To analyze the epidemiological characteristics of COVID-19 in Fujian Province from the 49th week of 2022 to the 5th week of 2023,after further optimization of China's COVID-19 prevention and control measures on December 7,2022(the 49th week of 2022),this study used multi-dimensional surveillance data to dynamically assess population infection levels and their changing trends.The aim of the study was to provide a scientific basis for early warning of epidemic risk,medical resource allocation,and evalu-ation of socio-economic impact.A multi-source data surveillance system was constructed,encompassing surveillance of fever clinics at medical institutions(weekly collection of visits,positive nucleic acid and antigen test results,inpatients,and severe cases in sec-ondary or above hospitals),population nucleic acid test monitoring(weekly person-times and positivity rates of single-tube tests from the provincial system),sentinel hospital monitoring(weekly proportion of influenza-like illness visits at 18 sentinel hospitals and re-lated viral testing data),and monitoring of novel coronavirus variants(weekly systematic collection of genomic sequences of local and imported cases).Line charts were plotted weekly,and time series analysis,molecular epidemiological methods,and an improved SEIAR model were used to simulate epidemic spread.During the study period,the COVID-19 epidemic in Fujian Province exhibited three distinct stages.In the infection peak stage(52nd week of 2022),the provincial fever clinic visits reached 606 893 person-times,and a 49.2%positivity rate in population single-tube nucleic acid tests and 63.8%positivity rate in sentinel hospital monitoring were observed.In the medical load peak stage(2nd week of 2023),274 460 inpatients and 28 487 severe cases were recorded.In the epidemic decline stage(4th to 5th weeks of 2023),fever clinic visits decreased by 96.3%with respect to the peak,the single-tube nucleic acid test positivity rate decreased to 6.3%,and the sentinel hospital COVID-19 nucleic acid test positivity rate was 6.4%.All 508 sequenced local cases were Omicron variants,predominantly BA.5.2 and its sub-lineages(67.4%).Among 56 imported se-quenced cases,BA.5.2 and its sub-lineages accounted for 50.0%,and 16.1%comprised nine variants of interest including XBB and BQ.The model predicted the infection peak in the 52nd week of 2022,whereas the hospitalization peak lagged by approximately 10.6 days.Multi-source data monitoring revealed a three-stage development of the COVID-19 epidemic in Fujian.The BA.5.2 strain was dominant during the epidemic.The combination of multi-source monitoring data and modeling provides important references for epi-demic prevention and control,and highlights the need to improve the monitoring system in follow-up.

To analyze the epidemiological characteristics of COVID-19 in Fujian Province from the 49th week of 2022 to the 5th week of 2023,after further optimization of China's COVID-19 prevention and control measures on December 7,2022(the 49th week of 2022),this study used multi-dimensional surveillance data to dynamically assess population infection levels and their changing trends.The aim of the study was to provide a scientific basis for early warning of epidemic risk,medical resource allocation,and evalu-ation of socio-economic impact.A multi-source data surveillance system was constructed,encompassing surveillance of fever clinics at medical institutions(weekly collection of visits,positive nucleic acid and antigen test results,inpatients,and severe cases in sec-ondary or above hospitals),population nucleic acid test monitoring(weekly person-times and positivity rates of single-tube tests from the provincial system),sentinel hospital monitoring(weekly proportion of influenza-like illness visits at 18 sentinel hospitals and re-lated viral testing data),and monitoring of novel coronavirus variants(weekly systematic collection of genomic sequences of local and imported cases).Line charts were plotted weekly,and time series analysis,molecular epidemiological methods,and an improved SEIAR model were used to simulate epidemic spread.During the study period,the COVID-19 epidemic in Fujian Province exhibited three distinct stages.In the infection peak stage(52nd week of 2022),the provincial fever clinic visits reached 606 893 person-times,and a 49.2%positivity rate in population single-tube nucleic acid tests and 63.8%positivity rate in sentinel hospital monitoring were observed.In the medical load peak stage(2nd week of 2023),274 460 inpatients and 28 487 severe cases were recorded.In the epidemic decline stage(4th to 5th weeks of 2023),fever clinic visits decreased by 96.3%with respect to the peak,the single-tube nucleic acid test positivity rate decreased to 6.3%,and the sentinel hospital COVID-19 nucleic acid test positivity rate was 6.4%.All 508 sequenced local cases were Omicron variants,predominantly BA.5.2 and its sub-lineages(67.4%).Among 56 imported se-quenced cases,BA.5.2 and its sub-lineages accounted for 50.0%,and 16.1%comprised nine variants of interest including XBB and BQ.The model predicted the infection peak in the 52nd week of 2022,whereas the hospitalization peak lagged by approximately 10.6 days.Multi-source data monitoring revealed a three-stage development of the COVID-19 epidemic in Fujian.The BA.5.2 strain was dominant during the epidemic.The combination of multi-source monitoring data and modeling provides important references for epi-demic prevention and control,and highlights the need to improve the monitoring system in follow-up.

Abstract: Objective To analyze the epidemiological characteristics of viral hepatitis E in Fujian Province from 2012-2021, and to provide scientific evidence for the prevention and control of hepatitis E in the future. Methods Descriptive epidemiological method was used to analyze hepatitis E cases in Fujian Province from 2012 to 2021. Results From 2012 to 2021, a total of 8 877 cases of hepatitis E were reported in Fujian Province from 2012-2021. The overall incidence rate showed a decreasing trend (χ2trend =458.14, P<0.001), with the lowest incidence rate of 1.32/100 000 in 2020 and an annual average incidence rate of 2.29/100 000 per year. The incidence was higher in winter and spring, with the months of March and April having the highest number of reported cases (2 146, 24.17%) and the fewest cases were reported in September (571, 6.43%). The difference in reported incidence rates between cities was statistically significant (χ2=1 877.75, P<0.01). The comprehensive experimental zone of Pingtan had the highest average reported incidence rate of 6.03/100 000, while Zhangzhou had the lowest at 0.94/100 000. The number of male cases was higher than the number of female cases, with a male to female ratio of 2.04∶1. The disease was most prevalent among middle-aged and elderly individuals, with the age group of 40-<65 years having the highest number of reported cases, accounting for 57.44% (5 099/8 877) of all cases. The age group of 50-<55 years had the highest reported incidence, with the number of reported cases increasing with age below 50 years, but decreasing with age over 50 years. As for occupational distribution, peasants had the highest proportion of the disease, accounting for 34.49% (3 062 cases) of the total cases. Conclusions The reported incidence rate of hepatitis E in Fujian showed a downward from 2012 to 2021. Due to the impact of COVID-19, incidence of the lowest was 2020, but it did not reflect the true situation of the disease, which may have affected trend of hepatitis E. In order to control and reduce the incidence of hepatitis E, efforts should be made to increase publicity and education on health knowledge and vaccination among key areas and populations, strengthen monitoring and diagnostic capability, and implement comprehensive prevention and control measures.

Objective:To understand the genome characteristics of group A rotavirus (RVA) strains among hospitalized children under 5 years of age with acute diarrhea in Fuzhou sentinel hospital in 2020.Methods:The ELISA method was used for screening RVA-positive stool samples of hospitalized children under 5 years of age, then 11 gene segments of RVA-positive samples were sequenced and typed after amplification by RT-PCR, and their homology and phylogenetic analysis were performed by Molecular Evolutionary Genetics Analysis (MEGA).Results:Twenty RVA whole genome sequences were successfully obtained, including 4 kinds of G/P gene combinations-G9P[8] (55%), G3P[8] (25%), G8P[8] (15%) and G2P[4] (5%). DS-1-like reassortant strains accounted for 40% of the whole genomes. Strains of the same type have high sequence homology, are closely related to the virus strains that currently circulating in the world. There are mutations at multiple important antigenic sites on VP7, VP4 and NSP4 fragments. The variation of amino acid substitutions of VP7, VP4 and NSP4 fragments is complicated, and there are many amino acid substitutions in the antigenic regions.Conclusions:G3P[8] and G8P[8] DS-1-like reassortants were detected for the first time in Fuzhou, amino acid substitutions were observed in the antigenic regions of the VP7, VP4 and NSP4 gene. Due to the emergence of uncommon DS-1-like reassortant strains and multiple important antigenic regions substitutions, it is necessary to continuously monitoring genome characteristics of RVA strains to provide scientific evidence for the pandemic prevention and vaccine immunization strategies.

Objective:To identify the viral etiologies and epidemic characteristics of acute respiratory infection (ARI) in Fuzhou.Methods:The information and respiratory tract specimens of ARI cases from three different types of hospitals in Fuzhou were collected in 2019. Real-time quantitative fluorescent PCR (Polymerase Chain Reaction, PCR) was uesd to detect adenovirus (AdV) and human bocavirus (HBoV), Real-time quantitative fluorescent RT-PCR (Reverse Transcription-PCR, RT-PCR) was used to detect influenza virus A/B (IFV-A/B), respiratory syncytial virus (RSV), parainfluenza virus 1-4 (PIV-1~4), human metapneumovirus (HmpV), coronavirus (CoV)-229E/OC43/HKU1/NL63 and rhinovirus (RV). Chi-square test and Fisher exact test were used to analyze the epidemiological characteristics of ARI cases. Results:Of the 726 ARI cases enrolled, 316 (43.53%) were positive for at least one viral pathogen, of which, 40 cases had dual infection and 9 had triple infection. The viral infection rates in different age groups were significantly different. The main viral pathogens in ARI in Fuzhou in 2019 were IFVs (12.40%), followed by Adv (10.61%), RV (8.82%), and RSV (5.51%). The AdV infection was more common in male ARI cases, and IFV-B, PIV, RSV, RV, and AdV were identified more commonly in children. In addition, the infection with IFVs, RSV, and RV had obvious seasonality.Conclusions:The main pathogens of ARI cases in Fuzhou in 2019 include IFVs, AdV, RV, RSV, etc. The infection of respective virus in ARI cases represent different age-distribution and seasonality.

Objective: To study the etiological characteristics of an imported Chikungunya fever (CHIK) epidemic in Fujian province in 2018. Methods: Serum samples collected at different days after the onset of the two CHIK cases were detected by real-time RT-PCR and ELISA. Structural protein E1 gene was amplified by RT-PCR and sequenced for nucleotide characteristics analysis and phylogenetic tree analysis. Results: RNA of Chikungunya virus (CHIKV) was detected in the 4 serum samples collected on the first 5 days of the disease, and the earliest IgM antibodies were detected in specimens on the 5th day of the disease, however, IgG antibodies were only detected in specimen on 10th day. Compared with the S27-African prototype strain, 12 mutant points were found in the amino acids of E1 genes in this study. The E1 genes of the two CHIK cases were exactly the same, and they were closest to the evolutionary relationship with the strain isolated in the Philippines in 2014. Their genotype was Asian genotype. Conclusions This epidemic was confirmed to have been imported from the Philippines after the infection with the Asian genotype CHIKV, which suggests that Fujian province should strengthen the monitoring of persons entering from the CHIK epidemic area, so as to prevent imported cases from causing local outbreaks.

Objective To evaluate the safety of national immunization program (NIP) vaccines and non-NIP vaccines in Fujian Province from 2011 to 2015.Methods The adverse events following immunization (AEFI) case information reported in Fujian Province from 2011 to 2015 was collected from the National AEFI Information Management System and vaccination data of NIP vaccines (11 species) and nonNIP vaccines (19 species) in the same period in Fujian Province were collected from the National Immunization Program Information Management System.The collected monitoring data were descriptively analyzed.The total and severe AEFI reporting rates and their 95％ confidence intervals (CI) were calculated.Results From 2011 to 2015,a total of 70 976 300 doses of vaccines were inoculated in Fujian Province and a total of 8 987 cases of AEFI were reported,including 192 cases (2.14％) of severe AEFI.The incidence (95％CI) of reported AEFI was 12.66 (12.40-12.93) per 100 000 doses and the incidence (95％CI) of reported severe AEFI was 2.71 (2.34-3.12) per one million doses.A total of 55 702 100 doses of NIP vaccines were inoculated and 7 347 cases of AEFI were reported,of which 138 (1.88％) were severe AEFI cases.The incidence (95％ CI) of reported AEFI was 13.19 (12.89-1.49)per 100 000 doses of NIP vaccines and the incidence (95％ CI) of reported severe AEFI was 2.48 (2.08-2.93) per one million doses.Among the 11 NIP vaccines,the incidence (95％ CI) of reported AEFI ranged from 0.95 (0.88-1.13) per 100 000 doses to 43.71 (40.72-46.75) per 100 000 doses and the incidence (95％ CI) of reported severe AEFI ranged from 1.04 (0.32-1.76) per one million doses to 6.41 (2.78-10.04) per one million doses.A total of 15 271 600 doses of non-NIP vaccines were inoculated and 1 640 cases of AEFI were reported,of which 54 (3.54％) were severe AEFI cases.The total incidence (95％ CI) of reported AEFI was 10.74 (10.23-11.27) per 100 000 doses and the incidence (95％ CI) of reported severe AEFI was 3.54 (2.66-4.61) per one million doses.Among the 19 non-NIP vaccines,the incidence (95 ％ CI) of reported AEFI ranged from 2.06 (0.38-3.71) per 100 000 doses to 45.22 (35.29-55.10)per 100 000 doses and the incidence (95％ CI) of reported severe AEFI ranged from 0.52 (0-1.53) per one million doses to 20.89 (0-44.51) per one million doses.Conclusion From 2011 to 2015,the incidences of reported AEFI and severe AEFI for NIP and non-NIP vaccines circulated in Fujian Province were low,which had good safety.

Objective To evaluate the safety of national immunization program (NIP) vaccines and non-NIP vaccines in Fujian Province from 2011 to 2015.Methods The adverse events following immunization (AEFI) case information reported in Fujian Province from 2011 to 2015 was collected from the National AEFI Information Management System and vaccination data of NIP vaccines (11 species) and nonNIP vaccines (19 species) in the same period in Fujian Province were collected from the National Immunization Program Information Management System.The collected monitoring data were descriptively analyzed.The total and severe AEFI reporting rates and their 95％ confidence intervals (CI) were calculated.Results From 2011 to 2015,a total of 70 976 300 doses of vaccines were inoculated in Fujian Province and a total of 8 987 cases of AEFI were reported,including 192 cases (2.14％) of severe AEFI.The incidence (95％CI) of reported AEFI was 12.66 (12.40-12.93) per 100 000 doses and the incidence (95％CI) of reported severe AEFI was 2.71 (2.34-3.12) per one million doses.A total of 55 702 100 doses of NIP vaccines were inoculated and 7 347 cases of AEFI were reported,of which 138 (1.88％) were severe AEFI cases.The incidence (95％ CI) of reported AEFI was 13.19 (12.89-1.49)per 100 000 doses of NIP vaccines and the incidence (95％ CI) of reported severe AEFI was 2.48 (2.08-2.93) per one million doses.Among the 11 NIP vaccines,the incidence (95％ CI) of reported AEFI ranged from 0.95 (0.88-1.13) per 100 000 doses to 43.71 (40.72-46.75) per 100 000 doses and the incidence (95％ CI) of reported severe AEFI ranged from 1.04 (0.32-1.76) per one million doses to 6.41 (2.78-10.04) per one million doses.A total of 15 271 600 doses of non-NIP vaccines were inoculated and 1 640 cases of AEFI were reported,of which 54 (3.54％) were severe AEFI cases.The total incidence (95％ CI) of reported AEFI was 10.74 (10.23-11.27) per 100 000 doses and the incidence (95％ CI) of reported severe AEFI was 3.54 (2.66-4.61) per one million doses.Among the 19 non-NIP vaccines,the incidence (95 ％ CI) of reported AEFI ranged from 2.06 (0.38-3.71) per 100 000 doses to 45.22 (35.29-55.10)per 100 000 doses and the incidence (95％ CI) of reported severe AEFI ranged from 0.52 (0-1.53) per one million doses to 20.89 (0-44.51) per one million doses.Conclusion From 2011 to 2015,the incidences of reported AEFI and severe AEFI for NIP and non-NIP vaccines circulated in Fujian Province were low,which had good safety.

Objective To investigate the genetic characteristics and mutations in hemagglutinin ( HA) genes of influenza A subtype H3N2 viruses isolated in Fujian province during 2014—2016. Methods HA gene fragments of 44 randomly selected influenza A (H3N2) viruses were amplified by RT-PCR and then sequenced by Sanger sequencing. Obtained sequences were analyzed by bioinformatics software and on-line websites. Results Pair-wise similarity among HA genes of the 44 strains was between 97. 3%-100. 0% at nucleotide level. The average variations between epidemic strains and corresponding vaccine strains in the year of 2014, 2015 and 2016 were 0. 012, 0. 008 and 0. 009, respectively. The genotype of epidemic strains in 2014 was 3C. 3a rather than 3C. 1 of the vaccine strain. Notably, variations at some antigenic sites, re-ceptor binding sites ( RBSs) and N-Glycosylation sites were identified despite the fact that the genotypes were identical between epidemic and vaccine strains in 2015 and 2016. Conclusion Variations at the HA genes of influenza A (H3N2) viruses in Fujian province occurred during the year of 2014—2016, reflecting the ability of circulating strains to escape the vaccine-induced immunity. Sustainable influenza surveillance and prompt identification of viral variants would benefit influenza prevention and control.

Objective: To provide effective reference of laboratory detection and prevention-control in avian influenza epidemic via analyzing the detection result of the first case infected avian influenza H5N6 virus in Fujian province. Methods: The viral RNA was extracted from the patient’s throat swab and specimens of surrounding environment, and detected by real-time RT-PCR. The gene sequences of HA and NA gene segments were obtained by RT-PCR and sequencing, the evolution characteristics of the virus were elementarily analyzed by bioinformatics. Results: The avian influenza H5N6 virus was confirmed from the patient’s throat swab, termed influenza A/Fujian-Sanyuan/21099/2017(H5N6)virus. The throat swabs of case from 5 different time points were collected and the H5N6 nucleic acid were detected from the first three times collection. Among 43 specimens of surrounding environment, there were 16 H5 virus samples. The HA and NA gene segments of A/Fujian-Sanyuan/21099/2017 were closely related to A/Cygnus atratus/Hubei/2Z2-O/2016(H5N8) and A/chicken/Hubei/ZYSJF16/2016(H5N6), with a similarity of 99.6% and 99.0% respectively. The cleavage site of HA gene contained multiple basic amino acids. Conclusions The suspected case was the first case infected with avian influenza H5N6 virus in Fujian province, and the HA and NA genes of virus were highly similar to those of H5N8 and H5N6 virus respectively.