[Practice and thinking of acute respiratory infection surveillance for the response of emerging respiratory diseases in Shanghai].

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.

[Epidemiological characteristics and measures of prevention and control of imported COVID-19 cases in early phase in Shanghai].

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.

[Analysis of adenovirus infection in acute respiratory tract infection cases in Shanghai from 2015 to 2019].

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 (χ(2)= 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 (χ(2)=16.94, P=0.001), and the positive rate decreased with age (χ(2)=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 (χ(2)=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.