Objective:To analyze the epidemiological characteristics and genetic evolution of human coronavirus OC43（HCoV-OC43）in Hangzhou from 2018 to 2023，and provide molecular epidemiological basis for the prevention and control of HCoV-OC43 infection.Methods:A total of 11 904 samples of cases with acute respiratory tract infection were collected from two sentinel hospitals in Hangzhou. The collection period was from January 2018 to December 2023. HCoV-OC43 was detected by real-time fluorescent quantitative RT-PCR. The positive samples were amplified by PCR using specific primers，and the amplified products were sequenced using third-generation nanopore technology for the whole genome. The genetic evolution features were analyzed.Results:A total of 265 HCoV-OC43 positive samples were detected，with a positive detection rate of 2.23%（265/11 904）. There was no significant difference in detection rate between males and females（χ 2=0.042， P>0.05）；the detection rate varied significantly among different age groups（χ 2=60.104， P<0.01），with higher detection rates observed in children under five years old and individuals over 65 years old. The infection peaks in 2018-2019 and 2023 occurred in spring and summer，while the infection peak in 2020-2022 was in summer and autumn. A total of 85 complete HCoV-OC43 whole genome sequences were obtained through high-throughput sequencing. The evolutionary analysis indicated that the K genotype was predominant in Hangzhou from 2018 to 2023. In 2019，both J and K genotypes co-existed. In 2023，a new genotype，temporarily named genotype L，was discovered，which originated from genotypes J and K. The K genotype had 22 specific amino acid variation sites，most of which were located in the important domain of S protein. The J genotype had seven specific amino acid variation sites，most of which were located in non-structural proteins. The new genotype L had 10 specific amino acid mutation sites，which were distributed across six proteins，and these mutation sites had the most extensive coverage. Conclusions:HCoV-OC43 is an important pathogen causing respiratory diseases in children and the elderly in the Hangzhou area，and there are multiple genotypes in the Hangzhou area，with a new recombinant genotype L discovered in 2023.

Objective:To analyze the epidemiological characteristics and genetic evolution of human coronavirus OC43（HCoV-OC43）in Hangzhou from 2018 to 2023，and provide molecular epidemiological basis for the prevention and control of HCoV-OC43 infection.Methods:A total of 11 904 samples of cases with acute respiratory tract infection were collected from two sentinel hospitals in Hangzhou. The collection period was from January 2018 to December 2023. HCoV-OC43 was detected by real-time fluorescent quantitative RT-PCR. The positive samples were amplified by PCR using specific primers，and the amplified products were sequenced using third-generation nanopore technology for the whole genome. The genetic evolution features were analyzed.Results:A total of 265 HCoV-OC43 positive samples were detected，with a positive detection rate of 2.23%（265/11 904）. There was no significant difference in detection rate between males and females（χ 2=0.042， P>0.05）；the detection rate varied significantly among different age groups（χ 2=60.104， P<0.01），with higher detection rates observed in children under five years old and individuals over 65 years old. The infection peaks in 2018-2019 and 2023 occurred in spring and summer，while the infection peak in 2020-2022 was in summer and autumn. A total of 85 complete HCoV-OC43 whole genome sequences were obtained through high-throughput sequencing. The evolutionary analysis indicated that the K genotype was predominant in Hangzhou from 2018 to 2023. In 2019，both J and K genotypes co-existed. In 2023，a new genotype，temporarily named genotype L，was discovered，which originated from genotypes J and K. The K genotype had 22 specific amino acid variation sites，most of which were located in the important domain of S protein. The J genotype had seven specific amino acid variation sites，most of which were located in non-structural proteins. The new genotype L had 10 specific amino acid mutation sites，which were distributed across six proteins，and these mutation sites had the most extensive coverage. Conclusions:HCoV-OC43 is an important pathogen causing respiratory diseases in children and the elderly in the Hangzhou area，and there are multiple genotypes in the Hangzhou area，with a new recombinant genotype L discovered in 2023.

Objective: To investigate the willingness to accept preventive treatments and its related factors among college freshmen with latent tuberculosis infection (LTBI), so as to provide the evidence for preventive treatment intervention measures for students with LTBI. Methods: Cluster sampling method was used to select 368 LTBI freshmen from 8 colleges and universities in Changzhou in September 2023, who conducted a questionnaire survey on the willingness to receive preventive treatment. General demographic data were collected and relevant data were collected using tuberculosis knowledge scale, General Anxiety Disorder-7 (GAD-7), Patient Health Questionnaire-9 (PHQ-9), Adaptation, Partnership, Growth, Affection and Resolve (APGAR), and a self developed Stigma Scale. A binary Logistic regression model was constructed with the willingness to accept preventive treatment as the dependent variable to analyze the willingness to accept preventive treatment and the influencing factors. Results: A total of 253 LTBI college freshmen were willing to take preventive treatment, the acceptance rate was 68.75%. The rate of willingness to accept preventive treatment for LTBI was higher among students whose fathers had an education level of high school, compared to those whose fathers had an education level of junior high school or below ( OR =2.16, P <0.05). LTBI students whose per capita family income was >5 000-10 000 yuan and >10 000 yuan were more willing to accept LTBI preventive treatment than those whose per capita family income was <3 000 yuan ( OR =2.72, 4.46, P <0.05). LTBI students who engaged in physical exercise for more than 2 hours per week were more willing to accept than those who exercised less than 0.5 hours per week ( OR =1.91, P <0.05). LTBI students with high levels of tuberculosis knowledge and stigma were more likely to receive preventive treatment ( OR =1.18, 1.11, P < 0.05). LTBI students with high PHQ-9 ( OR =0.85) and GAD-7 ( OR =0.92) scores were more likely to refuse preventive treatment ( P <0.05). Conclusion The present study revealed a moderate level of willingness of LTBI students to preventive treatment in Changzhou City, and the acceptance is affected by family factors, healthy lifestyles, tuberculosis knowledge and psychological status.

Objective:To investigate the co-infection and phylogenetic analysis of human rhinovirus (HRV) in 2019 novel coronavirus (2019-nCoV) positive samples.Methods:Ten common respiratory viruses, including HRV were detected by real-time fluorescence quantitative polymerase chain reaction (qPCR) in 7 213 samples of 2019-nCoV positive cases and the co-infection characteristics were analyzed. The VP4/VP2 gene fragment of HRV was amplified and sequenced.Phylogenetic trees were constructed.Results:HRV accounted for 1.34% of the 2019-nCoV positive samples (97/7 213), followed by common coronavirus (0.50%, 36/7 213). The co-infection rate of HRV in 2019-nCoV positive samples was significantly different from that of other viruses ( χ2=318.09, P<0.001). There was significant difference in HRV co-infection rate among different age groups ( χ2=36.77, P<0.001), the peak was in<18 years age group. The co-infection rate of HRV had no significant difference in different seasons. The VP4/VP2 gene fragments of 39 HRV strains (40.21%, 39/97) were successfully sequenced and made phylogenetic analysis. There were 10 strains of HRV-A, 9 strains of HRV-B and 20 strains of HRV-C. Seventeen subtypes were identified, of which B6 (66.67%, 6/9) and C15 (70%, 14/20) were the most prevalent and other subtypes were scattered. Conclusions:The co-infection rate of HRV in patients with 2019-nCoV infection was the highest. The highest co-infection rate was in<18 years age group. Group A, B, and C of HRV were found in 2019-nCoV positive samples, and serotypes present diversity.

Objective:To analyze the value of 68Ga-fibroblast activation protein inhibitor (FAPI)-04 PET/CT in the detection of myocardial injury in patients treated with anti-tumor therapy. Methods:A retrospective study was conducted on 164 patients who underwent 68Ga-FAPI-04 PET/CT to evaluate the efficacy of anti-tumor therapy in Renji Hospital, School of Medicine, Shanghai Jiao Tong University between August 2021 and March 2024. The patients were divided into 68Ga-FAPI-04-positive group ( n=63, 36 males, 27 females, age (66.7±9.6) years) and 68Ga-FAPI-04-negative group ( n=101, 42 males, 59 females, age (55.2±14.1) years) based on the uptake of left ventricular myocardium (LVM). Moreover, FAPI-04 uptake was analyzed based on different types and locations, and the corresponding SUV max differences were analyzed by Kruskal-Wallis rank sum test. The differences of SUV max between 68Ga-FAPI-04-positive group and 68Ga-FAPI-04-negative group were analyzed by Mann-Whitney U test. The clinical factors such as gender, age, body mass index (BMI), previous history of coronary heart disease, left ventricular ejection fraction (LVEF), smoking history, hypertension, diabetes, cancer types and immune checkpoint inhibitors (ICIs) treatment were collected, and their predictive values for LVM 68Ga-FAPI-04 uptake were investigated by the binary logistic regression analysis. Results:Fifty patients of the 68Ga-FAPI-04-positive group (79.4%, 50/63) showed focal uptake of LVM, 7 patients (11.1%, 7/63) showed multifocal myocardial uptake, and 6 patients (9.5%, 6/63) showed diffuse myocardial uptake. A total of 127 uptake lesions were found, and most of them were located in the septum (37.8%, 48/127). The SUV max of LVM in 68Ga-FAPI-04-positive group and 68Ga-FAPI-04-negative group were 4.00(3.10, 5.40) and 1.31(1.20, 1.40) respectively ( z=-10.82, P<0.001). Differences of the SUV max among focal uptake group, multifocal myocardial uptake group, and diffuse myocardial uptake group were not significantly different (4.00(3.00, 5.10) vs 7.60(3.60, 9.30) vs 3.95(3.05, 5.05); H=3.81, P=0.149). There is no statistically significant difference either in FAPI uptake among different sites of LVM ( H=1.51, P=0.825). Age, previous history of coronary heart disease, BMI, LVEF and ICIs treatment were independent predictive factors for positive 68Ga-FAPI-04 uptake in the LVM (odds ratio ( OR) values: 0.87-10.43, all P<0.05). Conclusion:68Ga-FAPI-04 PET/CT is a potential new imaging method for the visualization of myocardial injury in patients with anti-tumor therapy.

Objective:To analyze the prevalence of influenza B virus in Hangzhou from 2014 to 2020 and the genetic evolution of seven reassortant strains of influenza B virus.Methods:Influenza viruses were isolated from throat swabs collected from 16 943 patients with influenza-like illness in Hangzhou from January 2014 to December 2020. The subtypes of influenza viruses were identified by real-time RT-PCR. Eight genes ( PB2, PB1, PA, HA, NP, NA, MP and NS) of influenza B viruses were amplified with specific primers and then analyzed with nanopore sequencing and phylogenetic analysis. Results:From January 2014 to December 2020, there were 1 090 influenza B virus-positive samples, including 474 samples of Yamagata lineage and 616 samples of Victoria lineage, were identified in Hangzhou with an overall positive rate of 6.43% (1 090/16 943). Whole genomes of 228 strains of influenza B virus were obtained by nanopore sequencing and seven reassortant strains of influenza B virus were found. There were four reassortant influenza B viruses of Yamagata lineage with NA gene fragments from viruses of Victoria lineage, two strains of Yamagata lineage (H644_BY and H648_BY) with NP and NA gene fragments from Victoria lineage and one strain of Victoria lineage with PB2, PB1, PA and NS gene fragments from Yamagata lineage. Meanwhile, these seven strains possessed several mutations in the antigenic sites of HA and NA genes. Conclusions:Several rare reassortant strains of influenza B virus with epidemic potential were detected in Hangzhou from 2014 to 2020, which indicated that the traditional detection methods should be improved and more attention should be paid to the reassortant influenza B viruses and the match between epidemic and vaccine strains.

Objective:To investigate the epidemic characteristics of influenza in children and the features of severe influenza.Methods:From January 2016 to September 2022, 1 600 samples from hospitalized cases of severe acute respiratory tract infection and 7 660 samples from outpatients with influenza-like illness were collected. Influenza virus was detected by real-time RT-PCR. Other respiratory viruses in the samples of severe hospitalized cases and some samples of outpatients were detected. Clinical features of influenza virus infection and co-infection were analyzed.Results:The positive rate of influenza virus in the 1 600 hospitalized cases of severe acute respiratory infection was 6.63% (106 cases). H1N1, H3N2, BV and BY were deteted in 49.06% (52 cases), 17.92% (19 cases), 29.25% (31 cases) and 3.77% (4 cases) of the 106 cases, respectively. The positive rate of influenza virus in the 7 660 out-patient cases was 15.01% (1 150 cases), and H1N1, H3N2, BV and BY were detected in 22.17% (255 cases), 30.96% (356 cases), 41.39% (476 cases) and 5.48% (63 cases) of the infected cases, respectively. Influenza A (H1N1) virus was more likely to cause severe influenza in children (χ 2=37.978, P<0.001), while seasonal H3N2 and BV strains were less likely to cause severe influenza in children (χ 2=7.871, P=0.005; χ 2=5.948, P=0.015). There was no statistically significant difference in the positive rates of BY lineage in the two groups. Severe influenza mainly occured in the peak season of influenza epidemic. There was no significant difference in the clinical manifestations between the children infected with the four different influenza viruses. In the 106 severe cases of influenza, the co-infection rate of influenza virus with other respiratory viruses was 17.92% (19 cases), while the co-infection rate reached 34.81% (47 cases) in 135 outpatient cases of influenza. The difference in the co-infection rates was statistically significant between outpatient and hospitalized cases (χ 2=10.734, P=0.001). Conclusions:Influenza A (H1N1) virus was more likely to cause severe influenza in infants and young children in comparison with seasonal H3N2 and BV. There was no significant difference in the clinical features of influenza caused by H1N1, H3N2, BV and BY. Co-infection of influenza virus with other respiratory viruses is not a major risk factor for severe influenza in infants.

Objective:To study the epidemiological features of local influenza A(H1N1)pdm09 epidemic strains through analyzing the changes in lineages and to analyze how well the vaccine strains were matched to the circulating strains in Hangzhou.Methods:Of 1 112 clinical specimens from laboratory-confirmed A(H1N1)pdm09 infections in Hangzhou in consecutive seasons from 2009 to 2020, 208 (18.7%) with high viral load (Ct value <30) were randomly selected from 10 influenza epidemics for full-length hemagglutinin gene ( HA) gene sequencing. Genetic variation, evolution and lineage changes of these representative local strains were analyzed by comparison with vaccine strains and reference strains. Results:Since the 2009 pandemic, A(H1N1)pdm09 had become one of the predominant viruses causing seasonal influenza and been reported to co-circulate with influenza A(H3N2) and influenza B viruses in Hangzhou in the past decade. It caused 10 local influenza epidemics in the 12 consecutive seasons from 2009 to 2020. HA gene sequencing revealed complex sources and rapid variation of the local A(H1N1)pdm09 strains. The main epidemic strains often genetically drifted from the recommended northern hemisphere vaccine strains due to lineage changes. Conclusions:This study suggested that it was essential to update the recommended vaccine strains year by year. Besides, enhanced periodic monitoring of influenza A(H1N1)pdm09 strains circulating in the region was important for the prevention and control of influenza A(H1N1)pdm09 infection in the next epidemic season.

Objective:To analyze the epidemiological and etiological characteristics of dengue fever in Hangzhou in 2018.Methods:RT-PCR was used to detect the nucleic acids and analyze the serotypes of dengue viruses (DENV) in serum samples collected from dengue fever cases. Phylogenetic trees based on the E gene sequences of DENV isolated from the serum samples were then constructed and analyzed. Epidemiological characteristics of these dengue fever cases were analyzed. Results:A total of 80 cases of dengue fever were detected in Hangzhou in 2018 with 55 imported cases and 25 indigenous cases (24 caused by DENV-1 and one by DENV-3). These indigenous cases mainly occurred during late July to early October with people above 50 years old accounting for 68%. Phylogenetic analysis showed that DENV-1 strains isolated from the indigenous cases in Yuhang, Jianggan-Shangcheng and Qiantang districts all belonged to genotype Ⅰ, and were respectively closely related to the strains from Indonesia in 2015, Myanmar in 2017, Ningbo in 2018 and Hangzhou imported cases from Thailand in 2018. The indigenous DENV-3 strain belonged to genotype Ⅲ, and shared 99.5% homology with the Singapore strain in 2013.Conclusions:Imported cases accounted for a large fraction of the dengue fever cases in Hangzhou, which brought a high risk to indigenous outbreak. Due to multiple imported cases, the current epidemic presented a characteristic of multiple small-scale outbreaks.

Objective:To analyze the prevalence of influenza B virus in Hangzhou between 2014 and 2019, and the variation in hemagglutinin (HA) and neuraminidase (NA) genes.Methods:Viruses were isolated from throat swabs collected from 10 481 patients with influenza-like illness in Hangzhou from October 2014 to September 2019. The subtypes of influenza viruses were identified by real-time RT-PCR. HA and NA genes of some influenza B virus strains were amplified with specific primers and then analyzed with gene sequencing and phylogenetic analysis.Results:Influenza B virus had circulated in Hangzhou every year since 2014 and caused a much higher morbidity in people aged 5-14 years. The Victoria lineage of influenza B virus circulating in Hangzhou between 2014 and 2019 belonged to the V1A clade, while the Yamagata lineage belonged to the Y3 clade. Homology analysis showed that 124 strains shared 94.67%-100.00% homology in HA gene sequences and 128 strains shared 97.13%-100.00% homology in NA gene sequences. Influenza B virus possessed several mutations in the antigenic sites of HA and NA.Conclusions:Influenza B virus played a critical role in the influenza epidemics in Hangzhou. During 2014 to 2019, genetic mutations in the antigenic sites of HA and NA and reassortant strains were detected, and there was a mismatch between epidemic and vaccine strains. However, no drug-resistant virus was found.