Objective To evaluate the viral composition in respiratory samples from hospitalized children with acute respiratory infections in Yancheng，Jiangsu province，between January 2024 and June 2025 using metagenomic next-generation sequencing（mNGS）.Methods:A total of 247 respiratory specimens，including throat swabs，sputum，and bronchoalveolar lavage fluid，were collected from 247 hospitalized children in Yancheng，Jiangsu province，during the study period. The viral composition in these samples was detected and analyzed using mNGS technology.Results:Among the 247 cases，there were 136 cases of pneumonia（including 4 cases of severe pneumonia），45 cases of bronchopneumonia，27 cases of upper respiratory tract infection，and 39 cases of bronchitis. The ages of the patients ranged from 41 days to 14 years，with a median age of 3 years. High-throughput sequencing results showed that the positive detection rate for viruses in the respiratory samples was 89.88%（222/247），The detection rate of viruses causing respiratory tract infections was 69.23%（171/247），With RNA viruses detected in 71.65%（177/247）of the cases and DNA viruses in 43.32%（107/247）. The top three viruses detected were rhinovirus（24.29%，60/247），human herpesvirus 7（HHV-7）（21.86%，54/247），and influenza A H1N1（20.24%，50/247）. The common detected viruses that cause respiratory infections are rhinovirus（24.29%），influenza A virus H1N1（20.24%），RSV（17.81%），metapneumovirus（10.53%），enterovirus（6.88%），parainfluenza virus（6.07%），bocavirus（6.07%），coronavirus（2.43%），and adenovirus（2.43%）. In children with pneumonia，the top two respiratory viruses detected were rhinovirus（19.85%，27/136）and influenza A H1N1（16.91%，23/136）. In children with bronchopneumonia，the main viruses detected were rhinovirus（31.11%，14/45）and respiratory syncytial virus（24.44%，11/45）. In children with upper respiratory tract infections，the main viruses detected were influenza A H1N1（33.33%，9/27）and rhinovirus（25.93%，7/27）. In children with bronchitis，the main viruses detected were rhinovirus（30.77%，12/39）and respiratory syncytial virus（25.64%，10/39）. Among the 4 cases of severe pneumonia，the viruses detected were influenza A H1N1（2/4），respiratory syncytial virus（1/4），and bocavirus（1/4）.Conclusion:mNGS analysis revealed a high positive detection rate of respiratory viruses（89.88%）in hospitalized children with acute respiratory infections in Yancheng，Jiangsu，from January 2024 to June 2025，with influenza A H1N1 and rhinovirus being the most predominant.

Objective:To analyze the epidemiological characteristics of rabies in China during 2024 to understand the patterns of disease transmission and provide a scientific basis for optimizing prevention strategies and advancing the rabies elimination process.Methods:Data on the national rabies epidemic in 2024 and case-specific information from national surveillance sites were collected from China's National Notifiable Disease Reporting System（NNDRS）. Descriptive epidemiological methods were used to analyze the disease trends and epidemic characteristics.Results:In 2024，China reported 167 human rabies cases across 20 provincial-level administrative divisions（PLADs），resulting in 148 fatalities. This represents a 39.17% increase from 2023（120 cases）and the highest annual incidence recorded since 2019. The epidemic exhibited a distinct geographic clustering in central and southern China，with four provinces（Henan，Guangxi，Hunan，and Hubei）accounting for 62.87%（105/167）of nationally reported cases. October（20 cases）and November（20 cases）recorded the highest monthly incidence，while February had the lowest（2 cases）. Farmers constituted the primary affected demographic（80.84%），with a marked male predominance（male-to-female ratio：2.15∶1）-higher than the 2023 ratio（1.86∶1）. Cases spanned all age groups，predominantly affecting middle-aged and older adults. Analysis of 54 cases revealed dogs as the primary exposure source（93.88%），with domestic dogs constituting 75.00% of these.The laboratory diagnosis rate of rabies cases in 2024 was 43.71%（73/167）.Conclusion:After 16 consecutive years of decline，China's rabies epidemic rebounded in 2024，primarily driven by deficiencies in domestic dog management and weaknesses in post-exposure prophylaxis. Key recommendations include enhancing canine vaccination coverage in high-risk areas，implementing targeted health education for farmers and middle-aged and older adults，improving standardized post-exposure treatment protocols，and optimizing integrated surveillance-alert-response systems，ultimately advancing the achievement of rabies elimination goals.

Objective:To prepare a monoclonal strain of mumps virus of genotype F，which is intended to be applied as a national standard strain，and to provide corresponding virus strain resources for the surveillance，prevention and control of mumps.Methods:The plaque purification technique was used to pick monoclonal strains on Vero/hSLAM cells. The biological characteristics and stability of the monoclonal virus strains were evaluated by observing the cytopathic effect of the monoclonal virus strains，morphological observation of virological characteristics，determination of virus titer and whole-genome sequencing，and mycoplasma detection.Results:After infection of Vero/hSLAM cells，the monoclonal strain of mumps virus constructed after plaque purification could cause cell fusion. Under the negative staining electron microscope，the virus particles were spherical，with a diameter between 100 and 200 nm，and had an obvious envelope. The virus titer of the 2 nd to 6 th generations was between 10 6 and 10 7 TCID 50/ml. Through whole-genome sequencing and phylogenetic analysis，the full length of the virus genome sequence was obtained as 15 384 bp，and it was confirmed that the monoclonal virus strain was of genotype F. The nucleotide difference rate between the 2 nd and 6 th generations was 0.013%. Conclusion:The monoclonal strain of mumps virus constructed in this experiment has typical cytopathic effects and typical morphological structures. The virus has good activity and stable genetic characteristics，and can be used as a candidate strain for application as a national standard strain. It can be used for reagent research and development，evaluation of immunization effects，and other subsequent work.

Objective:To characterize the etiological and genetic features of pediatric influenza outbreaks in Changzhou between 2021 and 2024，with the goal of informing evidence-based prevention strategies and guiding effective management of influenza outbreaks in school settings.Methods:During the period of 2021 to 2024，throat swabs of influenza-like cases from school outbreaks in Changzhou were collected. These samples underwent real-time reverse transcription-polymerase chain reaction（RT-PCR）testing and virus isolation. Epidemiological data were integrated to conduct pathogenetic analysis. The HA genes of isolated strains were amplified and sequenced to perform genetic characterization.Results:Between 2021 and 2024，a total of 256 influenza outbreaks were reported in schools in Changzhou. A total of 3 201 specimens were collected，of which 2 245 were tested positive for influenza viruses，resulting in a positivity rate of 70.13%. The outbreak season was primarily concentrated from December to February each year，with settings predominantly distributed in primary schools（accounting for 73.83%）. The predominant epidemic strains were influenza A viruses，including 118 outbreaks caused by H1N1 and 104 by H3N2. A total of 74 influenza virus strains were successfully isolated from positive specimens，and sequencing of the hemagglutinin（HA）gene was completed. Phylogenetic analysis revealed that certain B/Victoria lineage strains（e.g.，B/Changzhou/01/2021）clustered closely with the vaccine strain B/Austria/3594/17（bootstrap support：99%）. Among influenza H1N1 strains，multiple isolates from 2023—2024 clustered within the same major branch as A/Victoria/4897/2022（bootstrap support：100%）. In contrast，the H3N2 strains exhibited a complex evolutionary pattern，showing variable genetic distances to vaccine strains from different years（e.g.，A/Massachusetts/18/2022，A/Darwin/6/2021）；some isolates were closely related to vaccine strains，while others were more distantly related and scattered across the phylogenetic tree.Conclusions:The influenza outbreak situation in schools was severe and has significant public health implications. Continuous surveillance is essential，and preventive strategies should be promptly adjusted based on the epidemiological and genetic characteristics of circulating strains.

Objective:To establish a novel rapid HIV-1 nucleic acid detection method based on reverse transcription-recombinase aided amplification（RT-RAA）and clustered regularly interspaced short palindromic repeats（CRISPR）technology.Methods:A total of 610 full-length HIV-1 genome sequences reported in China were analyzed，and primers targeting the relatively conserved region of the HIV-1 pol gene and three crRNAs were designed. The crRNAs were validated and screened，and the CRISPR detection system was optimized to establish a “one-pot” HIV-1 RT-RAA/CRISPR assay. Ten recombinant plasmids representing HIV-1 subtypes reported in China were constructed and serially diluted to evaluate the subtype coverage and sensitivity of the assay. The specificity of the assay was evaluated using plasma samples from hepatitis B virus（HBV），hepatitis C virus（HCV）and treponema pallidum（TP）-infected individuals. The clinical performance of the assay was preliminarily evaluated using 45 clinical samples（25 plasma samples from HIV-1 infected individuals and 20 plasma samples from healthy individuals）.Results:The crRNA combination demonstrated higher sequence coverage and higher terminal fluorescence compared to single crRNA. The HIV-1 RT-RAA/CRISPR assay established with the crRNA combination could complete the detection in 30 minutes. This method could detect all 10 reported HIV-1 subtypes in China，with a sensitivity as low as 1-10 copies/μl. No cross-reactivity was observed with HBV，HCV and TP. The results of clinical sample testing were 100% concordant with those of real time fluorescence quantitative RT-PCR assay.Conclusion:This study established a novel HIV-1 RT-RAA/CRISPR nucleic acid detection method with broad subtype coverage，simplicity，rapidity，high sensitivity，and strong specificity. The method shows potential for application in point-of-care testing of HIV-1.

Objective:To understand the characteristics of new infections in the newly reported HIV-1 infected population in Luzhou, to find out the characteristics of the high-risk population, which may provide a basis for developing precise prevention and control measures locally.Methods:HIV-1 LAg Avidity EIA test was applied for newly reported cases in Luzhou from 2018 to 2021. The chi-square test was used for univariate analysis, logistic regression model for multivariate analysis, and spatial autocorrelation and hotspot analysis were applied to explore the spatial distribution characteristics of new infections in Luzhou city.Results:A total of 4 494 cases reported in the odd-numbered months were selected for testing, with 673 newly infected cases and the proportion of newly infected cases was 14.98%. Newly infected cases were predominantly male (472/673, 70.13%), married (335/673, 49.78%), heterosexual transmission (621/673, 92.27%), age>50 years (520/673, 77.27%), and junior high school or lower education (599/673, 89.00%). The proportion of new infections in each year were 11.74% (129/1 099), 17.11% (247/1 444), 13.57% (154/1 134) and 17.50% (143/817), respectively, with a statistically significant difference ( χ2=20.024, P<0.001) and an upward trend ( χ2=5.997, P=0.014). There were statistically significant differences in different transmission routes, gender, education level, occupation, sample source and residence (all P<0.05). Logistic regression analysis showed that gender, marital status, transmission route, current address, and sample source were all influencing factors for new infections. There are spatial autocorrelation characteristics of new case incidence in 2018 and 2021, hotspot areas gradually shifted from dispersed to relatively concentrated, with the number fluctuating with reported year. Conclusions:The proportion of new HIV-1 infections in Luzhou is relatively low throughout the province, but it is on the rise. The proportion of new infections is higher among youth, students, homosexual transmission, and retired persons. Attention should be focused on hotspot areas and routine surveillance and testing of key populations in hotspot areas should be strengthened.

Objective:To understand the species of mosquitoes and the status of important mosquito-borne viruses in the Ningxia surveyed regions, to identify the dominant mosquito species and virus types, and to analyze their genetic characteristics, providing a scientific basis for predicting and controlling mosquito-borne infectious diseases.Methods:Mosquitoes were collected using light traps in Yinchuan and Wuzhong cities of the Ningxia Hui Autonomous Region, and the collected mosquitoes were classified and identified. Real-time polymerase chain reaction (PCR) was used to detect the Japanese encephalitis virus (JEV), West Nile virus (WNV), Chikungunya virus (CHIKV), Sindbis virus (SINV) carried by mosquitoes. The positive sample was subjected to sequencing the whole genome, and the phylogenetic tree of virus strains was constructed using bioinformatics methods.Results:From June to August 2023, a total of 8 561 mosquitoes of 3 genera and 6 species were collected in Yinchuan and Wuzhong cities, Ningxia, among which Culex pipiens pallens was the dominant species with 3 050 individuals, accounting for 35.63%; Anopheles sinensis with 2 379 individuals, accounting for 27.79%; Culex tritaeniorhynchus with 1 489 individuals, accounting for 17.39%; Caspian Aedes with 1 468 individuals, accounting for 27.79%; Aedes vexans with 152 individuals, accounting for 1.78%; and Culex modestus with 23 individuals, accounting for 0.27%. JEV GIb type was detected in the specimens of Culex tritaeniorhynchus collected in Qingtongxia city. Conclusions:The dominant mosquito species in the surveyed areas of Ningxia are primarily Culex pipiens pallens, and JEV GIb virus was detected in Culex tritaeniorhynchus in Qingtongxia city. This study provides basic data for understanding the current status of mosquitoes and mosquito-borne viruses in the Ningxia region and offers scientific guidance for further public health prevention and control measures.

Objective:To analyze the epidemiological and clinical characteristics of influenza A/B virus (IAV/IBV) infection in children aged 0-4 years in Jining city from 2022 to 2024.Methods:A retrospective analysis was conducted on the data of 3 106 influenza affected children who visited two monitoring outpost hospitals in Jining city from January 2022 to January 2024. They were separated into two groups based on the type of virus infection: IAV group (n=1 829) and IBV group (n=1 277). Two groups were compared for general information, epidemiological characteristics, and laboratory test indicators.Result:The majority of influenza patients were boys (59.01%) and 1-4 years old (63.01%), with peak body temperature mainly ranging from 37.8 to 38.9 ℃ (59.30%). Coughing (69.00%) and runny nose (66.03%) were the main manifestations. The onset season was concentrated in winter (42.43%) and spring (40.44%), and the exposure target were family members (51.90%), and the proportion of influenza vaccine injections (20.90%) was relatively low. The proportions of visit time≤3 d, peak body temperature≥39.0 ℃, myocardial damage, liver function damage, white blood cell count (WBC) of 4-10×10 9/L, and neutrophil percentage (N)>70% in the IAV group were higher than those in the IBV group ( P<0.05). The proportions of preschool children and WBC>10×10 9/L in the IBV group were higher than those in the IAV group ( P<0.05). Conclusions:Children aged 0-4 years who are infected with IAV in Jining City are more common in terms of high fever, early medical attention, impaired heart and liver function, normal WBC, and abnormal N elevation compared to those infected with IBV. However, children aged 0-4 who are infected with IBV have abnormally high WBC and are more common in daycare.

Objective:To establish a fluorescent quantitative RT-PCR assay based on N_sgRNA of SARS-CoV-2 and preliminarily apply it on real samples.Methods:Recombinant plasmid, specific primers and probes of N_sgRNA were designed and synthesized based on Wuhan-Hu-1/2019_MN908947 and synthesis mechanism of subgenomic RNA (sgRNA). Using recombinant plasmid as amplification templates, the optimal reaction conditions and reaction system were screened according to the Ct value, fluorescence intensity, and shape of amplification curve and was evaluated for sensitivity, reproducibility, and specificity. Meanwhile, the possibility of practical application of the method was explored by testing 172 clinical samples and 256 municipal wastewater samples. Results:A qRT-PCR assay for N_sgRNA in SARS-CoV-2 was initially established. The detection limit of the assay was 20 copies/mL, and the variation coefficients of in-batch (0.002%~0.767%) and batch to batch repetition (0.016%~0.752%) were less than 1%. Only N_sgRNA recombinant plasmid was detected in the specificity assay. So the method is more highly sensitive, specific and reproducible. The RatiosgRNA/ gRNA of clinical samples HK.3, EG.5.1, JN.1 and their sub-lineages and their corresponding urban sewage samples in epidemic period were significantly different ( P<0.05). There is a strong correlation between the median of RatiosgRNA/ gRNA in clinical samples and sewage samples in the same period (correlation coefficient r=1.000, P=0.010). Conclusions:In this study, a qRT-PCR method for detecting N_sgRNA of SARS-CoV-2 was established and the method has the characteristics of higher sensitivity, stronger specificity and better repeatability, and it can be used to detect SARS-CoV-2 infectivity.

Objective:To investigate the dynamic changes of cellular miRNA expression profiles in EBV latently infected Raji cells upon reactivation with Phorbol ester (TPA).Methods:Total RNA was extracted using TRIzol reagent from Raji cells treated with TPA at different time points (0 h, 24 h, 48 h). Small RNA libraries were constructed and sequenced on an Illumina SE50 platform. Differentially expressed miRNAs were identified, and their target genes were predicted and functionally annotated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were carried out through online tools. Additionally, miRanda and RNAhybrid software were used to predict cellular miRNAs targeting the EBV genome. Real-time RT-qPCR was employed to validate the expression levels of differentially expressed novel miRNAs.Results:High-throughput sequencing identified 1 301 celluar miRNAs, comprising 1 189 known and 112 novel miRNAs. A total of 264 known differentially expressed cellular miRNAs and 13 novel miRNAs were identified through high-throughput miRNA sequencing. Secondary structure prediction revealed that the novel miRNAs exhibited typical pre-miRNA hairpin structures. Stem-loop quantitative real-time PCR (RT-qPCR) validation of Novel_miR_183 and Novel_miR_242 did not exhibit a statistically significant difference ( F=1.407, P=0.370 7 for Novel_miR_183; F=1.277, P=0.397 0 for Novel_miR_242) between the TPA-stimulated and untreated groups. Target gene prediction analysis revealed that the differentially expressed cellular miRNAs were involved in various important biological processes and signaling pathways. Furthermore, 1 189 known cellular miRNAs and 108 novel miRNAs were predicted to target the EBV genome. Conclusions:Treatment of Raji cells with TPA stimulation successfully reactivated Raji cells and significantly altered their miRNA expression patterns. Differentially expressed miRNAs were identified, suggesting that these miRNAs probably play crucial roles in regulating EBV infection and replication by directly targeting the EBV genome.