ObjectiveTo analyze the epidemiological characteristics and influencing factors of clustered influenza-like illness (ILI) outbreaks in Yangpu District, Shanghai from 2012 to 2022, and to provide a scientific basis for formulating specific prevention and control measures of influenza in this district. MethodsData on clustered ILI outbreaks from 2012 to 2022 were collected, and the epidemiological pattern of the cluster outbreaks of influenza and its influencing factors of prevalence and duration were explored using statistical methods such as descriptive epidemiology, χ² test and logistic regression analysis. ResultsA total of 60 clustered ILI outbreaks were reported in Yangpu District, Shanghai from 2012 to 2022, with a cumulative number of 543 cases and an annual average incidence rate of 16.96%. The male-to-female ratio was1.06∶1. The largest number of ILI were reported in 2019, mainly from November to January of the next year, with December being the peak of outbreaks. The Streets of Changhai Rd. in Yangpu District had the largest number of reported outbreaks, accounting for 30.00% of the total outbreaks. Influenza cluster outbreaks occurred in schools, with the majority of outbreaks and cases reported in primary schools (accounting for 65.00% and 62.06% of the total, respectively). The outbreaks were mainly caused by influenza B virus, accounting for 50% of the total number of outbreaks. The prevalence rate of influenza cluster outbreaks varied among different schools in terms of their affiliated streets, school attributes and school types, with those in Kongjiang Rd. Subdistrict, private schools, and childcare institutions being relatively high. The duration of outbreaks reported for >2 days was longer than those reported for ≤2 days (OR=8.604, 95%CI: 1.509–49.067). ConclusionThe ILI outbreaks in Yangpu District present a seasonal pattern, with primary schools and Changhai Rd. Street as the targeted places for implementing prevention and control measures. Timely detection and reporting and active disposal can prevent a further spread of the outbreaks.

ObjectiveTo analyze the evolutionary characteristics and genetic variations of the HA (hemagglutinin) and NA (neuraminidase) genes of influenza A(H1N1) viruses in Shanghai during 2024, to investigate their transmission patterns, and to evaluate their potential impact on vaccine effectiveness. MethodsFrom January to October 2024, throat swab specimens were collected from influenza like illness (ILI) patients at 4 hospitals in Shanghai. Real-time fluorescence ploymerase chain reaction (RT-PCR) was used for virus detection and isolation of H1N1 influenza viruses. Forty influenza A(H1N1) virus strains were sequenced using Illumina NovaSeq 6000 platform, followed by phylogenetic analyses, genetic distance analysis, and amino acid variation analyses of HA and NA genes. ResultsPhylogenetic tree of the HA and NA genes revealed that the 40 influenza A(H1N1) virus strains circulating in Shanghai in 2024 exhibited no significant geographic clustering, with a broad origin of strains and complex transmission chains. Genetic distance analyses demonstrated that the average intra-group genetic distances of HA and NA genes among the Shanghai strains were 0.005 1±0.000 6 and 0.004 6±0.000 6, respectively, which were comparable to or higher than those observed in global surveillance strains. Both HA and NA genes displayed frequent mutations. Compared to the 2023‒2024 and 2024‒2025 Northern Hemisphere A(H1N1) vaccine strains (WHO-recommended), the HA proteins of 40 Shanghai strains exhibited amino acid substitutions at positions 120, 137, 142, 169, 216, 223, 260, 277, 356 and 451, with critical mutations at positions 137 and 142 located within the Ca2 antigenic determinant. Furthermore, mutations in the NA protein were observed at positions 13, 50, 200, 257, 264, 339 and 382. ConclusionThe genetic background of the 2024 Shanghai influenza A(H1N1) virus strains is complex and diverse, and antigenic variation may affect vaccine effectiveness. Therefore, it is recommended to enhance genomic surveillance of influenza viruses, evaluate vaccine suitability, and implement more targeted prevention and control strategies against imported influenza viruses.

Lipotoxicity is a pivotal factor that initiates and exacerbates liver injury and is involved in the development of metabolic-associated fatty liver disease (MAFLD). However, there are few reported lipotoxicity inhibitors. Here, we identified a natural anti-lipotoxicity candidate, HN-001, from the marine fungus Aspergillus sp. C1. HN-001 dose- and time- dependently reversed palmitic acid (PA)-induced hepatocyte death. This protection was associated with IRE-1α-mediated XBP-1 splicing inhibition, which resulted in suppression of XBP-1s nuclear translocation and transcriptional regulation. Knockdown of XBP-1s attenuated lipotoxicity, but no additional ameliorative effect of HN-001 on lipotoxicity was observed in XBP-1s knockdown hepatocytes. Notably, the ER stress and lipotoxicity amelioration was associated with PLA2. Both HN-001 and the PLA2 inhibitor MAFP inhibited PLA2 activity, reduced lysophosphatidylcholine (LPC) level, subsequently ameliorated lipotoxicity. In contrast, overexpression of PLA2 caused exacerbation of lipotoxicity and weakened the anti-lipotoxic effects of HN-001. Additionally, HN-001 treatment suppressed the downstream pro-apoptotic JNK pathway. In vivo, chronic administration of HN-001 (i.p.) in mice alleviated all manifestations of MAFLD, including hepatic steatosis, liver injury, inflammation, and fibrogenesis. These effects were correlated with PLA2/IRE-1α/XBP-1s axis and JNK signaling suppression. These data indicate that HN-001 has therapeutic potential for MAFLD because it suppresses lipotoxicity, and provide a natural structural basis for developing anti-MAFLD candidates.

ObjectiveTo predict the incidence trend of influenza-like illness proportion （ILI%） in Shanghai using the seasonal autoregressive integrated moving average model （SARIMA）， and to provide an important reference for timely prevention and control measures. MethodsTime series analysis was performed on ILI% surveillance data of Shanghai Municipal Center for Disease Control and Prevention from the 15^th week of 2015 to the 52^nd week of 2019， and a prediction model was established. Seasonal autoregressive integrated moving average （SARIMA） model was established using data from the foregoing 212 weeks， and prediction effect of the model was evaluated using data from the latter 36 weeks. ResultsFrom the 15^th week of 2015 to the 52^nd week of 2019， the average ILI% in Shanghai was 1.494%， showing an obvious epidemic peak. SARIMA（1，0，0） （2，0，0） ₅₂ was finally modeled. The residual of the model was white noise sequence， and the true values were all within the 95% confidence interval of the predicted values. ConclusionSARIMA（1，0，0） （2，0，0） ₅₂ can be used for the medium term prediction of ILI% in Shanghai， and can play an early warning role for the epidemic and outbreak of influenza in Shanghai.

Sexual and gender minorities have social behavioral characteristics such as aggregation， mobility， exclusivity， and concealment， which may be associated with the transmission of infectious diseases in this group. This paper aims to explore the relationship between the sociality of this group and its transmission and prevention and control of infectious diseases， emphasize the importance of paying attention to the transmission of sexually transmitted diseases and respiratory diseases in sexual and gender minorities. This paper puts forward some thoughts for infectious disease prevention and control of this group in the future.

Objective:To evaluate the performance of the influenza surveillance network and compare the epidemic intensity of influenza during 2014-2020 in Shanghai.Methods:Based on the weekly reports of influenza-like illness (ILI) and laboratory-confirmed influenza cases from January 1, 2014 to December 31, 2020. This study first evaluated the data reporting and specimen collection of ILI cases for each sentinel hospital, and then calculated the percentage of ILI (ILI%), the proportion of specimens tested positive for influenza, and the incidence of influenza among all ILI outpatient and emergency visits to measure the epidemic intensity of influenza. Finally, seasonal autoregressive integrated moving average (ARIMA) model was applied to quantify the changes in epidemic intensity of influenza in 2020.Results:The proportion of influenza surveillance sentinel hospitals with a score of less than 5 in the evaluation of ILI data reporting and samples collection were 9.68% and 21.05% in 2020 in Shanghai, respectively. ILI% was estimated to be 1.51% (95% CI: 1.50%-1.51%) and 2.31% (95% CI: 2.30%-2.32%), respectively for 2014-2019 and 2020; the proportion of specimens tested positive was 24.27% (95% CI: 24.02%- 24.51%) and 7.15% (95% CI: 6.78%-7.54%), respectively; and the incidence of influenza was 3.66‰ (95% CI: 3.62‰-3.70‰) and 1.65‰ (95% CI: 1.57‰-1.74‰), respectively. ARIMA model showed that ILI% was increased by 45.25% in 2020 in Shanghai, and the proportion of specimens tested positive and the incidence of influenza were reduced by 78.45% and 51.80%, respectively. Conclusions:In 2020, the performance of influenza surveillance system has changed, ILI% has increased, the proportion of specimens tested positive and the incidence of influenza has decreased in Shanghai. The change in the quality of influenza surveillance is also a potential factor affecting the epidemic intensity of influenza. In the future, the quality control of influenza surveillance network still needs to be further strengthened.

Objective:To study the infection status and epidemiological characteristics of parainfluenza virus (PIV) in acute respiratory tract infection adult cases in Shanghai from 2015 to 2021, and to provide a scientific basis for preventing and controlling PIV.Methods:Acute respiratory tract infections were collected from 13 hospitals in Shanghai from 2015 to 2021. Relevant information was registered, and respiratory specimens were sampled to detect respiratory pathogens by multiplex PCR.Results:A total of 5 104 adult acute respiratory tract infection cases were included; the overall positive rate of the respiratory pathogens was 29.37% (1 499/5 104). The positive rate of PIV was 2.61% (133/5 104), compared with 2.32% (55/2 369) and 2.85% (78/2 735) in influenza-like cases (ILI) and severe acute respiratory infection (SARI) cases, respectively. Among them, PIV3 accounted for the highest proportion (62.41%, 83/133), followed by PIV1 (18.80%, 25/133), PIV2 (9.77%, 13/133), and PIV4 (9.02%, 12/133). The incidence of PIV-positive cases was mainly distributed in the first and second quarters, accounting for 62.41% (83/133). The difference in the incidence in each quarter was significant ( χ2=24.78, P<0.001). Mixed infection accounted for 18.80% (25/133) of 133 PIV-positive cases, the mixed infection rates of ILI and SARI were 18.18% (10/55) and 19.23% (15/78), respectively, and the main mixed pathogen of PIV was coronavirus 229E. Conclusions:There are a certain proportion of PIV-positive acute respiratory tract infection cases in Shanghai. It is necessary to strengthen the etiological surveillance in acute respiratory tract infection cases, especially the mixed infection of PIV and other pathogens.

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.

ObjectiveTo conduct on-site epidemiological investigation， emergency response， tracing of infection source and analysis of a confirmed COVID-19 case of a foreign airline cargo service staff member in Shanghai’s international airport， aiming to provide reference for prevention of imported COVID-19 cases under regular prevention and control of COVID-19. MethodsA retrospective field epidemiological investigation was conducted to collect information of basic characteristics， illness onset， diagnosis， treatment， clinical manifestations， exposure history and risk factors within 14 days before onset， close contacts， close contacts of close contacts， and key places related to activity trajectories. Respiratory tract specimens of cases and contacts were collected for detection of SARS-CoV-2 by real time RT-PCR （rRT-PCR）. Emergency response， including infection source analysis and contact management， was conducted. ResultsThe case developed pharyngeal itch on July 28， 2021， and fever on the 30th， and went to the hospital for treatment twice on the 31st. Because his specimen was positive for SARS-CoV-2 by rRT-PCR on August 1， he was isolated and treated on August 2 and diagnosed as a confirmed case of COVID-19. The case was a foreign airline cargo service member at an international airport. The two regular nucleic acid screenings of him as a high-risk occupation on July 21 and 28 were negative. He did not leave Shanghai within 14 days before the onset of illness. During July 22nd and 23rd， he was repeatedly exposed during work to the high-risk environment that may have been contaminated by SARS-CoV-2 and had contact with the crew of foreign airlines， and the personal protection was not standardized. None of the 67 close contacts and 567 close contacts of close contacts in Shanghai showed symptoms during the 14-day medical quarantine， and the specimens of them were all negative for SARS-CoV-2 by rRT-PCR. The results of genome sequencing analysis showed that the genomic homology between the virus of the case and the one of recent domestic local epidemic and the recent imported cases was low， and the homology with the overseas Delta mutant strain was higher than that of the domestic Delta mutant strain. ConclusionThe situation of prevention of COVID-19 import is still serious. It is necessary to conduct regular nucleic acid screening for high-risk occupational groups， strengthen the diagnosis and reporting awareness of medical institutions， effectively implement the prevention and control measures for people， objects， and environment at international airports， and further enhance the public's awareness of personal protection.

Objective:To discuss the challenges and problems of the prevention and control of emerging infectious diseases in Shanghai as a megacities.Methods:An imported case of cutaneous anthrax occurred in Shanghai on May 30, 2019. Shanghai Municipal Center for Disease Control & Prevention conducted an epidemiological investigation and treatment of the cases; after this case, the data of patients with cutaneous anthrax were collected, and an epidemiological study was conducted. Meanwhile, the wound and blood samples of the patient were collected for laboratory testing.Results:Of the seven wound samples of the patient, 6 were positive for the Bacillus anthracis nucleic acid test, and the double serological test results showed a 4-fold increase in the titer of anthrax antibodies. Shanghai CDC conducted an epidemiological investigation of the confirmed cases and observed its contacts. After treatment, the patients recovered, and no other issues appeared among the 19 contacts. Conclusions:Shanghai must strengthen the training of clinicians on emerging infectious diseases to achieve early detection, diagnosis, and treatment of imported infectious diseases and reduce the incidence, spread, and death of the diseases. At the same time, multi-department joint prevention and control are needed to prevent and control secondary cases.