Since the 1990s, emerging infectious diseases have been found in the world. After SARS in 2003, there have been several domestic and imported emerging infectious diseases in China, indicating a not optimistic situation. The associated and driven factors of occurrence or spreading of emerging infectious diseases come from biological, natural and social fields. Therefore, the world health organization and the international community focus on the establishment of effective regional and international monitoring and response systems. Although the emerging infectious diseases response capacity in China has been systematically improved since the SARS epidemic in 2003, there still has deficiencies on mechanism and system. Considering the current emerging infectious diseases situation and challenge, the key area or pathogens and the tasks of capacity building on surveillance, early warning and response need to be clarified and strengthened in China.

Objective To analyze the pathogenic epidemiological characteristics of acute lower respiratory tract infection(ALRTI) in children in Gansu Province from 2012 to 2015. Methods The surveillance data of 458 children infected with ALRTI in 10 sentinel hospitals in Gansu province from 2012 to 2015 were collected, and infection status and epidemiological characteristics of each virus and bacteria were analyzed by descriptive study methods. Results The male to female ratio of the 458 children with ALRTI was 1.81:1, and the positive detection rate of the virus was 33.62%（95% CI：29.28%-37.97%), among which the positive detection rate of respiratory syncytial virus was the highest (12.23%).The positive detection rate of bacteria was 24.84%（95% CI：20.04%-29.65%),among which the positive detection rate of streptococcus pneumoniae was the highest (18.47%).There was significant no difference in the positive detection rate of virus and bacteria between children of different genders (P>0.05).There was significant no difference in the positive detection rate of virus among children of different age groups ( 2=5.980,P=0.050), but the positive detection rate of bacteria was different ( 2=12.078,P=0.002).Positive detection rates of virus infection and bacterial infection were different in distinct seasons (all P<0.05). By using logistics regression analysis, season, age and sentinel hospital were the influencing factors of ALRTI virus infection in children (all P<0.05), and sentinel hospital and years were the influencing factors of ALRTI bacterial infection in children (all P<0.05). Conclusion Respiratory syncytial virus, influenza virus and parainfluenza were the main causes of ALRTI virus infection in children aged 0-14 years in Gansu province, and the main bacterial infections were streptococcus pneumoniae and haemophilus influenzae, the number of virus infection was more than that of bacterial infection. Viral and bacterial infection had the same peak incidence.

Objective To provide reference for formulating scarlet fever prevention and control strategies by analyzing the epidemiological characteristics and predicting the incidence trend of scarlet fever. Methods Spearman correlation analysis, clustering analysis, seasonal index model and seasonal ARIMA model were used for analysis and prediction. Results The average annual incidence of scarlet fever in 2010-2018 was 1.37/100 000, and there was a positive correlation between annual incidence and year (rs=0.817,P=0.007). April-June and November-December were high incidence months. The clustering analysis was significant(F=4795.30，P<0.001), showing that the high-incidence areas are Shennongjia, Yichang, Enshi, Wuhan. Reported cases were concentrated in 1-14 years old, mainly for students, child care children and scattered children. The incidence rate of males was higher than that of females. The optimal model is ARIMA(0,1,1)(0,1,0)12. The prediction showed that the monthly incidence characteristics of 2019 were consistent with previous years, and the annual incidence rate was 10.22/100 000(95% CI:2.33/100 000-30.43/100 000), which was higher than the incidence of 2018. Conclusions The incidence of scarlet fever in Hubei Province is generally on the rise from 2010 to 2018. The incidence is bimodal. Students are the main disease group. The incidence rate of males is higher. The incidence is mainly concentrated in the mountainous areas of southwest and capital cities. The ARIMA model has a good applicability in the prediction of scarlet fever. The incidence level will continue to rise in 2019, and it is necessary to strengthen monitoring and control measures with reference to epidemiological characteristics.

Objective To analyze the epidemic trend of hepatitis B virus (HBV) in 18 minority nationalities in Yunnan Province from 2009 to 2018, so as to explore the ethnic differences in the incidence of HBV in Yunnan Province. Methods Based on the reported incidence data of hepatitis B in China's disease prevention and control information system from 2009 to 2018, descriptive epidemiology method was used to describe and analyze the incidence of hepatitis B in different ethnic groups, and K-means clustering method was used to explore and analyze the annual average incidence of hepatitis B in different ethnic groups. Results From 2009 to 2018, the average incidence of hepatitis B in Yunnan Province was 44.26/100 000, which was much lower than the overall level of China every year; the average incidence of hepatitis B in ethnic groups was 41.27/100 000, slightly lower than the overall level of Yunnan every year. The prevalence of hepatitis B was different in different ethnic groups. The average incidence of Wa was significantly higher than others (95.26/100 000), and Jingpo was the lowest (22.51/100 000). According to the incidence of hepatitis B, different ethnic groups were divided into three categories: high incidence ethnic group, middle incidence ethnic group and low incidence ethnic group. Conclusion There are ethnic differences in the incidence of hepatitis B in Yunnan Province. The incidence of hepatitis B in some ethnic groups is higher than that in the whole country all the year round, which is the key population in the prevention and control of hepatitis B.

Objective To analyze the genetic characteristics of the hemagglutinin （HA) and neuraminidase （NA) genes of influenza B viruses isolated in Yancheng City from 2015 to 2017. Methods The throat swab specimens of influenza-like illness( ILI) from sentinel surveillance hospital and outbreak sites were collected and sent to Yancheng CDC for virus nucleic acids and virus isolation testing. After validation with serological tests, eighteen strains of influenza B virus isolates were selected to amplify their HA1 and NA genes through RT-PCR assay. Their molecular characteristics of the obtained viral HA1 and NA gene sequences were analyzed using bioinformation software from three aspects, including nucleic acid level, amino acid level and molecular evolution level. Results Basically, the clustering relationships and the branche patterns between HA1 and NA genes from the 18 Yancheng influenza B virus strains were similar. The Yamagata lineage strains in 2015 were distributed in the Yamagata Clade 3 branch, belonging to Phuket/3073 strains. The Victoria lineage strains in 2016-2017 were distributed in the Victoria Clade 1A branch, belonging to Brisbane/60 strains. D196N substitution was detected on HA1 protein in all of Yamagata lineage strains at 190-helix epitope; Amino acid substitutions of victoria lineage strains involved two antigenic epitopes, 117 and 129 sites of 120-loop epitope and 197 and 199 sites of 190-helix epitope. No Intra-lineage or inter-lineage rearrangements occurred in Yancheng strains. Eighteen influenza B strains had no mutations in catalytic residues and drug resistant sites of NA genes. Conclusion The Yamagata strains well matched with vaccine strain B/Phuket/3073/2013. The HA1 and NA genes of victoria lineage strains circulated in Yancheng City during 2016 to 2017 are changing gradually. The accumulation of these mutations will result in antigenic drift of victoria lineage strains and increase the mismatch of the IFV field stains with the available vaccine strains, which may reduce the protective effect of flu vaccine.

Objective To analyze the differences in the expression levels of the lncRNA MALAT1, NEAT, NEAT2 in peripheral blood mononuclear cell (PBMC) from tuberculosis patients and healthy controls. Methods We detected the lncRNA expression levels in PBMC from 79 tuberculosis patients and 82 healthy controls by quantitative reverse transcription polymerase chain reaction, and analyzed the correlation between lncRNA expression levels and some clinical features and laboratory indicators in tuberculosis patients. Results The expression levels of MALAT1, NEAT1 in PBMC of tuberculosis patients were significantly higher than healthy controls (Z=-4.386, P<0.001; Z=-10.175, P<0.001). There was no significant difference in the expression of NEAT2 between tuberculosis patients and healthy controls (Z=-0.203，P=0.839). The correlation results of lncRNA levels and some clinical features, laboratory indicators in tuberculosis patients suggested that the NEAT2 level in PBMC of newly treated tuberculosis patients was higher than recurrent tuberculosis patients, while the NEAT2 level in PBMC of sputum smear positive tuberculosis patients was lower than that of sputum smear negative tuberculosis patients (all P<0.05). There was a negative correlation between MALAT1 level and erythrocyte sedimentation rate (rs=-0.256, P=0.034). Conclusion MALAT1 and NEAT1 are abnormally expressed in PBMC of tuberculosis patients, and may be involved in the pathogenesis of pulmonary tuberculosis.

Objective To understand the main serotypes, antibiotic resistance profiles and molecular typing characteristics of Listeria monocytogenes（LM) isolated from foods in Shandong Province from 2013 to 2016. Methods The antibiotic sensitivity of LM was tested by broth microdilution method. The serotypes were determined by slide agglutination and PCR, and the molecular typing was carried out by pulsed field gel electrophoresis (PFGE) and multilocus sequence typing(MLST) . Results Most of 191 LM strains were sensitive to the eight antibiotics tested. Tetracycline resistance was most prevalent (15/191, 7.85%). There was no significant difference in the 8 antibiotic resistance monitored for 4 years (P=1.000). The serotype 1/2a, 1/2b and 1/2c accounted for 38.82% (66/170), 18.82% (32/170), and 42.36% (72/170), respectively. The patterns of SDSRZXDZ016, S2014L031 and SDSRZX030, totally accounted for 33.78%, were the dominant types. The main ST types were ST9, ST8 and ST121, which accounted for 81.18% (69/85). The clinical common types, ST3, ST7 and ST87 accounted for 8.23% (7/85), mainwhile new ST type was not found. Conclusion The LM strains isolated in Shandong Province from 2013 to 2016 were sensitive to most antibiotics, but some strains were resistant to tetracycline and erythromycin. The dominant serotypes were 1/2c and 1/2a. Serotype 4b, prone to outbreaks of listeriosis, was not found. The main PFGE types were SDSRZXDZ016, S2014L031 and SDSRZX030, which were continuously found from 2013 to 2016. The main ST types were ST8, ST9 and ST121. The clinical types, ST3, ST7 and ST87 were isolated from food and should be paid seriously attention to.

Objective The aim of the present study was to investigate the relationship between the intake of salt and salted food and the infection of Helicobacter pylori (Hp) among 40-69 years old local residents in a county with high gastric cancer risk in Anhui province. Methods From July 2015 to August 2018, we conducted a questionnaire and a serological test for Hp among 40-69 years old local residents in Lujiang county, Anhui province. The questionnaire focused on the consumptions of salt and salted food. The relationship between Hp infection and risk factors was analyzed by gender. Univariate and multivariate logistic regression analysis were used to analyze the relevant influencing factors. Results The Hp infection rate of total local residents was 50.07%. Among male subjects, age, body mass index(BMI), marital status, educational level, job, labor intensity and income had no link to Hp infection (all P>0.05). But among female subjects, BMI was associated with Hp infection ( 2=13.454,P=0.001). Besides, alcohol consumption was a risk factor for Hp infection in male subjects(OR=1.789，95% CI:1.188-2.694，P=0.003). But, high intake of salt and salted food had no effect on Hp infection after adjustment for alcohol consumption variable in men using multivariate analysis (all P>0.05). After adjusted for BMI variable among female individuals, high salt intake (≥9 g/day) (OR=1.462，95% CI:1.060-2.015，P=0.021) and the high salted food intake (≥1 times /day) were risk factors for Hp infection in women(OR=1.560，95% CI:1.021-2.383，P=0.040). Conclusions In one county with high gastric cancer risk in Anhui province, high salt intake (≥9 g/day) and high salted food intake (≥1 times/day) are risk factors for Hp infection among 40-69 years old female local residents.

Objective To explore the associations of body mass index (BMI), waist circumference (WC), waist height ratio (WHtR) and the prevalence of hypertension in elderly residents over 60 years in Baodi district, Tianjin. Methods Residents over 60 who underwent medical examinations in the Koudong Health Center, Baodi district, Tianjin, were all invited to participate in the study from April to May, 2018. Participants were asked to fill out structured questionnaires and undergo physical examinations. Stratified analysis and logistic regression analysis were applied to examine joint effects and interactions of BMI and WC (or WHtR) on the risk of hypertension. Results A total of 1 417 residents (83.75%) out of 1 692 residents participated in the study. The prevalence of hypertension in the participants was 46.36%. 66.50% of the participants were BMI overweight or obese. Participants with central obesity accounted for 74.66% (measured by the WC) and 75.38% (by the WHtR). Compared to the normal weight measured by the BMI or the WC, BMI overweight (OR=1.65, 95%CI: 1.19-2.30) or obesity (OR=3.41, 95%CI: 2.23-5.20) and WC central obesity (OR: 1.49, 95%CI: 1.00-2.23) were associated with increased risk of hypertension. The joint effects of BMI and WC (OR=2.49, 95%CI: 1.78-3.46), or BMI and WHtR (WHtR overweight: OR=2.05, 95%CI: 1.41-2.99; WHtR obesity: OR=2.37, 95%CI: 1.50-3.76) were greater than the single effect of the latter (WC overweight/obesity: OR=1.39, 95%CI: 0.90-2.15; WHtR overweight: OR=1.02, 95%CI: 0.62-1.66; WHtR obesity: OR=1.44, 95%CI：0.55-3.81). Conclusions Of the three indices, BMI is strongly correlated with the risk of hypertension. BMI overweight or obesity has enhanced the association of WC or WHtR and the risk of hypertension, suggesting that weight control in the normal range, especially measured by the BMI index, may prevent and control hypertension.

Objective To investigate the incidence of hypertension among Chinese middle-aged and elderly people, and to explore the association of sleep duration and sleep quality with the incidence of hypertension. Methods Our data were collected from the 2011 and 2015 China health and retirement longitudinal study(CHARLS),a total of 6 047 middle-aged and elderly individuals aged 45 years and over were included in this study, sleep duration were measured as self-reported average sleep time in the past month. Sleep quality was evaluated using the self-made questionnaire. The association of sleep duration and sleep quality with the incidence of hypertension was analyzed using multivariate logistic regression analysis. Results After four years of follow-up,1 151 peoples developed hypertension, and the cumulative incidence rate was 19.03%. Logistic regression analysis showed that abnormal sleep time or poor sleep quality had no effect on the incidence of hypertension. The results remained unchanged in the subgroup analysis of sex and age. Further investigation of the association of different combinations of sleep duration and quality in relation to hypertension indicated that the combined effect of sleep time and sleep quality on hypertension was not statistically significant (all P>0.05). Conclusion There is no sufficient evidence supporting correlation between sleep time and sleep quality with the incidence of hypertension in the middle-aged and the elderly in China, and age and sex had no effect on the correlation.