Objective:To compare the etiological characteristics between influenza-like illness (ILI) cases in outpatient and emergency departments and those with severe acute respiratory infection (SARI) in Guangdong Province, hoping to provide scientific evidence for the treatment, prevention, and control of respiratory infectious diseases.Methods:Laboratory testing for multiple respiratory pathogens was conducted on 6 090 specimens collected from ILI and SARI cases in Guangdong Province from August to December 2023. Chi-square test was used to analyze the differences in positive rates. Results:The overall positive rate of respiratory pathogens was 49.5% (3 016/6 090). The positive rate was 54.5% (2 260/4 145) in ILI cases and 38.9% (756/1 945) in SARI cases. The overall positive rate was higher in ILI cases than in SARI cases across all genders and age groups, and in most cities of the province, with statistically significant differences ( P<0.05). No significant difference was found in the overall positive rate between different genders. However, the difference between different age groups was statistically significant( P<0.001), with the highest rate identified in children aged 5-14 years (57.2%, 957/1 673). The main pathogens detected in ILI cases were influenza virus, human rhinovirus/enterovirus, and Streptococcus pneumoniae, while in SARI cases they were Mycoplasma pneumoniae, human rhinovirus/enterovirus, and influenza virus. The positive rates of adenovirus, human parainfluenza virus, SARS-CoV-2, human coronavirus, influenza virus, and Streptococcus pneumoniae were significantly higher in ILI cases than in SARI cases, while the positive rate of Mycoplasma pneumoniae was significantly higher in SARI cases ( P<0.05). Moreover, ILI cases were characterized by a higher risk of coinfection compared with SARI cases, especially in males or those aged 25-59 years. Conclusions:There are differences in the detection rates and spectrum of respiratory pathogens between ILI and SARI cases in Guangdong Province. Case features should be considered when developing strategies for preventing and treating respiratory infections.

Objective To investigate the carrying status and drug resistance analysis of pathogenic bacteria in the gut of healthy population in Huadu District,Guangzhou,and provide reference for epidemiological re-search.Methods A total of 337 459 anal swabs were directly isolated and cultured from healthy individuals who underwent physical examinations from 2018 to 2023.600 anal swabs from 2022 were randomly selected for multi pathogen nucleic acid testing,direct isolation and culture,and enrichment culture.Identification of bacteria was conducted by using VITEK 2 Compact and VITEK MS,serological testing was used for determi-nation of type,and drug susceptibility testing of pathogenic bacteria was conducted.Results A total of 128 pathogenic bacteria were isolated from rectal swabs,including 52 strains of Salmonella,71 strains of Aero-monas,3 strains of Vibrio parahaemolyticus,and 2 strains of Shigella flexneri,with a total detection rate of 3.79/10 000.The detection rate of Salmonella in direct isolation and culture of 600 rectal swabs was 0.50％,the detection rate of enrichment culture was 1.00％,and the detection rate of multi-pathogen nucleic acid de-tection was 1.17％.52 strains of Salmonella were divided into 27 serotypes,and Salmonella Ⅰ 4,5,12:i:—was the dominant serotype.Aeromonas sobria was the dominant serotype in Aeromonas.The sensitivity of Salmonella to piperacillin/tazobactam,imipenem,cefepime,levofloxacin,and aztreonam was up to 92.00％or more,however,the phenomenon of multidrug resistance was severe,with a multidrug resistance rate as high as 40.38％.The resistance rate of Aeromonas to ampicillin and ampicillin/sulbactam was up to 85.00％or more,while Aeromonas was relatively sensitive to other antibiotics.Conclusion There are many species and types of intestinal pathogenic bacteria carried by healthy individuals in Huadu District,Guangzhou,with Aero-monas and Salmonella ranking first and second,and levofloxacin treatment could be preferred.The use of bac-terial culture and multi pathogen nucleic acid testing methods could improve the detection rate of intestinal pathogenic bacteria,and attention should be paid to the monitoring of intestinal pathogenic bacteria among rel-evant practitioners.

For rare real-world data involving off-label drug use or comorbidity-associated polypharmacy,researchers have increasingly adopted target trial emulation to investigate drug repurposing for target indications.The success of such studies hinges on rigorous trial design and strict adherence to predefined protocols and standardized pipelines.Key elements in the trial design include the precise definition of inclusion and exclusion criteria,the selection of trial and control drugs and determination of treatment allocation time,the determination of appropriate efficacy endpoints for the target indication,the identification of causal estimands,and the development of robust strategies for confounding adjustment.The execution of the trial follows a structured process:screening eligible subjects,extracting relevant drug exposure data,constructing treatment and control groups,emulating the target trial,and ultimately generating hypotheses for drug repurposing through statistical inference.Propensity score methods,including stratification,matching and weighting techniques,are critical tools for addressing confounding bias and ensuring accurate estimation of causal effects.In recent years,creative progress has been made in target trial emulation,particularly in the calculation of propensity scores.Researchers have adopted advanced machine learning techniques,to enhance variable selection and have actively explored the use of innovative methods of digital intelligence technology like classification and regression trees,support vector machines,and deep learning for the application of propensity score calculation.Target trial emulation based on real-world data has achieved remarkable advancements in drug repurposing,demonstrating broad application prospects,particularly in cardiovascular diseases,metabolic disorders,Alzheimer's disease,and cancer.

For rare real-world data involving off-label drug use or comorbidity-associated polypharmacy,researchers have increasingly adopted target trial emulation to investigate drug repurposing for target indications.The success of such studies hinges on rigorous trial design and strict adherence to predefined protocols and standardized pipelines.Key elements in the trial design include the precise definition of inclusion and exclusion criteria,the selection of trial and control drugs and determination of treatment allocation time,the determination of appropriate efficacy endpoints for the target indication,the identification of causal estimands,and the development of robust strategies for confounding adjustment.The execution of the trial follows a structured process:screening eligible subjects,extracting relevant drug exposure data,constructing treatment and control groups,emulating the target trial,and ultimately generating hypotheses for drug repurposing through statistical inference.Propensity score methods,including stratification,matching and weighting techniques,are critical tools for addressing confounding bias and ensuring accurate estimation of causal effects.In recent years,creative progress has been made in target trial emulation,particularly in the calculation of propensity scores.Researchers have adopted advanced machine learning techniques,to enhance variable selection and have actively explored the use of innovative methods of digital intelligence technology like classification and regression trees,support vector machines,and deep learning for the application of propensity score calculation.Target trial emulation based on real-world data has achieved remarkable advancements in drug repurposing,demonstrating broad application prospects,particularly in cardiovascular diseases,metabolic disorders,Alzheimer's disease,and cancer.

Objective:To compare the etiological characteristics between influenza-like illness (ILI) cases in outpatient and emergency departments and those with severe acute respiratory infection (SARI) in Guangdong Province, hoping to provide scientific evidence for the treatment, prevention, and control of respiratory infectious diseases.Methods:Laboratory testing for multiple respiratory pathogens was conducted on 6 090 specimens collected from ILI and SARI cases in Guangdong Province from August to December 2023. Chi-square test was used to analyze the differences in positive rates. Results:The overall positive rate of respiratory pathogens was 49.5% (3 016/6 090). The positive rate was 54.5% (2 260/4 145) in ILI cases and 38.9% (756/1 945) in SARI cases. The overall positive rate was higher in ILI cases than in SARI cases across all genders and age groups, and in most cities of the province, with statistically significant differences ( P<0.05). No significant difference was found in the overall positive rate between different genders. However, the difference between different age groups was statistically significant( P<0.001), with the highest rate identified in children aged 5-14 years (57.2%, 957/1 673). The main pathogens detected in ILI cases were influenza virus, human rhinovirus/enterovirus, and Streptococcus pneumoniae, while in SARI cases they were Mycoplasma pneumoniae, human rhinovirus/enterovirus, and influenza virus. The positive rates of adenovirus, human parainfluenza virus, SARS-CoV-2, human coronavirus, influenza virus, and Streptococcus pneumoniae were significantly higher in ILI cases than in SARI cases, while the positive rate of Mycoplasma pneumoniae was significantly higher in SARI cases ( P<0.05). Moreover, ILI cases were characterized by a higher risk of coinfection compared with SARI cases, especially in males or those aged 25-59 years. Conclusions:There are differences in the detection rates and spectrum of respiratory pathogens between ILI and SARI cases in Guangdong Province. Case features should be considered when developing strategies for preventing and treating respiratory infections.

Objective To translate the Inflammatory Bowel Disease Disability Visual Analogue Scale (IBD Disk) into Chinese and conduct cross-cultural adaptation, and to test its reliability and validity among patients with inflammatory bowel disease (IBD). Methods Based on the modified Brislin translation model, the IBD Disk was translated into Chinese through forward translation, back translation, group discussion, and cross-cultural adaptation. From January to December 2022, a convenience sampling method was used to select 299 IBD patients for investigation to verify the reliability and validity of the Scale. Results The Chinese version of the IBD Disk includes 10 items, with decision values of 4.79 to 15.68 (>3.00), and P value was less than 0.05, indicating high discriminatory power for each item; the total Cronbach's α coefficient of the scale was 0.88, and the test-retest reliability was 0.87, indicating a good reproducibility of the scale; confirmatory factor analysis results indicated that the scale had ideal fit; Pearson correlation analysis results indicated that the total score of the IBD Disk was significantly positively correlated with the total score of the Inflammatory Bowel Disease Disability Index Scale (IBD-DI) (r=0.81, P < 0.001), suggesting good correlation between the IBD Disk and the IBD-DI. Conclusion The Chinese version of the IBD Disk has good reliability and validity, and is suitable to be used as a disability assessment tool for IBD patients in Chinese culture.

Objective:To study the epidemiological and genetic characteristics of coxsackievirus B3 (CVB3) circulating in Guangdong Province from 2008 to 2021.Methods:This study collected the specimens of hand, foot, and mouth disease (HFMD) cases from 2008 to 2021 that were positive for other enteroviruses except for enterovirus 71 (EV71), coxsackievirus A16 (CVA16), and CVA6, as well as the specimens of herpangina and neonatal infection cases from 2020 to 2021. Enteroviruses in these specimens were detected and their types were identified. CVB3 strains were isolated and the entire VP1 sequences of CVB3 strains were amplified and sequenced. The genetic features of CVB3 strains were analyzed using DNAStar 7.1 and MEGA 6.06 software packages.Results:Among 3 484 HFMD cases positive for other enteroviruses from 2008 to 2021, CVB3-positive cases accounted for 1.6% (57/3 484); among 560 cases of herpangina from 2020 to 2021, CVB3-positive cases accounted for 2.1% (12/560); one neonatal infection case in 2021 was positive for CVB3. CVB3-positive cases accounted for 67.1% (47/70) in 2021 and 18.6% (13/70) in 2020, while there were less than five cases in other years. Forty-eight CVB3 strains were isolated and the entire VP1 sequences of 26 CVB3 strains were obtained. Phylogenetic analysis indicated that the CVB3 strains could be divided into eight genotypes (A-H) and the strains of genotypes A, D and E were prevalent in the Chinese mainland. The 26 CVB3 strains isolated in Guangdong Province shared 80.2%-100.0% nucleotide homology, and belonged to two genotypes of D and E, with genotype D prevalent from 2008 to 2017 and genotype E prevalent from 2020 to 2021.Conclusions:CVB3 is prevalent sporadically in Guangdong Province from 2008 to 2017, but the epidemic intensity increased during 2020 and 2021. CVB3 strains of genotypes D and E are prevalent in Guangdong Province during 2008 to 2021, with genotype E being the prevalent genotype during 2020 and 2021.

Objective:To analyze and reveal the genetic evolution and variation of influenza viruses in cases of co-infection in Guangdong Province.Methods:Throat swab samples were collected from four cases of H1N1pdm and H3N2 co-infection for viral isolation. The isolated strains were subjected to antigen analysis and neuraminidase inhibitor susceptibility test. High-throughput sequencing was used to detect the sequences of strains in three throat swab samples and one virus strain, and then genetic variations were analyzed.Results:Four influenza viruses were isolated with one strain of H1N1pdm and three of H3N2 subtype, and all of them were genetically similar to the vaccine strain in 2022-2023. The HA genes of H1N1pdm and H3N2 strains belonged to clade 6B.1A.5a.2a and 2a.3a.1, respectively. The isolated strains belonged to the same clade as the strains prevalent in Guangdong during the same period. No drug-resistant variations were detected in N1 or N2 gene, and the isolated strains were sensitive to oseltamivir and zanamivir.Conclusions:H1pdm subtype had stronger replication ability than H3 subtype in the influenza viruses isolated from co-infected cases. H1N1pdm and H3N2 subtype influenza viruses were genetically similar to the strains circulating in Guangdong at the same time. The isolated H1N1pdm and H3N2 strains were sensitive to both oseltamivir and zanamivir, indicating that they could continue to be used in the treatment of influenza virus infections caused by one or two genotypes.

Objective:To analyze the evolutionary characteristics and variation of etiological agent in an acute hemorrhagic conjunctivitis (AHC) outbreak in a city of Guangdong province in May, so as to provide scientific basis for formulating a new round of measures for prevention and control of AHC epidemic.Methods:In this study, 20 conjunctival swabs were collected from AHC patients, and enterovirus, human enterovirus 70 (HEV70) and coxsackievirus A 24 variant (CVA24v) nucleic acids were detected by real-time fluorescence quantitative PCR. In addition, the VP1 and 3Cpro regions of the CVA24v positive samples were sequenced to analyze their evolutionary relationship with the CVA24v strains circulating in China and abroad.Results:All the 20 eye swab samples were EV-positive, and CVA24v-positive, with a positive rate of 100.00%, and all were HEV70-negative.The genomes of CVA24v in VP1 and 3Cpro regions of CVA24v in 5 and 7 samples were successfully sequenced. Based on molecular characterization analysis of VP1 and 3Cpro regions, it was found that the CVA24v isolated in this outbreak had the greatest nucleotide similarity with the CVA24v strains isolated in Thailand in 2014 and French Reunion Islands in 2015. The phylogenetic analysis of 3Cpro and VP1 regions showed that the CVA24v isolated in this outbreak is clustered together with the CVA24v that was prevalent in Thailand in 2014 and the French Reunion Islands in 2015, and have high affinity. Compared with CVA24v isolated in Guangdong in 2010, Thailand in 2014, and French Reunion Islands in 2015, CVA24v isolated in this outbreak was replaced at 4 amino acid sites in 3Cpro region and 1 amino acid site in VP1 region.Conclusions:The cause of this outbreak is enterovirus CVA24v, which has the highest similarity to CVA24v isolated in Thailand in 2014 and in the French Reunion Islands in 2015. There were new amino acid mutations in both 3Cpro and VP1 regions.

Objective:To obtain the genome sequences of SARS-CoV-2 in respiratory specimens in Guangdong Province with next-generation sequencing (NGS) and analyze the factors influencing sequencing.Methods:Eight upper and lower respiratory tract specimens were collected from patients with SARS-CoV-2 infection in Guangdong Province in January 2020. RNA library construction was used to obtain the genome sequences of SARS-CoV-2. A bio-informatics software package (CLC Genomics Workbench 12.0) was used to analyze and compare the genomic sequences.Results:Five SARS-CoV-2 genome sequences were obtained from the eight specimens and two were obtained from lower respiratory tract specimens. The nucleotide homology to SARS-CoV-2 was 97.74%-99.90%. The Ct values were lower, while the sequencing depth, coverage, relative abundance and genome integrity were higher in sequencing the SARS-CoV-2 in lower respiratory tract specimens.Conclusions:The low Ct value of SARS-CoV-2 in the samples was good for sequencing.