Objective To compare the detection situation of influenza-like illnesses with different symptoms and analyze the impact on the influenza surveillance by adopting different case definitions of influenza-like illness.Methods Data was collected from 2 national influenza surveillance sentinel hospitals in Shanghai,2015.We compared the positive rate of influenza virus among patients with different symptoms (with cough and sore throat,with cough only and with sore throat only),and utilized Logistic regression model to analyze the influencing factors of the detection rate of influenza virus.Results Among 2 010 influenza-like illnesses,1 105 patients were with cough and sore throat,270 patients were with cough,635 patients were with sore throat,and the positive rate of influenza was 36.2％,39.3％ and 15.9％ respectively.The patients with cough and sore throat or with cough only had a higher positive rate of influenza than patients with sore throat (all P ＜ 0.05).For patients with specimens collected within 3 days,patients with cough and sore throat,or with cough only had a higher positive rate than patients with sore throat only (all P ＜ 0.05).Logistic regression results showed that fever (body temperature≥39 ℃) (OR =1.719,95％ CI:1.389-2.127) and cough (OR =3.046,95％ CI:2.377-3.905) were associated with the detection of influenza virus.Conclusions We suggested that we can adopt the case definition of influenza-like illness'fever (body temperature ≥38 C) and cough'in the influenza surveillance system.

Objective:To study the epidemiological characteristics and mixed infection of adenovirus in acute respiratory tract infections in Shanghai from 2015 to 2019, and to provide scientific basis for the prevention and control of adenovirus.Methods:Acute respiratory tract infections were collected from 3 hospitals in Shanghai from 2015 to 2019. Relevant information was registered and respiratory specimens were sampled for detection of respiratory pathogens by multiplex PCR.Results:A total of 1 543 cases of acute respiratory tract infection were included. The positive rate of adenovirus was 2.92%(45/1 543), the positive rates of influenza like illness (ILI) and severe acute respiratory illness (SARI) were 2.74%(29/1 058) and 3.30%(16/485), respectively. The positive rate of ILI during January-May 2019 was 5.43%(7/129), higher than that in the same period of 2015- 2018 (0.52%-4.48%) (Fisher’s exact test value=8.92, P=0.036). The incidence of adenovirus-positive cases was mainly distributed in the first and second quarters, accounting for 62.22% (28/45). The difference of the incidence of adenovirus-positive cases in each quarter was significant ( χ2= 12.52, P=0.006). The positive rate in the second quarter was highest (6.03%), which was higher than that in other quarters (1.89%-2.93%). There were significant differences among different age groups ( χ2=16.94, P=0.001), and the positive rate decreased with age ( χ2=10.16, P=0.001). The positive rate of 13-19 years old group (9.43%) was higher than that of other age groups (1.48%-4.81%). The positive rate of student group (12.07%) was higher than that of other occupations (2.61%). The difference was systematic ( χ2=11.53, P=0.001). Mixed infection accounted for 31.11% (14/45) of 45 adenovirus positive cases. The mixed infection rates of ILI and SARI were 34.48% (10/29) and 25.00% (4/16), respectively. Among 14 cases of mixed infection, the main mixed infection pathogens of adenovirus were influenza A virus and coronavirus. Conclusion:Adenovirus surveillance should be further strengthened in adolescents with a focus on students and other key groups in the second quarter.

Shanghai Municipal Center for Disease Control and Prevention has implemented an active comprehensive surveillance project of acute respiratory infections in adults in Shanghai, including influenza like illness (ILI) and severe acute respiratory infection (SARI). By testing and identifying a variety of respiratory pathogens, it was found that influenza viruses were the main pathogens in 172 ILI cases in 2019. The positive rates of influenza A (H1N1) pdm09 virus, influenza A (H3N2) virus and influenza B virus Victoria lineage were 30.81%, 14.53% and 30.55%, respectively. The positive detection of influenza A (H1N1) pdm09 virus peaked in the first quarter. The positive rate of enterovirus/human rhinovirus was 6.40%, with a positive detection peak in the third quarter, while the positive rate of adenovirus was 4.65% with a positive detection peak in the second quarter of the year. Two human coronavirus (HCoV)-OC43 positive samples, 1 HCoV-HKU1 positive sample and 1 HCoV-NL63 positive sample were detected, respectively, and no HCoV-229E positive sample was detected. The detection rate of Staphylococcus aureus was 17.44%, and the detection rate of Klebsiellapneumoniae was 9.88%. Influenza viruses were also the main pathogens in 1 447 SARI cases. The positive rates of influenza A (H1N1) pdm09 virus, influenza A (H3N2) virus and influenza B virus Victoria lineage were 5.46%, 1.73% and 0.30%, respectively. The positive detection of influenza A (H1N1) pdm09 virus (17.50%) peaked in the first quarter. The total positive detection rate of enterovirus/human rhinovirus was 2.97%, the positive detection peaked in the first quarter. The positive rate of Mycoplasma pneumoniae was 3.25% and the positive rate of Legionella was 1.04%. 5 HCoV-229E positive samples, 10 HCoV-OC43 positive samples, 7 HCoV-HKU1 positive samples and 6 HCoV-NL63 positive samples were detected. Eight strains of Staphylococcus aureus, 4 strains of Pseudomonas aeruginosa and 3 strains of Klebsiella pneumoniae were detected after cultures. By implementing the active surveillance, we not only detected a case of human infection with avian influenza A(H7N9) virus in time, but also preliminary understood the pathogenic spectrum characteristics and seasonality of ILI and SARI in Shanghai. In recent years, the surveillance methods have been continuously improved and the number of sentinel hospitals has increased gradually. In particular, for the response to COVID-19, the Surveillance Information Reporting System of Acute Respiratory Infection based on HIS system has been promoted to cover the whole city, which might lay a foundation for the active surveillance and early warning of emerging infectious diseases in the future.

Objective:To analyze the epidemiological characteristics of imported COVID-19 cases in early phase in Shanghai, introduce measures and provide reference for prevention and control of imported COVID-19 cases.Methods:Data of imported COVID-19 cases in Shanghai reported as of 30 March, 2020 were obtained from National Notifiable Disease Report System of China CDC and field epidemiological investigation reports by CDCs in Shanghai. The information about measures of prevention and control was collected from official websites and platforms of the governments. Data cleaning and statistical analysis were performed with softwares of EpiData 3.1, Excel 2019 and SAS 9.4.Results:A total of 171 imported COVID-19 cases had been reported as of 30 March, 2020 in Shanghai, including 170 confirmed cases and 1 asymptomatic infection case. Among them, cases of Chinese nationality accounted for 71.3% (122/171) and cases of foreign nationality accounted for 28.7% (49/171). The median age of the cases was 23 years ( P 25, P 75: 18, 35 years), and the male to female ratio of the cases was 1.3∶1. Students accounted for 56.6% (97/171). About 45.6% (78/171) of the cases fell ill before arriving in Shanghai. The cases with mild or common clinical manifestation accounted for 96.5% (165/171) and no significant difference in clinical type was observed between overseas Chinese cases and foreign cases. The epidemic curve by diagnosis date reached peak on March 24, and the number of the cases gradually declined due to the closed-loop management process of joint port prevention and control mechanism. The 171 imported COVID-19 cases were mainly from 24 countries and regions, including the United Kingdom (64 cases, 37.3%), the United States (32 cases, 18.6%), France (19 cases, 11.0%) and Italy (16 cases, 9.4%). About 40.4% of the cases (69/171) planned to continue travelling to 21 other provinces and municipalities in China. Customs quarantine and community observation/detection points identified 43.9% (75/171) cases and 31.0% (53/171) cases, respectively. Conclusions:The imported COVID-19 cases in early phase in Shanghai were mainly young population and students accounted for high proportion. The imported risk of COVID-19 was consistent with the severity of the epidemic in foreign countries. The closed-loop management model of the joint port prevention and control mechanism plays an important role in the identification and management of the imported COVID-19 cases.

Objective:To understand the epidemiological and pathogenic characteristics of Legionella in artificial water environment of public places in Shanghai from 2011 to 2018, and to provide scientific basis for the prevention and control of Legionellosis.Methods:A total of 4 817 samples of artificial water environment were collected from 31 public places in Huangpu, Jing′an, Xuhui and Songjiang districts of Shanghai from 2011 to 2108. Epidemiological characteristics of the collected years and months, regional and site types, and sample types were analyzed. After treatment, culture and isolation of the collected water samples, the positive samples were analyzed for Legionella typing characteristics.Results:The positive rate of Legionella pneumophila was 21.57% (1 039/4 817), of which 96.25% (1 000/1 039) was single type, 84.31% (876/1 039) was Legionella pneumophila type 1, followed by Legionella pneumophila type 7 and 6, which accounted for 4.72% (49/1 039) and 3.75% (39/1 039), respectively, and 29 (29/1 039) were multi-type positive. Further typing. From May to October, the highest positive rates were found in July and August, 27.61%(222/804)and 28.61% (230/804)respectively. There were significant differences between different months ( P<0.001); the highest positive rates were found in central air-conditioning cooling water and chilled water (32.40%) and there were significant differences among different water samples ( P<0.001). Legionella pneumophila type 1, type 7 and type 6 were the main diversity distribution characteristics in artificial water environment of different regions, different time, different places and different types of public places. Legionella pneumophila type 1 accounted for the highest proportion, and the proportion of positive samples under different epidemiological characteristics was more than 71.64%. Conclusion:There is relatively serious pollution of Legionella pneumophila type 1 in the artificial water environment of public places in Shanghai. It is necessary to strengthen the disinfection of cooling water/freezing water of central air conditioning in public places in July and August every year.

Objective:To understand the epidemiological and pathogenic characteristics of Legionella in artificial water environment of public places in Shanghai from 2011 to 2018, and to provide scientific basis for the prevention and control of Legionellosis.Methods:A total of 4 817 samples of artificial water environment were collected from 31 public places in Huangpu, Jing′an, Xuhui and Songjiang districts of Shanghai from 2011 to 2108. Epidemiological characteristics of the collected years and months, regional and site types, and sample types were analyzed. After treatment, culture and isolation of the collected water samples, the positive samples were analyzed for Legionella typing characteristics.Results:The positive rate of Legionella pneumophila was 21.57% (1 039/4 817), of which 96.25% (1 000/1 039) was single type, 84.31% (876/1 039) was Legionella pneumophila type 1, followed by Legionella pneumophila type 7 and 6, which accounted for 4.72% (49/1 039) and 3.75% (39/1 039), respectively, and 29 (29/1 039) were multi-type positive. Further typing. From May to October, the highest positive rates were found in July and August, 27.61%(222/804)and 28.61% (230/804)respectively. There were significant differences between different months ( P<0.001); the highest positive rates were found in central air-conditioning cooling water and chilled water (32.40%) and there were significant differences among different water samples ( P<0.001). Legionella pneumophila type 1, type 7 and type 6 were the main diversity distribution characteristics in artificial water environment of different regions, different time, different places and different types of public places. Legionella pneumophila type 1 accounted for the highest proportion, and the proportion of positive samples under different epidemiological characteristics was more than 71.64%. Conclusion:There is relatively serious pollution of Legionella pneumophila type 1 in the artificial water environment of public places in Shanghai. It is necessary to strengthen the disinfection of cooling water/freezing water of central air conditioning in public places in July and August every year.

Objective:To analyze the features of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) co-infected with other common respiratory pathogens among coronavirus disease 2019 (COVID-19) patients in Shanghai City, and to provide a reference for scientific prevention and control of COVID-19 and other respiratory infectious diseases.Methods:Descriptive epidemiological approaches were used to analyze the data of COVID-19 reported cases in Shanghai City from January 2020 to February 2021 in the information system of Chinese Disease Prevention and Control. Clinical data of the participants were collected, and their SARS-CoV-2 nucleic acid-positive respiratory specimens were collected at the time of illness onset or admission. Multiplex reverse transcription-polymerase chain reaction (RT-PCR) was performed to detect the 22 respiratory pathogens. Independent-samples t test was used for statistical analysis. Results:Of the 272 patients with COVID-19, 15(5.5%) had co-infection of SARS-CoV-2 with other respiratory pathogens, all of which were double infection. There were three cases infected with enterovirus/rhinovirus, two of each with adenovirus, human metapneumovirus and coronavirus NL63/HKU1, and one of each with coronavirus 229E, influenza A virus H1N1, parainfluenza virus 1 and respiratory syncytial virus B. Two cases infected with Mycoplasma pneumoniae. Among the 272 COVID-19 patients, 212(77.9%) had fever, 117(43.0%) had cough, 46(16.9%) had fatigue, and 35(12.9%) had sore throat. The white blood cell count of co-infection cases was higher than that of non-co-infection cases ((6.8±1.7)×10 9/L vs (5.3±1.6)×10 9/L), and the difference was statistically significant ( t=3.09, P=0.008). Conclusions:There is a certain proportion of co-infection of SARS-CoV-2 with other respiratory pathogens among the COVID-19 cases in Shanghai City, mainly viral pathogens, especially enterovirus/rhinovirus. A rational combination of drugs was recommended to improve the cure rate. Surveillance of acute respiratory infection should be further strengthened as well.

Objective:To analyze the changes in the epidemiological characteristics of scarlet fever cases in Shanghai City before and after the outbreak of coronavirus disease 2019 (COVID-19), and to provide a reference for scientific prevention and control of scarlet fever.Methods:The information of scarlet fever reported cases in Shanghai City from January 2016 to June 2021 in the information system of Chinese Disease Prevention and Control was collected, and the differences in time trend, regional distribution, age and gender distribution of cases before and after the outbreak of COVID-19 in Shanghai City were analyzed by descriptive epidemiologic method.Results:The incidence rate of scarlet fever reported in 2016-2019 was (0.22-4.02)/100 000 in each month, with a median of 1.13/100 000. During January 2020 (the outbreak began in Shanghai City) and June 2021, the incidence rate of scarlet fever was (0.01-1.64)/100 000, with a median of 0.14/100 000, which was 12.39% of that before the outbreak of COVID-19. During February and June 2020, the monthly reported incidence rate of scarlet fever was (0.18-0.58)/100 000, showing an upward trend compared with the same period in 2020 ((0.01-0.05)/100 000). From 2016 to 2019, the annual reported incidence rate of each district was (0.55-65.48)/100 000, with a median of 9.57/100 000; while in 2020, the annual reported incidence rate of each district was (0.29-9.85)/100 000, with a median of 2.18/100 000, which was 22.78% of that before the outbreak of COVID-19. The incidence of scarlet fever dropped significantly. The incidence rate in Minhang District was still the highest. The cases were mainly four to eight years old, and there was no substantial difference of the proportions before and after COVID-19 pandemic, with the incidence rate of six years old group the highest. The proportion of male was more than female in reported case, while the male ratio in reported cases was not significantly different before and after COVID-19 pandemic.Conclusions:The incidence rate of scarlet fever in Shanghai City has dropped sharply after COVID-19 pandemic. The main epidemiological characteristics of the regional and population distribution of cases remain unchanged.

Objective: To analyze the etiologic and epidemiological characteristics of adult acute respiratory infections in Shanghai during 2015-2017. Methods: Data was collected from outpatients with acute respiratory infections who visited the Fever Clinics in three hospitals of different levels in three administrative regions of Shanghai, from 2015 to 2017. Basic information and nasopharyngeal swabs were collected from cases in line with the inclusion criteria. Multiplex RT-PCR and bacterial cultures were performed to detect the respiratory pathogens. Results: A total of 806 individuals were enrolled from 2015 to 2017. Respiratory pathogens were identified in 73.45% (592/806) of the cases, with the virus detection rate as 66.75% (538/806). It was found that the major respiratory pathogens for virus detection were influenza A in 326 (40.45%), influenza B in 116 (14.39%), rhinovirus/enterovirus in 39 (4.84%) of the cases. The overall detection rate of bacteria was 16.13% (130/806), including Klebsiella pneumoniae in 90 (11.17%) cases, Staphylococcus Aureus in 46 (5.71%) cases. Other kind of bacteria were not detected in our study. The detection rates on Mycoplasma pneumoniae was 5.33% (43/806) and on Chlamydia pneumonia was 0.37% (3/806). Co-infection with multiple pathogens was detected in 18.61% (150/806) of the cases, including 135 with double infection (accounting for 90.00%), 14 with triple infection and 1 with quadruple infection (accounted for 9.33% and 0.67%, respectively). Among the 150 cases with co-infections, the main identified pathogens were influenza A, Klebsiella pneumoniae, Staphylococcus aureus, and Mycoplasma pneumoniae. Pathogens of acute respiratory infections that identified among the outpatients from the Fever Clinics at different time, region or population, the characteristics were different (P<0.001). Conclusions In 2015-2017, outpatients with acute respiratory infections in Shanghai were mainly caused by influenza virus or other viruses, however dynamically with its composition, time, region and characteristics of the population. It is necessary to strengthen and combine related medical and preventive services and to develop the appropriate strategies regarding clinical diagnosis and treatment.

Objective: To understand the epidemiological and pathogenic characteristics of hospitalized severe acute respiratory infections (SARI) in Shanghai, China. Methods: From 2015 to 2017, one Tertiary hospital and one Secondary hospital were chosen as the surveillance sites. Two respiratory tract specimens per case were collected from SARI cases aged 15 years and older. One specimen was tested for 22 respiratory pathogens by RT-PCR, and the other specimen was cultured for 6 respiratory bacteria. Results: A total of 287 SARI cases were enrolled for sampling and lab testing. 70.73% of the cases were aged 60 years and older, with 41.46% (119/287) were positive for at least one pathogen. Influenza virus was the predominant pathogen, accounting for 17.77% (51/287) of all SARI cases. Human rhinovirus/Enterovirus and Coronavirus were both accounting for 7.32% (21/287), followed by Mycoplasma pneumoniae (5.57%, 16/287). The positive rates of parainfluenza virus, bocavirus, adenovirus, respiratory syncytial virus and human metapneumo virus were all less than 5%. Bacterial strains were identified in seven SARI cases, including Klebsiella pneumoniae (3 strains), Staphylococcus aureus (2 strains), Streptococcus pneumoniae (1 strain) and Pseudomonas aeruginosa (1 strain). Two or Three pathogens were co-detected from 40 cases, accounting for 33.61% of 119 positive cases. The most common co-detected pathogens were influenza virus and Mycoplasma pneumoniae (10 cases). Influenza cases peaked in winter-spring and summer. Mycoplasma pneumoniae peaked in winter-spring season and overlapped with influenza. The positive rates of pathogens were not significantly different between different age groups. Conclusions Various respiratory pathogens can be detected from SARI cases aged 15 years and older. Influenza virus was the predominant pathogen and the co-detection of influenza virus with Mycoplasma pneumoniae the most common one.