Objective To analyze the drug resistance and its risk factors of pulmonary tuberculosis patients, so as to provide basis for the prevention and control of drug resistant tuberculosis. Methods Data of 1 201 hospitalized tuberculosis patients in designated hospitals and drug sensitivity of M.tuberculosis were collected. Descriptive epidemiological analysis was used to analyze the data, and univariate and multivariate Logistic regressions were used to analyze the factors influencing drug resistance of M.tuberculosis. ResultsThe average age of 1 201 patients with pulmonary tuberculosis was （40.2 ±18.7） years （range, 6-88 years）. Among them, 829 （69.03%） were male and 372 （30.97%） were female; 1 065 （88.68%） were newly treated and 136 （11.32%） were retreated. The total drug resistance rate of newly treated patients （27.89%） was lower than that of retreated patients （62.50%） （P < 0.01）. The drug resistance rate of any drug, multi drug resistance rate and extensive drug resistance rate were significantly different between newly treated and retreated patients （P < 0.05 or P < 0.01）. The risk factors of drug resistance in newly treated patients were anti tuberculosis treatment history （OR=1.777） and diabetes mellitus （OR=1.568）, and in retreated patients were treatment ≥ 2 times （OR=3.428）, living in villages and towns （OR=3.053） and age of 41-60 years （OR=2.866）. ConclusionThe drug resistance rate of pulmonary tuberculosis patients in this area is higher, and the drug resistance rate of retreated patients is higher than that of newly treated patients. The influencing factors of drug resistance of newly treated patients and retreated patients are different. Corresponding treatment and control measures should be taken according to different types of patients to avoid drug resistance.

Objective To investigate the influencing factors of allergic diseases in infants aged 0-24 months in Tianjin, and to provide scientific basis for disease prevention and control. Methods From November 2017 to June 2018, a stratified convenience sampling method was used to conduct a questionnaire survey among mothers of infants aged 0-24 months in Tianjin, including allergic diseases in infants and related influencing factors. Descriptive epidemiological analysis method was used to analyze, and univariate and multivariate analysis were used to analyze the influencing factors of infant allergic diseases. Results A total of 400 infants aged 0-24 months in Tianjin were investigated, 58.5% were boys, 32.5% were 7-12 months old, and 82.5% lived in the urban. Among them, 149 children with allergic diseases, the prevalence rate was 37.3%. Multivariate Logistic regression analysis showed that infants aged 0-6 months （OR=1.998） had a higher risk of allergic diseases; and those living in the urban （OR=0.517）, knowledge of exclusive breastfeeding for at least 4-6 months reduced children's allergic risk （OR=0.303） and pregnancy supplementation with probiotics （OR=0.511） had a lower risk of allergic diseases （P<0.05 or P<0.01）. Conclusion The incidence of allergic diseases in infants aged 0-24 months in Tianjin is high, and the risk can be reduced by living in the urban, breast feeding for at least 4-6 months and supplementation of probiotics during pregnancy. More attention should be paid to the risk of allergic diseases in infants aged 0-6 months.

Objective Constructing an optimal model for varicella prediction in Nanjing City to provide scientific guidance for the prevention and control of varicella. Methods Constructed Holt-Winters addition model, Holt-Winters product model and autoregressive integrated moving average （ARIMA） model based on the monthly varicella incidence rate in Nanjing from 2014 to 2018. By testing the parameters of the models and calculating the relative errors between predicted and actual values, selected the optimal model to predict varicella incidence in Nanjing in 2019. Results Based on Ljung-BOX test level, rejecting the Holt-Winters addition model and selecting the Holt-Winters product model and ARIMA model as the varicella prediction model. The bayesian information rules （BIC） of Holt-winters product model and ARIMA model was 1.24 and 1.81, respectively; the mean absolute percentage error （MAPE） was 14.24% and 21.86% respectively; the R² was 0.97 and 0.97, respectively; the average relative error between the predicted value and the actual value was 11.90% and 15.76%, respectively. Conclusion Holt winters product model is superior to ARIMA model in fitting and forecasting effect, and it is a high accuracy model for varicella prediction in the short term.

Objective To analyze the status and influencing factors of different frequency hearing loss among noise-exposed workers in an automobile manufacturing enterprise in Guangzhou. Methods Noise-exposed workers from an automobile manufacturer in Guangzhou who underwent occupational health examination in Guangzhou Occupational Disease Prevention and Treatment Hospital from January to December 2018 were selected as the study subjects. The subjects were examined by pure tone threshold test, noise exposure level test and questionnaire survey, then the cumulative noise exposure was calculated, and the correlation between each factor and the occurrence of different frequency hearing loss was analyzed by univariate and multivariate Logistic regressions. Results All 2 605 noise-exposed workers were male and Han nationality, 22 （20, 24） years old, working for 3 （1,4） years, and the noise exposure intensity was 83.50 （82.10, 86.10） dB（A）, cumulative noise exposure was 87.97 （85.11, 90.81） dB（A）·year.The detection rate of hearing loss was 34.40% （896/2 605）. There were no statistically significant difference in the detection rates of hearing loss, whisper frequency and high frequency hearing loss between left and right ears （P>0.05）.The detection rates of hearing loss in both left and right ears increased with the increase of frequency （trend χ²=1 111.38, 1 237.14, P<0.01）,and the highest detection rate was at 6.0 kHz in both left and right ears.Multivariate Logistic regression showed that no significant correlation between smoking, drinking and hearing loss at all frequencies （P>0.05）.With the increase of cumulative noise exposure（OR values of 0.5-6.0 kHz were 3.231, 4.151, 4.809, 3.282, 2.735, 2.069, respectively）or age（OR values of 0.5-6.0 kHz were 2.167, 2.323, 2.508, 1.776, 1.414, 1.276, respectively）, the detection rate of hearing loss of each frequency gradually increased （P<0.05）. Conclusion The hearing loss of noise-exposed workers in automobile manufacturing enterprises with different frequencies is more significant at 6.0 kHz, and there is a dose-response relationship between cumulative noise exposure, age and hearing loss at each frequency.

Objective To investigate the status and influencing factors of bone mass abnormality in community-dwelling elderly people in Kaifeng City, and put forward scientific suggestions for the prevention and treatment of bone mass abnormality related diseases in this area. Methods Questionnaire survey, physical examination and bone mineral density measurement were conducted on healthy people aged over 60 years old in a community in Kaifeng City from January to May, 2019. Descriptive epidemiological method was used for analysis, and multivariate Logistic regression analysis was used to analyze the influencing factors of bone mass abnormality. Results A total of 700 healthy people aged 60 to 90 years old in Kaifeng City were analyzed, including 285 males （40.7%） and 415 females （59.3%）. One hundred and six cases of bone mass abnormality were detected in men （37.2%, 106/285）, and 309 cases in women （74.5%, 309/415） ,respectively. Multivariate Logistic regression analysis showed that men who took calcium tablets （OR=0.135）, moderate-intensity exercise （OR=0.185）, adequate sleep duration and average （OR=0.205, 0.121） had lower risk of bone mass abnormality; Women with hypertension （OR=1.754） had higher risk of bone mass abnormality, and women who took calcium tablets （OR=0.187）, adequate sleep duration and average （OR=0.458, 0.417） had lower risk of bone mass abnormality. Conclusion The incidence of bone mass abnormality is relatively high in people aged over 60 years old in community of Kaifeng City, especially elderly women. The influencing factors of bone mass abnormality in community elderly of different genders are not completely the same, and more attention should be paid when preventing and treating osteoporosis-related diseases.

Objective To analyze the vaccination will and its influencing factors of pneumococcal polysaccharide vaccine in elderly diabetic patients. Methods The elderly patients with diabetes who received regular physical examination in a health service center of a hospital in Shanghai from April 2019 to April 2020 were investigated. The “PPV23 pneumonia vaccination willingness questionnaire” was designed to investigate the basic conditions of elderly patients and the PPV23 pneumonia vaccination willingness, and multivariate Logistic regression analysis was used to analyze the factors affecting the PPV23 pneumonia vaccination willingness of the elderly patient group. Results A total of 1 240 elderly patients were investigated, with an average age of （68.35±5.13） years, of which 546 （44.03%） were willing to receive PPV23 pneumonia vaccine. Multivariate analysis showed that the younger the age （OR=4.346）, the higher the family's highest education （high school or technical secondary school, OR=2.269; junior college and above, OR=2.173）, a history of chronic respiratory disease （OR=2.548）, the belief that pneumonia was severe disease （OR=1.756）, worried about owning pneumonia disease （OR=1.861）, knowing that PPV23 pneumonia vaccination could prevent pneumonia （OR=2.085）, family members suffered chronic respiratory disease （OR=4.166）, family members or friends recommended vaccination PPV23 pneumonia vaccine （OR=3.572）, doctors recommended vaccination PPV23 pneumonia vaccine（OR=2.604）, the more likely the elderly diabetic patients to be vaccinated with PPV23 pneumonia vaccine. Conclusion Elderly diabetic patients have low willingness to vaccinate PPV23 pneumonia vaccine. Ages, history of chronic respiratory diseases, knowledge of pneumonia and vaccines, and doctor's advice are related factors affect their willingness to vaccinate. It is recommended to strengthen the publicity and education on the preventive effect and safety of pneumonia vaccine to improve the awareness of PPV23 pneumonia vaccine in elderly diabetic patients.

Objective To investigate the association between dietary vitamin intake and carotid artery stenosis in patients with ischemic stroke. Methods Patients with ischemic stroke hospitalized in Jinling Hospital from January 2016 to December 2019 were included. Dietary vitamin intake was assessed with food questionnaire. Carotid artery stenosis was evaluated with computed tomography angiography （CTA）. Blood neutrophil count, lymphocyte count, serum homocysteine （Hcy）, C-reactive protein （CRP）, and hemoglobin A1c（HbA1c） were detected. Ordered Logistic regression analysis was used to evaluate the association between dietary vitamin intake and carotid artery stenosis. Results A total of 628 patients with ischemic stroke were enrolled, with an average age of （64.8±10.9） years, 390 （62.1%） were detected with carotid artery stenosis. Ordered Logistic regression showed that vitamin B₃ （OR=0.954, 95% CI： 0.913-0.997）, vitamin B₆ （OR=0.634, 95% CI： 0.407-0.989） and vitamin B₁₂ （OR=0.796, 95%CI： 0.663-0.956） were independent predicators of the degree of carotid artery stenosis. Conclusion Dietary vitamin intake in patients with ischemic stroke may influence the degree of carotid artery stenosis. Maintaining adequate intake of vitamin B₃, B₆ and B₁₂ may be beneficial for preventing development of atherosclerosis.

Objective To identify impact factors of dengue fever and provide evidence and support for developing control and prevention strategies. Methods A frequency-matching case-control study was adopted to conduct questionnaire survey and laboratory test on the subjects. Random forest model, single factor analysis and multivariate Logistic regression analysis were carried out to identify the impact factors of dengue fever. Results A total of 294 cases （158 males and 136 females） were included in the case group with an average age of （37.0±13.8） years, and 691 cases （329 males and 362 females） were included in the control group with an average age of （36.6±13.2） years. The first 20 variables selected by the random forest model were introduced into the multivariate Logistic regression model. Multivariate Logistic regression analysis showed that a total of seven factors were independent protecting factors including taking preventive measures outdoors （OR=0.29, 95% CI： 0.20-0.43）, knowing spreading vectors of dengue fever （OR=0.40, 95% CI： 0.25-0.64） and mosquitoes' habitats （OR=0.67, 95% CI： 0.50-0.89）, using air-conditioning in summer （OR=0.60, 95% CI： 0.38-0.90）, using screen windows and doors at home （OR=0.52, 95% CI： 0.34-0.79）, cleaning up the garbage in time （OR=0.43, 95%CI： 0.23-0.79） and working indoors with air-conditioning （OR=0.46, 95% CI： 0.30-0.72）. However, people whose family members （OR=6.94, 95% CI： 2.91-16.56） or friends or colleagues（OR=2.71, 95% CI： 1.56-4.72） suffered from dengue fever were at higher risk for dengue infection. Conclusion The infection of dengue fever is highly associated with individual recognition of the disease, mosquito preventive measures, household environment and working environment. It is essential to take preventive measures targeting these factors to decrease the risk of dengue infection.

Objective To analyze the management and its effectiveness in close contacts of COVID-19 in Guangzhou City. Methods General demographic information, relationship and contact situation with related cases, and medical observation outcome of close contacts were collected to compare the above characteristics of close contacts in 1^st（from January 21-30）, 2^nd （from January 31 to February 8）and 3^rd （from February 9 to March 2）period. Results A total of 2 312 close contacts were tracked. Male-to-female ratio was 1.15∶1, most of them were 20-59 years old, accounting for 73.53%. Isolation rate was 96.63%, close contact to case ratio was 8.59, positive rate of close contact was 5.49%, proportion of case was 35.28%. Median time of last contact to oncome, oncome to diagnosis were 2 d and 4 d, respectively. From 1^st to 3^rd period, isolation rate （ from 91.88% to 97.83%, P<0.01） and close contact to case ratio （ from 3.86 to 41.26, P<0.01） increased, positive rate of close contact （from 14.06% to 1.13%, P<0.01） decreased, proportion of case （ from 23.94% to 54.00%, P<0.01） increased, median time of oncome to diagnosis （ from 4 d to 0 d, P<0.01） decreased. Close contacts with social contact related （from 16.24% to 42.63%, P<0.01）, general or occasionally contact frequency （from 42.57% to 90.64%, P<0.01） increased. Compared with negative group, positive group had a shorter time of last contact to observe in whole period and 3^rd period （P<0.01）. Conclusion COVID-19 has been well controlled from community epidemic by sequential strengthen and effective management of close contacts in Guangzhou City. We suggest to establish a classification scheme for close contact management of different infection risk, so as to precise prevention and control.

Objective To analyze the epidemiological characteristics of COVID-19 of Guangzhou Baiyun International Airport and evaluate the epidemic prevention and control effect， so as to provide theoretical basis for further development of COVID-19 overseas entry prevention and control in Guangzhou Baiyun International Airport. Methods The data of COVID-19 published in Guangzhou City from March 15 to April 15， 2020 were collected， and the epidemic characteristics were analyzed by descriptive epidemiology method.Combined with a series of measures for epidemic prevention and control， the intervention effect was evaluated. Results By 24∶00 on April 15， 2020， a total of 142 cases had entered Guangzhou Baiyun International Airport， including 120 confirmed cases， 3 asymptomatic cases and 19 imported related cases. There were 122 cases （85.92%） aged 20-60 years old， 86 cases （60.56%） were male and 56 cases （39.44%） were female； 112 cases （78.87%）were Chinese nationality and 30 cases（21.13%） were foreign nationality； there were 70 cases （49.30%） from Euro?American countries； 46 cases （32.39%） were international students and 62 cases （43.66%） were in?service staff； 77 cases （54.23%） were screened at frontier ports. The epidemic curve peaked on March 21， and then fell down slowly. After the implementation of a series of prevention and control measures， all inbound flights were fully inspected， and there was no case of infection and death of quarantine personnel. Conclusion With the continuous aggravation of overseas epidemic situation， new situation of imported epidemic situation in Guangzhou has emerged. It is suggested that based on the preliminary prevention and control measures and deployment requirements， the prevention and control strategies and measures should be further consolidated in view of the new situation of epidemic prevention.

Objective To investigate the clinical and epidemiological characteristics of COVID-19 confirmed cases in Yunnan Province. Methods A retrospective study was used to analyze the general epidemiological data and clinical examination data of COVID-19 confirmed cases publicly released in Yunnan Province. Results There were 174 confirmed cases, aged 3-85 years old, with an average age of （41.7±18.1） years; 89 males （51.1%） and 85 females （48.9%）. All 14 prefectures and cities in the province had confirmed cases. After admission, the condition assessed was 21.3% for mild type, 68.8% for common type, 9.2% for severe type, and 0.7% for critically type; 98.9% were discharged from hospital and 1.1% died. Among the confirmed cases, 47.4% were from Hubei and 42.9% from Yunnan. 51.1% were from Wuhan to Yunnan, 11.5% had been to Wuhan, 11.5% had close contact with COVID-19 patients, and 24.7% had an unclear epidemiological history. In the first episode and clinical symptoms, fever, cough, sputum, and fatigue were the main manifestations. In laboratory tests, 95.5% of patients had normal or decreased white blood cells, 41.3% had a decrease in the count of lymphocyte, and 29.2% had a decrease in the percentage of lymphocytes; A small number of patients had elevated aspartate aminotransferase （AST） and alanine aminotransferase （ALT）. There was statistically significant difference in the proportion of fever in the first symptoms of mild/common type and severe/critical type （48.2% vs 78.6%, P < 0.05）. Conclusion Most patients with COVID-19 in Yunnan Province have a clear epidemiological history, and the population is generally susceptible, and there is no difference between genders. Most of the patients with clinical classification are common type, mainly manifested in fever, cough, sputum, fatigue, and good prognosis.