Objective: To investigate the spatio-temporal clustering characteristics of influenza in Shaoxing City, Zhejiang Province from 2015 to 2024, so as to provide the basis for formulating influenza prevention and control strategies. Methods: Influenza case data in Shaoxing City from 2015 to 2024 were collected through the Infectious Disease Surveillance Reporting System of the Chinese Disease Prevention and Control Information System. Descriptive epidemiological methods analyses were used to analyze the epidemiological characteristics of influenza. Spatial autocorrelation and spatio-temporal scanning were used to analyze the spatio-temporal clustering characteristics of influenza. Results: A total of 328 759 influenza cases were reported in Shaoxing City from 2015 to 2024, with an average annual reported incidence of 639.90/100 000, which showed an upward trend (AAPC=68.95%, P<0.05). The peak incidence period was from December to February of the following year, with 193 051 cases reported, accounting for 58.72%. There were 165 408 male cases and 163 351 female cases, with a male-to-female ratio of 1.01∶1. Children and adolescents aged 0-<15 years constituted the high-incidence population, while students represented the predominant occupational category, comprising 113 589 cases (34.55%). Keqiao District, Shengzhou City, and Yuecheng District had the top three average annual reported incidence of influenza, at 995.64/100 000, 734.66/100 000, and 687.44/100 000, respectively. Spatial autocorrelation analysis showed that, there were 155 high-high aggregation areas in Shaoxing City from 2015 to 2024, which gradually expanded from the local aggregation in the central part of Shengzhou City to Keqiao District and then spread to Yuecheng District. Spatio-temporal scanning analysis showed that, from November 2023 to February 2024, the strongest spatio-temporal clustering of influenza centered on Keqiao Street in Keqiao District, covering 11 towns (streets) in Yuecheng District and Keqiao District. From 2015 to 2018, the primary-type clustering of influenza was mainly concentrated in Xinchang County and Shengzhou City. After 2019, they gradually shifted to Yuecheng District and Keqiao District, with the main clustering period being from November to February of the following year. Conclusions The incidence of influenza in Shaoxing City from 2015 to 2024 showed an upward trend, with obvious spatio-temporal clustering. The clustering area expanded from Shengzhou City in the central region to Keqiao District and Yuecheng District in the northern region, mainly clustering from November to February of the following year.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.

Objective To understand the changing distribution and antimicrobial resistance profiles of Klebsiella strains in 52 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Antimicrobial susceptibility testing was carried out according to the unified CHINET protocol.The susceptibility results were interpreted according to the breakpoints in the Clinical & Laboratory Standards Institute(CLSI)M100 document.Results A total of 241,549 nonduplicate Klebsiella strains were isolated from 2015 to 2021,including Klebsiella pneumoniae(88.0％),Klebsiella aerogenes(5.8％),Klebsiella oxytoca(5.7％),and other Klebsiella species(0.6％).Klebsiella strains were mainly isolated from respiratory tract(48.49±5.32)％.Internal medicine(22.79±3.28)％,surgery(17.98±3.10)％,and ICU(14.03±1.39)％were the top 3 departments where Klebsiella strains were most frequently isolated.K.pneumoniae isolates showed higher resistance rate to most antimicrobial agents compared to other Klebsiella species.Klebsiella isolates maintained low resistance rates to tigecycline and polymyxin B.ESBLs-producing K.pneumoniae and K.oxytoca strains showed higher resistance rates to all the antimicrobial agents tested compared to the corresponding ESBLs-nonproducing strains.The K.pneumoniae and carbapenem-resistant K.pneumoniae(CRKP)strains isolated from ICU patients demonstrated higher resistance rates to majority of the antimicrobial agents tested than the strains isolated from non-ICU patients.The CRKP strains isolated from adult patients had higher resistance rates to most of the antimicrobial agents tested than the corresponding CRKP strains isolated from paediatric patients.Conclusions The prevalence of carbapenem-resistant strains in Klebsiella isolates increased greatly from 2015 to 2021.However,the Klebsiella isolates remained highly susceptible to tigecycline and polymyxin B.Antimicrobial resistance surveillance should still be strengthened for Klebsiella strains.

Objective To investigate the changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.

Objective: To analyze epidemiological characteristics of brucellosis in Shaoxing City, Zhejiang Province from 2005 to 2023, so as to provide the basis for developing targeted control measures. Methods: Data of brucellosis cases and epidemiological investigation in Shaoxing City from 2005 to 2023 were collected from the Monitoring and Reporting Management System of the Chinese Disease Prevention and Control Information System. The epidemiological characteristics of brucellosis were descriptively analyzed, the trend in incidence of brucellosis was analyzed using average annual percent change (AAPC). Results: A total of 270 cases of brucellosis were reported in Shaoxing City from 2005 to 2023, with an average annual incidence of 0.29/105. The AAPC was 0.812%, with no significant changing trend (P>0.05). The incidence of brucellosis peaked from February to March, with 80 cases (29.63%). The reported cases were mainly distributed in Shangyu District (139 cases, 51.48%) and Shengzhou City (74 cases, 27.41%). There were 188 male cases and 82 female cases, with a male-to-female ratio of 2.29∶1. The cases were primarily concentrated in the age group of 40 to <70 years, with 205 cases accounting for 75.93%. Among these, 86 cases were reported in the 50 to <60 years of age group, accounting for 41.95%. The majority of the cases were farmers, with 187 cases accounting for 69.26%. The median interval from onset to diagnosis was 22.73 (interquartile range, 39.97) days, with a delayed diagnosis rate of 62.96%. Infections through breeding, selling and transporting cattle and sheep resulted in 164 cases (60.74%), and through buying and slaughtering resulted in 36 cases (13.33%). An outbreak of brucellosis was reported in Xinchang County in 2018, with three confirmed cases. Conclusions The incidence of brucellosis in Shaoxing City had no significant change from 2005 to 2023. The peak period was from February to March. The cases were mainly distributed in Shangyu District and Shengzhou City. People aged 50 to <60 years, males, and farmers were the key groups for prevention and control.

Objective: To analyze the prevalence and related factors of pediatric flexible flatfoot (PFF) among 7-8 year old children in Changzhou, so as to provide a feasible basis for the prevention and treatment of PFF. Methods: From December 2023 to February 2024, a total of 1 685 children aged 7-8 from 10 primary schools in Changzhou were selected by stratified cluster random sampling method, and screened for PFF by using a foot optical assessment recording device. Information including sex, body mass index (BMI), diet, exercise and shoe wearing habits were collected. The valgus angle of the hindfoot was measured on the body surface by using an orthopedic measuring ruler in the standing position. Pain levels were evaluated by using visual analogue score (VAS) for children with flatfoot syndrome. Multivariate Logistic analysis was used to analyze related factors of PFF. Results: The overall detection rate of PFF was 27.4%, and there was a significant difference in the detection rate of PFF between boys and girls, with 30.3% and 24.1% respectively ( χ 2=7.96, P < 0.01 ). Most cases of PFF were mild flatfoot (60.8%) and bilateral ( 60.4% ). Approximately 13.2% of children with PFF had flatfoot syndrome, with a mean VAS of (2.86±0.73). About 56.1% of children with PFF had a normal valgus angle of the hindfoot. Sex, high BMI and preference for shoe last with front upturned shoe shape were positively correlated with the detection of PFF ( OR= 1.74, 1.54, 1.13, P <0.05). After stratified by sex, regular exercise in boys and age in girls were negatively correlated with the detection of PFF ( OR=0.40, 0.64, P <0.05). Conclusions The detection rate of PFF in 7-8 year old children is high. Additionally, PFF combined with flatfoot syndrome or valgus hindfoot is relatively rare and is likely to be underestimated, which emphasizes the importance of early detection and intervention for PFF.

Objective: To prepare an inactivated hepatitis A vaccine using a attenuated strain of hepatitis A virus (HAV) H2 and to analyze its immunizing dose, so as to provide the reference for development and production of inactivated hepatitis A vaccines. Methods: Human embryonic lung diploid cells (KMB17) were infected with attenuated HAV H2 strain to proliferate the virus, then the cells containing viruses were harvested, extracted and purified. The obtained virus concentrate was prepared into vaccine bulk and test vaccines with 1 280 EU/mL antigen content. Vaccine testing was carried out according to the inactivated hepatitis A vaccine standards specified in the Part Ⅲ of the Pharmacopoeia of the People's Republic of China (2020 edition). A total of 110 mice were randomly divided into 11 groups, including 5 dose groups (80, 160, 320, 640 and 1 280 EU/dose) of the test vaccine and the reference vaccine, as well as the adjuvant control group. Mice were immunized twice by intraperitoneal injection, their serum HAV antibodies were detected, and the geometric mean titer (GMT) and positive conversion rate of antibodies were analyzed to evaluate the immunising dose of the vaccine. Results: The antigen content and viral titer of the virus harvest solution were 5 120 EU/mL and 8.33 lgCCID50/mL, respectively. The removal rate of foreign protein reached 98.05% and the recovery rate of antigen was 66.25%. The test vaccine met the requirements of Part Ⅲ of the Pharmacopoeia of the People's Republic of China (2020 edition). The GMTs of HAV antibodies in the test vaccine and the reference vaccine dose groups after the second immunization were more than twice higher than those after the first immunization. Regardless of primary immunization or secondary immunization, the GMTs (log2) of HAV antibodies in the test vaccine groups with doses of 160 EU/dose and above were higher than those in the 80 EU/dose group (all P<0.05), while there was no statistically significant differences between the dose groups of 160 EU/dose and above (all P>0.05). The antibody positive conversion rate of 160 EU/dose and above of the test vaccine was 100.00% after the secondary immunization. Conclusions The inactivated hepatitis A vaccine of attenuated H2 strain tested in this study demonstrates strong immunogenicity in mice, suggesting its potential as a candidate vaccine. The preliminary analysis indicates an immunizing dose of 320 EU/dose for children and 640 EU/dose for adults.