Objective:To analyze the epidemiologic characteristics of avian influenza virus and the molecular characteristics and genetic evolution of H9N2 subtype avian influenza viruses in the live poultry markets in Fujian province in 2021-2023.Methods:Six types of specimens were collected from five cities in Fujian province. The specimens were subjected to nucleic acid detection for influenza A viruses, subtypes H5, H7, and H9 by fluorescence quantitative PCR, and the results were analyzed statistically with χ2 test. Specimens with Ct value less than 31 were screened for targeted amplification and next-generation sequencing of the hemagglutinin (HA) and neuraminidase (NA) genes. Reference sequences were downloaded from the databases, and the characteristics of molecular variation and genetic evolution were analyzed by using bioinformatics softwares. Results:From 2021 to 2023, a total of 1 853 specimens were collected from five cities, with a positive rate of 50.94% for influenza A viruses, including 684 specimens of H9 subtype, 23 specimens of H5 subtype, 1 specimen of H7 subtype, 28 specimens of H5 and H9 subtype, 1 specimen of H7 and H9 subtype, and 207 specimens of unclassified A-type. There were significant differences in the positive detection rates of influenza A viruses in different cities( χ2=461.82, P<0.001). Statistically significant differences in influenza A virus positivity rates across years and quarters( χ2=12.26, P=0.002; χ2=30.12, P<0.001), with higher rates of 56.39% and 55.34% in the first and third quarters, respectively. And the differences in the positive rates of influenza A viruses in different types of specimens were statistically significant( χ2=23.05, P<0.001), with specimens on the cage surface having a positivity rate of 56.09%, which was the highest of all types of specimens. A total of 24 strains of HA and NA genes of H9N2 subtype were fully sequenced. Compared with the sequence of NCBI database, the highest identity of HA gene nucleotide sequences ranged from 97.03% to 99.87%, and the highest identity of NA gene nucleotide sequences ranged from 97.50% to 99.78%.Twenty-three strains with both HA and NA genes belonged to the G57 genotype in the Y280-like evolutionary branch of the Eurasian lineage, and one strain belonged to the Y439-like evolutionary branch of the Eurasian lineage. The cleavage sites of all the strains showed the characteristic of low pathogenicity, and most strains had receptor binding sites characterized by avian-derived and human receptors. Conclusions:The overall positive rate of avian influenza viruses in live poultry markets in Fujian province was relatively high, especially in the first and third quarters, with H9 subtype accounting for the main proportion. Most of H9N2 subtype belonged to the Y280-like G57 genotype with a small number of Y439-like evolutionary branches, suggesting the possibility of genetic recombination and the risk of human infection. Thus, surveillance of avian influenza viruses in the live poultry markets as well as mutation analysis should continue to be strengthened.

This study was aimed at comprehensively understanding the epidemic status of acute hemorrhagic conjunctivitis(AHC)and influencing factors related outbreak in Fujian Province,to provide valuable insights for AHC prevention and control in this region.We conducted a descriptive statistical analysis of epidemiological data for AHC cases.Additionally,clinical samples collected from a 2023 outbreak were subjected to pathogen detection,determination of full-length nucleotide sequences within the VP1 region,genotype identification,and comprehensive analysis.The peak incidence of AHC in 2023 was observed in September and accounted for a substantial proportion(86.39%,5 205/6 025)of the total cases throughout the year.The three areas with the highest incidence rates were Sanming(118.57/100 000),Longyan(53.83/100 000)and Zhangzhou(16.02/100 000).From 2011 to 2022,the inci-dence of AHC in Longyan City was the highest for consecutive 12 years.During the peak AHC outbreak period in Fujian Province in 2023,all 62 conjunctival swabs collected were identified as CVA24v,and 60 complete VP1 sequences were obtained through se-quencing.The nucleotide sequence identity among these 60 sequences ranged from 98.7%to 100%,whereas the amino acid identity ranged from 98.4%to 100%.The highest nucleotide sequence identity was observed for the 2023 strain isolated from Zhongshan,Guangdong Province(rang:99.0%～100%).The 2023 strains in Fujian Province belonged to the GIV genotype,and L16I represented a potential unique amino acid variation within the sequence.CVA24v was the causative agent responsible for this AHC epidemic,and its GIV genotype is currently the dominant type in China.Future efforts should prioritize AHC prevention and control measures cen-tered in key cities.Monitoring and early warning of AHC in the whole province should be strengthened before September each year,and the variation of pathogen nucleic should also be tracked in time.

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.

This study was aimed at comprehensively understanding the epidemic status of acute hemorrhagic conjunctivitis(AHC)and influencing factors related outbreak in Fujian Province,to provide valuable insights for AHC prevention and control in this region.We conducted a descriptive statistical analysis of epidemiological data for AHC cases.Additionally,clinical samples collected from a 2023 outbreak were subjected to pathogen detection,determination of full-length nucleotide sequences within the VP1 region,genotype identification,and comprehensive analysis.The peak incidence of AHC in 2023 was observed in September and accounted for a substantial proportion(86.39%,5 205/6 025)of the total cases throughout the year.The three areas with the highest incidence rates were Sanming(118.57/100 000),Longyan(53.83/100 000)and Zhangzhou(16.02/100 000).From 2011 to 2022,the inci-dence of AHC in Longyan City was the highest for consecutive 12 years.During the peak AHC outbreak period in Fujian Province in 2023,all 62 conjunctival swabs collected were identified as CVA24v,and 60 complete VP1 sequences were obtained through se-quencing.The nucleotide sequence identity among these 60 sequences ranged from 98.7%to 100%,whereas the amino acid identity ranged from 98.4%to 100%.The highest nucleotide sequence identity was observed for the 2023 strain isolated from Zhongshan,Guangdong Province(rang:99.0%～100%).The 2023 strains in Fujian Province belonged to the GIV genotype,and L16I represented a potential unique amino acid variation within the sequence.CVA24v was the causative agent responsible for this AHC epidemic,and its GIV genotype is currently the dominant type in China.Future efforts should prioritize AHC prevention and control measures cen-tered in key cities.Monitoring and early warning of AHC in the whole province should be strengthened before September each year,and the variation of pathogen nucleic should also be tracked in time.

Objective:To analyze the epidemiologic characteristics of avian influenza virus and the molecular characteristics and genetic evolution of H9N2 subtype avian influenza viruses in the live poultry markets in Fujian province in 2021-2023.Methods:Six types of specimens were collected from five cities in Fujian province. The specimens were subjected to nucleic acid detection for influenza A viruses, subtypes H5, H7, and H9 by fluorescence quantitative PCR, and the results were analyzed statistically with χ2 test. Specimens with Ct value less than 31 were screened for targeted amplification and next-generation sequencing of the hemagglutinin (HA) and neuraminidase (NA) genes. Reference sequences were downloaded from the databases, and the characteristics of molecular variation and genetic evolution were analyzed by using bioinformatics softwares. Results:From 2021 to 2023, a total of 1 853 specimens were collected from five cities, with a positive rate of 50.94% for influenza A viruses, including 684 specimens of H9 subtype, 23 specimens of H5 subtype, 1 specimen of H7 subtype, 28 specimens of H5 and H9 subtype, 1 specimen of H7 and H9 subtype, and 207 specimens of unclassified A-type. There were significant differences in the positive detection rates of influenza A viruses in different cities( χ2=461.82, P<0.001). Statistically significant differences in influenza A virus positivity rates across years and quarters( χ2=12.26, P=0.002; χ2=30.12, P<0.001), with higher rates of 56.39% and 55.34% in the first and third quarters, respectively. And the differences in the positive rates of influenza A viruses in different types of specimens were statistically significant( χ2=23.05, P<0.001), with specimens on the cage surface having a positivity rate of 56.09%, which was the highest of all types of specimens. A total of 24 strains of HA and NA genes of H9N2 subtype were fully sequenced. Compared with the sequence of NCBI database, the highest identity of HA gene nucleotide sequences ranged from 97.03% to 99.87%, and the highest identity of NA gene nucleotide sequences ranged from 97.50% to 99.78%.Twenty-three strains with both HA and NA genes belonged to the G57 genotype in the Y280-like evolutionary branch of the Eurasian lineage, and one strain belonged to the Y439-like evolutionary branch of the Eurasian lineage. The cleavage sites of all the strains showed the characteristic of low pathogenicity, and most strains had receptor binding sites characterized by avian-derived and human receptors. Conclusions:The overall positive rate of avian influenza viruses in live poultry markets in Fujian province was relatively high, especially in the first and third quarters, with H9 subtype accounting for the main proportion. Most of H9N2 subtype belonged to the Y280-like G57 genotype with a small number of Y439-like evolutionary branches, suggesting the possibility of genetic recombination and the risk of human infection. Thus, surveillance of avian influenza viruses in the live poultry markets as well as mutation analysis should continue to be strengthened.

Objective:To profile the distribution of avian influenza virus in poultry-related environment in poultry industry developed area in Fujian province, an investigation was conducted in Nanping city from Dec.2021 to Dec.2023.Methods:The samples from multiple types of external environment related to poultry in Nanping city were collected from Dec. 2021 to Dec. 2023, and the real-time fluorescence quantitative RT-PCR used to detect and subtype the influenza A virus (FluA). SPSS 26.0 software was used to analyze the distribution characteristics of FluA in poultry-related environment and the differences in time, places and sample types.Results:The overall positive rate of FluA in samples from poultry-related environment was 49.16% (1 435/2 919). The positive rates of H3, H5, H9 and H10 subtypes were 0.72% (21/2 919), 9.42% (275/2 919), 33.20% (969/2 919), 0.89% (26/2 919) respectively, and no H7 subtype was detected. The positive rate of mixed type (more than one subtype of FluA detected in a same sample) was 6.51% (190/2 919), and the positive rate of unknown subtype (positive for FluA but negative for H3/5/7/9/10) was 11.58% (338/2 919). The higher positive rate of FluA mainly occurred in autumn-winter season (September to February of the following year). In live poultry markets and slaughterhouses, the positive rates of FluA, H9 subtype, mixed type and unknown subtype were significantly higher than that in poultry farms. The positive rate of FluA in poultry drinking water and feces was higher than samples of other types, most of the positive samples were H9 subtype.Conclusions:The positive rate of FluA in poultry-related environment in Nanping city was higher in autumn-winter season. The investigation also showed that higher FluA positive rate in drinking water and feces sample and diversity of the virus existed in the place of multiple types of poultry clustered, such as live poultry markets and slaughterhouses.

Objective:To investigate the molecular epidemiological characteristics of coxsackievirus A16 (CVA16) in Fujian province from 2020 to 2023.Methods:The epidemiological characteristics of CVA16 associated hand, food and mouth disease (HFMD) in Fujian province from 2020 to 2023 was analyzed. The complete VP1 gene of CVA16 was amplified by RT-PCR and then sequenced, and genetic evolution was analyzed by MEGA X and other softwares.Results:From 2020 to 2023, there were 13 120 cases of HFMD in Fujian province, and the proportion of HFMD which caused by CVA16 was 16.5% (2 160/13 120). From 2020 to 2023, the proportion of accounted cases was 4.7% (94/2 019), 14.1% (457/3 243), 47.6% (1 521/3 199) and 1.9% (88/4 659) respectively. HFMD caused by CVA16 was mainly concentrated in children aged 1 to 5 years, and most of them were 3 years old. The genetic evolution and genotype analysis of 92 complete VP1 gene sequences obtained from 2020 to 2023 showed that the genetic distance between CVA16 strains in Fujian province and the prototype strain was far away. The CVA16 genotype in Fujian province from 2020 to 2023 has three clusters of B1a, B1b and B1c, among which the composition ratio of B1a and B1b in Fujian province in 2020 was 40% and 60% respectively. In 2021, B1a and B1b accounted for 81.8% and 18.2% respectively. Only B1a in 2022; in 2023, there were B1a, B1b and B1c, which respectively accounted for 44.4%, 7.4% and 48.2%. During the period from January to September, B1a was the main cluster. After October we observed an emergence of B1c cluster, which had never been found in Fujian province and was rare in China, was detected and became the dominant cluster.Conclusions:The evolutionary cluster of CVA16 dominant changed from B1b in 2020 to B1a in 2021-2023. After October 2023, the newly discovered B1c became the dominant cluster in Fujian province.

Objective:To confirm the cross-provincial long-distance transmission events of Coronavirus Disease 2019 (COVID-19) by lorry drivers, the origin of infections of the cases and the transmission routes were tracked.Methods:Nasopharyngeal swab specimens from five lorry driver cases of COVID-19, found in Zhangzhou city in March, 2022 when the local outbreaks occurred in adjacent Quanzhou city, Fujian province, were collected to perform 2019 novel coronavirus (2019-nCoV) targeted genome amplification and followed by next-generation sequencing. The sequences were submitted to online 2019-nCoV analysis platforms to classify the type of variant and mutation sites. Phylogenetic tree for the viruses were constructed by phylogenetic analysis software. Combined with the epidemiological investigation, the origin of infections of the cases and the transmission routes were deduced.Results:Five complete genome sequences, with 29 770-29 839 bp in length and 99.53% average genomic coverage, of 2019-nCoV were successfully obtained. The viruses were all Omicron variants and further divided into three different subclades of BA.2. Of the five strains of 2019-nCoV, three were highly similar to the viruses of two distinct lineages co-circulated in Quanzhou city during the period of local outbreak of COVID-19, respectively. Phylogenetic analysis also revealed that the viruses from three infected lorry drivers were highly homologous to that from local outbreaks in Quanzhou city. The viruses from the rest two cases had seven to fourteen nucleotide mutations (corresponding to 5-7 amino acid substitutions) when compared with the viruses in local outbreaks in Quanzhou city, which excluded the involvement of the two cases into the transmission chains of local outbreaks. Combined with the field epidemiological investigations, the result revealed that the origin of infection of 2019-nCoV of the two sporadic lorry driver cases was outside of Fujian province.Conclusions:With the aid of high-throughput sequencing and bioinformatics technology combined with field epidemiological investigations, we speculated in this study that at least three origins of infection of 2019-nCoV in five lorry driver cases and cross-provincial long-distance transmission via two sporadic cases infected outside Fujian province when they returned.

Objective:To analyze the epidemiologic characteristics of environmental samples of avian influenza virus in Fujian province from 2017 to 2021, and provide a reference for the prevention and control of avian influenza.Methods:Six types of specimens were collected from four types of environments in six cities in Fujian province. And the specimens were subjected to nucleic acid detection for influenza A, subtypes H5, H7 and H9 by fluorescence quantitative PCR, and the results were analyzed statistically with descriptive epidemiological methods.Results:From 2017 to 2021, a total of 4 214 samples were collected from 6 cities, of which the positive rate of avian influenza virus was 41.53%, and the positive rates of H5, H7 and H9 subtypes were 2.33%, 1.16% and 23.16%, respectively. The positive rate for mixed subtypes of H5 and H7 was 0.05%, the positive rate for mixed subtypes of H5 and H9 was 1.83%, the positive rate for mixed subtypes of H7 and H9 was 0.83%, the positive rate for mixed subtypes of H5, H7 and H9 was 0.09%, and the positive rate of A-type unclassified was 12.08%. The difference in avian influenza virus detection among different monitoring places ( χ2=517.57, P<0.001), different types of specimens( χ2= 51.58, P<0.001), and different cities ( χ2=458.34, P<0.001) was statistically significant. Among different monitoring places, the positive rate of avian influenza virus in urban and rural live poultry markets was the highest. The highest rate of positive detection was found in specimens from the cage surface, cleaning poultry sewage and poultry chopping board surface, with 48.09%, 47.34% and 45.66%, respectively. In terms of different cities, Sanming city had the highest positivity rate (56.00%), while Zhangzhou city had the lowest positivity rate(3.34%). And the positive rate was higher from November to February of the next year and June to August each year. Conclusions:The overall positive rate of avian influenza viruses in Fujian province was relatively high, with H9 subtype accounting for the main proportion. The monitoring of avian influenza viruses in winter, spring and summer should be strengthened. And effective measures should be taken to deal with avian influenza especially in urban and rural live poultry markets.