This study investigated the epidemic status of H3N2 influenza virus and the genetic evolution characteristics of hemagglutinin(HA)and neuraminidase(NA)of H3N2 subtype influenza viruses isolated in Shandong Province during 2023-2024,to understand their compatibility with vaccine strains and drug resistance status.A total of 25 H3N2 subtype influenza virus strains were randomly selected from the strains isolated by the influenza surveillance network laboratory.The HA and NA genes were sequenced with the vaccine strains recommended by the WHO as a reference.Monitoring of sensitivity to oseltamivir and zanamivir was conducted through neuraminidase inhibition experiments.The H3N2 influenza viruses in Shandong Province belonged to the 3C.2a1b.2a.2a.3a.1 clade.Nucleotide sequence analysis revealed that the HA1 and NA genes were closely related to the WHO-recommended vaccine strain A/Darwin/9/2021 for the current season,with homology rates of 97.8%-98.2%and 98.9%-99.3%,respectively.Amino acid sequence analysis indicated 22 amino acid sequence variations in the HA1 protein,and antigenic drift was detected in 8 strains.A glycosylation site was added at position 94 of the HA protein in all 25 strains.Variations occurred in the NA antigenic determinants of some strains.Neuraminidase inhibition experiments indicated that all tested influenza viruses were sensitive to oseltamivir and zanamivir.Some differences in HA and NA proteins were observed between the monitored strains and vaccine strains.Continued monitoring of the molecular evolution characteristics of influenza viruses is necessary to understand the risk of influenza outbreaks,and their effects on the effectiveness of influenza vaccines and therapeutic drugs.

Objective:To analyze the respiratory virus infection status and epidemiological characteristics of influenza-like illness (ILI) cases in Shandong Province during the 2020 -2021 influenza surveillance year. Methods:According to the National Influenza Surveillance Plan (2017 version), throat swab samples of ILI cases were collected from 14 surveillance sentinel hospitals in Shandong Province. Nucleic acid was extracted from all samples. Real-time fluorescence quantitative PCR (RT-PCR) was utilized to detect six common viruses, including human metapneumovirus (HMPV), human parainfluenza virus (HPIV) types 1, 2 and 3, respiratory syncytial virus (RSV), and adenovirus (ADV). Subsequently, the obtained detection results were analyzed.Results:A total of 2 386 specimens were collected, with a detection rate of 24.22% (578). Six viruses were detected, with detection rates of 6.75% (162 cases) for HMPV, 5.87% (140 cases) for RSV, 3.56% (85 cases) for HPIV3, 3.14% (75 cases) for HPIV2, 2.98% (71 cases) for HPIV1, and 2.77% (66 cases) for ADV. There was no significant difference in detection rates between genders, but a notable variation among different age groups ( P<0.001). The highest detection rate was observed in individuals aged 0-4 years (31.94%), followed by those aged≥60 years (26.06%). The prevalence of six viruses showed a monthly variation, with the detection rate of HMPV being higher in December and HPIV1 being higher in February. HPIV2, HPIV3, RSV, and ADV had higher detection rates in November. The co-detection rate of multiple viruses was 0.80%, with RSV being the most common pathogen involved in co-detection, primarily in individuals aged 0-4 years. Conclusion:The detection of six multiple pathogens in ILI cases in Shandong Province is dominated by HMPV, RSV and HPIV3. The prevalence of respiratory viruses varies by age and time.

This study investigated the epidemic status of H3N2 influenza virus and the genetic evolution characteristics of hemagglutinin(HA)and neuraminidase(NA)of H3N2 subtype influenza viruses isolated in Shandong Province during 2023-2024,to understand their compatibility with vaccine strains and drug resistance status.A total of 25 H3N2 subtype influenza virus strains were randomly selected from the strains isolated by the influenza surveillance network laboratory.The HA and NA genes were sequenced with the vaccine strains recommended by the WHO as a reference.Monitoring of sensitivity to oseltamivir and zanamivir was conducted through neuraminidase inhibition experiments.The H3N2 influenza viruses in Shandong Province belonged to the 3C.2a1b.2a.2a.3a.1 clade.Nucleotide sequence analysis revealed that the HA1 and NA genes were closely related to the WHO-recommended vaccine strain A/Darwin/9/2021 for the current season,with homology rates of 97.8%-98.2%and 98.9%-99.3%,respectively.Amino acid sequence analysis indicated 22 amino acid sequence variations in the HA1 protein,and antigenic drift was detected in 8 strains.A glycosylation site was added at position 94 of the HA protein in all 25 strains.Variations occurred in the NA antigenic determinants of some strains.Neuraminidase inhibition experiments indicated that all tested influenza viruses were sensitive to oseltamivir and zanamivir.Some differences in HA and NA proteins were observed between the monitored strains and vaccine strains.Continued monitoring of the molecular evolution characteristics of influenza viruses is necessary to understand the risk of influenza outbreaks,and their effects on the effectiveness of influenza vaccines and therapeutic drugs.

Objective:To analyze the epidemiological, etiological and genetic characteristics of influenza virus in Shandong Province during 2023-2024.Methods:The surveillance data of influenza-like illness (ILI) in sentinel hospitals in Shandong from 2023 to 2024 were collected and analyzed. The isolated influenza strains with hemagglutination titers ≥8 were selected for antigenicity analysis, drug susceptibility test, gene sequencing and evolutionary analysis.Results:From 2023 to 2024, the positive rate of influenza virus in Shandong was 8.51% (23 663/277 995), the highest positive rate was in the age group of 5-14 years (15.78%, 6 073/38 478), and the highest positive rate was in the 49 th week (35.86%, 2 264/6 313). Both antigenicity analysis and evolutionary analysis showed that the A(H1N1)pdm09 subtype and B(Victoria) strain had good matching effect and close evolutionary distance with the 2023-2024 surveillance year vaccine strain. The A(H3N2) subtype strain did not have a high matching effect with the 2023-2024 vaccine strain and had a long evolutionary distance, but had a close evolutionary distance with the 2024-2025 vaccine strain. Drug susceptibility test showed that oseltamivir sensitivity of influenza A(H1N1)pdm09 strain decreased greatly, and the amino acid site mutation of neuraminidase was H275Y. Conclusions:In the 2023-2024 surveillance year, the peak of influenza virus epidemic in Shandong was mainly occurred in winter and spring, and the age group of 5-14 years was the focus of prevention and control. The dominant strain was subtype A(H3N2), which had poor matching effect with the vaccine strain in the 2023-2024 surveillance year. One A(H1N1)pdm09 resistant strain was found in the drug resistance monitoring work. Follow-up prevention and control work should be strengthen the surveillance for the epidemiological characteristics, genetic variation and drug resistance of influenza viruses, timely understand the epidemic trend and mutation of influenza viruses, timely discover drug-resistant strains of influenza viruses, promote influenza vaccination, and improve of influenza prevention and control.

Objective:To analyze the respiratory virus infection status and epidemiological characteristics of influenza-like illness (ILI) cases in Shandong Province during the 2020 -2021 influenza surveillance year. Methods:According to the National Influenza Surveillance Plan (2017 version), throat swab samples of ILI cases were collected from 14 surveillance sentinel hospitals in Shandong Province. Nucleic acid was extracted from all samples. Real-time fluorescence quantitative PCR (RT-PCR) was utilized to detect six common viruses, including human metapneumovirus (HMPV), human parainfluenza virus (HPIV) types 1, 2 and 3, respiratory syncytial virus (RSV), and adenovirus (ADV). Subsequently, the obtained detection results were analyzed.Results:A total of 2 386 specimens were collected, with a detection rate of 24.22% (578). Six viruses were detected, with detection rates of 6.75% (162 cases) for HMPV, 5.87% (140 cases) for RSV, 3.56% (85 cases) for HPIV3, 3.14% (75 cases) for HPIV2, 2.98% (71 cases) for HPIV1, and 2.77% (66 cases) for ADV. There was no significant difference in detection rates between genders, but a notable variation among different age groups ( P<0.001). The highest detection rate was observed in individuals aged 0-4 years (31.94%), followed by those aged≥60 years (26.06%). The prevalence of six viruses showed a monthly variation, with the detection rate of HMPV being higher in December and HPIV1 being higher in February. HPIV2, HPIV3, RSV, and ADV had higher detection rates in November. The co-detection rate of multiple viruses was 0.80%, with RSV being the most common pathogen involved in co-detection, primarily in individuals aged 0-4 years. Conclusion:The detection of six multiple pathogens in ILI cases in Shandong Province is dominated by HMPV, RSV and HPIV3. The prevalence of respiratory viruses varies by age and time.

Objective:To investigate the incidence of mild cognitive impairment(MCI)and malnutrition among centenarians, as well as to explore the relationship between cognitive impairment and nutritional status.Methods:A cross-sectional study was conducted between November and December 2023, involving 121 elderly individuals aged ≥ 100 years in the Baoshan District of Shanghai.The survey collected general information and included the Ascertain Dementia 8-item Questionnaire(AD8), the Mini Nutritional Assessment Short-Form(MNA-SF), and anthropometric nutritional measurements such as waist circumference(WC), hip circumference(HC), arm circumference(AC), calf circumference(CC), and grip strength.The prevalence of MCI and malnutrition among centenarians was calculated, and the correlation between MCI and MNA-SF scores, along with anthropometric nutritional measurement indicators, was analyzed.Results:The age range of centenarians was between 100 and 105 years, with an average age of 101.0±3.5 years.The majority of centenarians were female(76.9%), illiterate(58.7%), and lived with family members(73.6%).All participants had medical insurance(100%).Most had no history of long-term smoking 118(97.5%), long-term alcohol consumption 108(89.3%), long-term use of health supplements 109(90.1%), long-term tea or coffee habits 114(94.2%), chronic medical conditions 84(69.4%), or family history of dementia 102(84.3%).Additionally, 62(51.2%)reported their health status over the past year as general.According to the AD8 screening results, the negative and positive detection rates of MCI in centenarians were 79(65.3%)and 47(34.7%), respectively.Based on the MNA-SF scoring results, the detection rates of normal nutrition, malnutrition risk, and malnutrition among centenarians were 36(29.8%), 61(50.4%), and 24(19.8%), respectively.There was a statistically significant difference in AC between the non-MCI group and the MCI group among centenarians( t=0.01, P=0.03).The AD8 scores of centenarians were significantly negatively correlated with AC, CC, and MNA-SF scores( r=-0.20, r=-0.26, r=-0.29; all P<0.05). Conclusions:The cognitive function of centenarians is associated with their nutritional status, indicating that higher cognitive abilities correlate with better nutritional status.

Objective:To analyze the epidemiological, etiological and genetic characteristics of influenza virus in Shandong Province during 2023-2024.Methods:The surveillance data of influenza-like illness (ILI) in sentinel hospitals in Shandong from 2023 to 2024 were collected and analyzed. The isolated influenza strains with hemagglutination titers ≥8 were selected for antigenicity analysis, drug susceptibility test, gene sequencing and evolutionary analysis.Results:From 2023 to 2024, the positive rate of influenza virus in Shandong was 8.51% (23 663/277 995), the highest positive rate was in the age group of 5-14 years (15.78%, 6 073/38 478), and the highest positive rate was in the 49 th week (35.86%, 2 264/6 313). Both antigenicity analysis and evolutionary analysis showed that the A(H1N1)pdm09 subtype and B(Victoria) strain had good matching effect and close evolutionary distance with the 2023-2024 surveillance year vaccine strain. The A(H3N2) subtype strain did not have a high matching effect with the 2023-2024 vaccine strain and had a long evolutionary distance, but had a close evolutionary distance with the 2024-2025 vaccine strain. Drug susceptibility test showed that oseltamivir sensitivity of influenza A(H1N1)pdm09 strain decreased greatly, and the amino acid site mutation of neuraminidase was H275Y. Conclusions:In the 2023-2024 surveillance year, the peak of influenza virus epidemic in Shandong was mainly occurred in winter and spring, and the age group of 5-14 years was the focus of prevention and control. The dominant strain was subtype A(H3N2), which had poor matching effect with the vaccine strain in the 2023-2024 surveillance year. One A(H1N1)pdm09 resistant strain was found in the drug resistance monitoring work. Follow-up prevention and control work should be strengthen the surveillance for the epidemiological characteristics, genetic variation and drug resistance of influenza viruses, timely understand the epidemic trend and mutation of influenza viruses, timely discover drug-resistant strains of influenza viruses, promote influenza vaccination, and improve of influenza prevention and control.

Objective:To investigate the incidence of mild cognitive impairment(MCI)and malnutrition among centenarians, as well as to explore the relationship between cognitive impairment and nutritional status.Methods:A cross-sectional study was conducted between November and December 2023, involving 121 elderly individuals aged ≥ 100 years in the Baoshan District of Shanghai.The survey collected general information and included the Ascertain Dementia 8-item Questionnaire(AD8), the Mini Nutritional Assessment Short-Form(MNA-SF), and anthropometric nutritional measurements such as waist circumference(WC), hip circumference(HC), arm circumference(AC), calf circumference(CC), and grip strength.The prevalence of MCI and malnutrition among centenarians was calculated, and the correlation between MCI and MNA-SF scores, along with anthropometric nutritional measurement indicators, was analyzed.Results:The age range of centenarians was between 100 and 105 years, with an average age of 101.0±3.5 years.The majority of centenarians were female(76.9%), illiterate(58.7%), and lived with family members(73.6%).All participants had medical insurance(100%).Most had no history of long-term smoking 118(97.5%), long-term alcohol consumption 108(89.3%), long-term use of health supplements 109(90.1%), long-term tea or coffee habits 114(94.2%), chronic medical conditions 84(69.4%), or family history of dementia 102(84.3%).Additionally, 62(51.2%)reported their health status over the past year as general.According to the AD8 screening results, the negative and positive detection rates of MCI in centenarians were 79(65.3%)and 47(34.7%), respectively.Based on the MNA-SF scoring results, the detection rates of normal nutrition, malnutrition risk, and malnutrition among centenarians were 36(29.8%), 61(50.4%), and 24(19.8%), respectively.There was a statistically significant difference in AC between the non-MCI group and the MCI group among centenarians( t=0.01, P=0.03).The AD8 scores of centenarians were significantly negatively correlated with AC, CC, and MNA-SF scores( r=-0.20, r=-0.26, r=-0.29; all P<0.05). Conclusions:The cognitive function of centenarians is associated with their nutritional status, indicating that higher cognitive abilities correlate with better nutritional status.

This study was aimed at characterizing the variations in hemagglutinin(HA)and neuraminidase(NA)genes of influenza virus subtype A(H1N1)pdm09 isolated during the 2022-2023 influenza monitoring year in Shandong Province,to provide a scientific basis for influenza prevention and control.A total of 14 A(H1N1)pdm09 subtype influenza strains were se-lected randomly by city by the influenza monitoring network laboratory.The vaccine strains recommended by the WHO served as references for whole gene sequencing analysis.A fluorescence method was used to conduct neuraminidase inhibition experi-ments to evaluate drug sensitivity.The A(H1N1)pdm09 influenza virus in Shandong Province,2022-2023 belonged to the 5a.2a evolutionary cluster in the 6B.1A branch.Nucleotide sequence analysis indicated that the HA and NA genes were closely re-lated to the Northern Hemisphere vaccine strain A/Victoria/2570/2019 in the years 2021-2023,and showed homology of 98.5％to 98.7％and 98.8％to 99.1％,respectively.Amino acid sequence analysis revealed 20 amino acid sequence mutations in the HA protein,but only one virus strain was found to have antigen drift,and three virus strains showed loss of HA protein glycosylation sites.No mutations were found at important sites affecting NA enzymes.The neuraminidase inhibition experiment indicated viral sensitivity to anti-influenza drugs.In conclusion,the monitored virus strains had high overall homology with vac-cine strains but showed some amino acid variation.In the future,continued monitoring of the genetic variation characteristics of influenza viruses will be necessary to understand the risk of influenza epidemics,and the effectiveness of influenza vaccines and therapeutic drugs.

This study was aimed at understanding the pollution distribution pattern of avian influenza virus in the environ-ment in poultry related places in Shandong Province,to provide a scientific basis for the prevention,control,prediction,and early warning regarding human infection with avian influenza.From 2020 to 2023,6 523 environmental samples were collected in 16 cities in Shandong Province from four types of poultry-related places.Fluorescence quantitative PCR was used for nucleic acid testing of influenza A virus.Positive samples were further identified for the H5,H7,and H9 subtypes of avian influenza virus.The epidemiological characteristics of avian influenza viruses in the poultry related environment of Shandong Province were described,and inter-rate comparisons were performed with the x2 test.During 2020-2023,6 523 environmental samples were collected,and 1 007 cases positive for avian influenza virus were detected,with a positivity rate of 15.44％.H5,H7,and H9 subtypesand mixed infections were detected.H9 was the main subtype(88.48％)in positive specimens.A significant difference in positivity rates was observed among regions(x2=431.956,P＜0.001),and the highest positivity rate was 28.93％.Significant differences in positivity rates were observed among monitoring sites(x2=304.604,P＜0.001),sample types(x2=109.678,P＜0.001),and quarters(x2=64.963,P＜0.001).The positive detection rate was highest at monitoring sites in urban and rural live poultry markets(20.12％),and the positive detection rate of samples collected by wiping meat cut-ting board surfaces was higher than that of other samples(22.56％).The peak positive detection rate occurred in spring(20.31％).Widespread contamination with avian influenza virus was observed in poultry environments in Shandong Prov-ince.The H9 subtype,the main pathogen,coexisted with H5 and H7 subtypes,thus posing a risk of human infection with avian influenza.Therefore,prevention and control of avian influenza must be strengthened in key seasons,areas,places,and links.