 0.1% to 5.0%， PPV， true positive （TP） and FP numbers were calculated under different scenarios of combination of sensitivity （99.0%， 99.5%， and 100.0%） with specificity （97.0%， 97.5%， 98.0%， 98.5%， 99.0%， 99.5%， and 99.9%）. ResultsFor low infection prevalence （≤5.0%）， specificity has a greater impact on PPV than sensitivity； with the decrease of infection prevalence， the increase in PPV elevates when the specificity increases. When the infection prevalence is >1.0%， the closer the specificity is to 99.9%， the closer the PPV is to 100.0%. However， when the infection prevalence is <1.0%， the maximum PPV is only about 90.0%. When the infection rate is 0.1%， a screening test with more than 99.0% sensitivity could detect about 20 thousand TP cases in a population of 20 million. Additionally， the FP and PPV are estimated to be 599 thousand and 3.2% if the specificity is 97.0%， and 20 thousand and 50.0% if the specificity is 99.9%. When the infection rate is 1.0%， a screening test with ≥99.0% sensitivity and ≥97.0% specificity could detect about 0.198‒0.200 million TP cases； and the number of FP decreases from 594 thousand to 20 thousand when the specificity increases from 97.0% to 99.9%. When the infection rate is 5.0%， a screening test with ≥99.0% sensitivity and ≥97.0% specificity could detect about 0.99‒1.00 million TP cases； and the number of FP decreases from 570 thousand to 19 thousand when the specificity increases from 97.0% to 99.9%. When the infection prevalence is ≤5.0% in a total population of 20 million， there are about 20，000 FP cases even if the sensitivity and specificity reach the maximum values of 100.0% and 99.9%， respectively. ConclusionWhen the population is large and the infection prevalence is low， in addition to improving the specificity of the screening test in mass testing， the problem of a large number of false positives cannot be ignored.

Evolution and variation of 2019-novel coronavirus

BackgroundThe current outbreak caused by novel coronavirus (2019-nCoV) in China has become a worldwide concern. As of 28 January 2020, there were 4631 confirmed cases and 106 deaths, and 11 countries or regions were affected. MethodsWe downloaded the genomes of 2019-nCoVs and similar isolates from the Global Initiative on Sharing Avian Influenza Database (GISAID and nucleotide database of the National Center for Biotechnology Information (NCBI). Lasergene 7.0 and MEGA 6.0 softwares were used to calculate genetic distances of the sequences, to construct phylogenetic trees, and to align amino acid sequences. Bayesian coalescent phylogenetic analysis, implemented in the BEAST software package, was used to calculate the molecular clock related characteristics such as the nucleotide substitution rate and the most recent common ancestor (tMRCA) of 2019-nCoVs. ResultsAn isolate numbered EPI_ISL_403928 showed different phylogenetic trees and genetic distances of the whole length genome, the coding sequences (CDS) of ployprotein (P), spike protein (S), and nucleoprotein (N) from other 2019-nCoVs. There are 22, 4, 2 variations in P, S, and N at the level of amino acid residues. The nucleotide substitution rates from high to low are 1{middle dot}05 x 10-2 (nucleotide substitutions/site/year, with 95% HPD interval being 6.27 x 10-4 to 2.72 x 10-2) for N, 5.34 x 10-3 (5.10 x 10-4, 1.28 x 10-2) for S, 1.69 x 10-3 (3.94 x 10-4, 3.60 x 10-3) for P, 1.65 x 10-3 (4.47 x 10-4, 3.24 x 10-3) for the whole genome, respectively. At this nucleotide substitution rate, the most recent common ancestor (tMRCA) of 2019-nCoVs appeared about 0.253-0.594 year before the epidemic. ConclusionOur analysis suggests that at least two different viral strains of 2019-nCoV are involved in this outbreak that might occur a few months earlier before it was officially reported.

A cohort study on the association between dynamics of thyroid volume and the changes of physical growth as well as the comparison of different thyroid volume indexes in school-aged children / 中华流行病学杂志

Objectives: To investigate the association between the dynamics of thyroid volume and the changes of physical growth in school-aged children as well as to compare the applicability of different thyroid volume indexes, so as to explore more reliable methods for the assessment of thyroid volume. Methods: In October 2012, a multi-stage cluster sampling method was used to select a primary school in Minhang district of Shanghai, Haimen city of Jiangsu province and Yuhuan city of Zhejiang province, respectively. In these areas, a total number of 784 students aged 8-10 years were enrolled in the cohort. Demographic data was collected, while height and weight were measured, with BMI and body surface area (BSA) were calculated. Thyroid volume was examined by B-ultrasonography. Height volume index (HVI), weight and height volume index (WHVI), BMI volume index (BMIV) and BSA volume index (BSAV) were all applied to correct the thyroid volume. All students were followed up, one year later. Results: A total of 769 students with complete data on thyroid volume and physical growth were enrolled, including 378 boys (49.16%) and 391 girls (50.84%). Thyroid volume showed an increase with age, while growth of thyroid volume reduced with the increase of age (P<0.001). The thyroid volume showed a correlation with the changes of physical growth. The growth of height appeared as the dominant influencing factor for thyroid volume growth in those aged 8 and 10 years (P<0.05), while the growth of weight, BMI and BSA were all influencing factors for thyroid volume on students aged 9 years (P<0.05). Conclusions: Thyroid volume in school-aged children was a factor not only associated with age but also with physical growth which had not been considered in the currently used criteria. The inclusion of items as iodine intake, age, physical growth into the thyroid volume indexes seemed to be more reliable, in practice. For the assessment of goiter, HVI for students aged 8 and 10 years and BMIV for students aged 9 years might serve as better indicators.

Spatial-temporal analysis of enterovirus infection in Macao Special Administrative Region, China, 2011-2016 / 中华流行病学杂志

Objective: To understand the spatial-temporal distribution of enterovirus infection in Macao Special Administrative Region, China, from 2011 to 2016. Methods: The incidence data of enterovirus infections in child care settings and primary schools in Macao during this period, which were confirmed by the Health Bureau, were used for the spatial-temporal analysis. Bernoulli model was used as probability model. Software SPSS 20.0 was used for descriptive statistics of the study cases, and software SaTScan 9.4.4 was used for spatial and temporal scanning. Finally, software Google Earth was used for visualization of geographical information. Results: A total of 330 enterovirus infection events were reported in Macao from 2011 to 2016. The infection event number was highest in 2014 (101, 30.6%), the infections mainly occurred during May to June. A case clustering area with a radius of 0.7 km (high rates) was observed in northeast of Macao from 2011 to 2013 (log likelihood rate=13.4, P<0.001, RR=1.4). Conclusion: The annual prevention of enterovirus infection and related health education should be started in February and March in Macao, and the key area is the northeast of Macao island.

Spatial distribution of fluoride in drinking-water in Shandong Province based on a geographic information system / 中华地方病学杂志

Objective To detect the spatial distribution characteristics of water fluoride in Shandong Province.Methods The county-based study set Shandong Province as a research site.The county level fluoride database was matched with electronic maps to build geographic information system (GIS) spatial data platform.Global Moran's I and Local Moran's I index were calculated,respectively,and the cluster range of water fluoride distribution in Shandong Province was studied through SaTScan software.Results The water fluoride was normal (≤ 1.0 mg/L) in 54 counties in Shandong Province,mainly located in Weihai and Yantai in the eastern,Dongying in northern,and vast region in middle and southeastern of Shandong Province.Eighty-six counties were high water fluoride counties (＞ 1.0 mg/L),mainly distributed in the southwest,northwest and north-central of Shandong Province,showing a significant geographical feature.Global spatial autocorrelation analysis showed that the distribution of water fluoride content in Shandong Province showed significant positive spatial autocorrelation (Moran's I =0.44,Z =6.83,P ＜ 0.01).Local Moran's I analysis showed water fluoride in 13 counties had local spatial autocorrelation,being all high-high clusters.And these results were statistically significant (P ＜ 0.05).A cluster area was detected through SaTScan spatial analysis software,including 15 counties.The center was located in Dongming County of Heze City,with radius of 130.08 km.The results and the local spatial autocorrelation results were basically consistent.Conclusions There are apparent spatial autocorrelation and spatial cluster in water fluoridation in Shandong Province.Spatial autocorrelation and SaTScan software can be combined in exploring the spatial distribution of water fluoride.