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:This study aimed to analyze the genetic variation of the human papillomavirus (HPV) type 39 genomes and to predict and screen the dominant T-cell and B-cell epitopes of the viral early proteins (E1, E2, E6, E7) and late proteins (L1, L2).Methods:A total of 70 full-length sequences of HPV39 variants were retrieved from the clinical samples and the National Center for Biotechnology Information (NCBI) to construct a phylogenetic tree, analyze genetic polymorphisms, and predict the physicochemical properties of the viral proteins. Next, T-cell and B-cell epitopes were predicted using IEDB and ABCpred, and potential dominant epitopes were further selected based on parameters such as the secondary structure of the epitope region, peptide flexibility, hydrophilicity, surface accessibility and antigenicity. Finally, a homology analysis of the potential dominant epitopes was performed with 12 high-risk HPV types.Results:HPV39 variants from different sources can be clustered into two lineages (A and B), each exhibiting distinct mutation patterns. The mutation rate was the highest in E7 and the lowest in E1 among the different viral genes. However, these nucleotide/amino acid mutations did not significantly impact the physicochemical properties of the viral proteins. After prediction and screening, 5 and 6 potential dominant B-cell epitopes were identified in both L1 and L2, respectively. E1, E2, E6, and E7 yielded 18, 10, 4, and 1 potential dominant HLA-I restricted T-cell epitopes, respectively. Additionally, E1, E2, and E6 yielded 7, 3, and 2 potential dominant HLA-II restricted T-cell epitopes, respectively. Homology analysis indicated that T-cell dominant epitopes in E1, E2, and E6, as well as B-cell epitopes in L2, showed high homology (93%-100%) with HPV68, HPV33, HPV45, and HPV59.Conclusions:Bioinformatics analysis and prediction revealed that HPV39 variants can be clustered into two main evolutionary branches, A and B, each exhibiting a specific mutation pattern. The viral proteins contain potential dominant T-cell and B-cell epitopes that can be further investigated, providing valuable theoretical support for the development of HPV39-related peptide-based vaccines and therapeutics.

Objective:To investigate the role of ubiquitin-specific protease 21 (USP21) in enterovirus group A type 71 (EV-A71) infection.Methods:Peripheral blood mononuclear cells (PBMC) were obtained from a cohort of 24 children infected with EV-A71 and 24 healthy children. Expression of USP21 was determined by real-time fluorescence quantitative PCR (qPCR). Additionally, the impact of USP21 overexpression or knockout on EV-A71 replication was evaluated using a combination of qPCR and western blot (WB) analysis. Furthermore, WB was employed to measure the levels of EV-A71 structural protein VP1, phosphorylated interferon regulatory factor 3 (IRF3) and other key molecules in the RIG-I-like receptor (RLR) signaling pathway. Co-immunoprecipitation (Co-IP) was utilized to investigate the effects of USP21 on the ubiquitin levels of EV-A71 nonstructural protein 2A protease (2A pro). Results:In comparison to healthy children, the expression of USP21 mRNA in PBMC of children infected with EV-A71 was notably elevated. The overexpression of USP21 significantly enhanced the cytopathic effects induced by EV-A71, upregulated levels of VP1 mRNA and protein, and facilitated EV-A71 replication, leading to a decrease in cell activity with increasing levels of USP21 transfection. Following the knockout of the USP21 gene, the VP1 mRNA levels were significantly declined in comparison to the control group. Furthermore, the overexpression of USP21 was found to have no impact on the transcriptional activity of EV-A71 2A pro. However, it was observed to enhance the expression of 2A pro protein, reduce the ubiquitination of 2A pro, suppress the protein levels of mitochondrial antiviral signaling protein (MAVS) and melanoma differentiation-associated gene 5 (MDA5), as well as decrease the phosphorylation of IRF3. Additionally, the induction of IFN-β mRNA by EV-A71 infection was downregulated. Conclusions:USP21 has been shown to enhance the replication of EV-A71 through the downregulation of 2A pro ubiquitination, suppression of MAVS and MDA5 protein expression, and inhibition of the interferon signaling pathway.

Objective:To understand the molecular evolutionary characteristics of the recombinant strain GII.3[P12] of norovirus acute gastroenteritis outbreaks and aggregated outbreaks in China from 2022 to 2023.Methods:Epidemiological information, case information, clinical samples, as well as detection and genotyping information of norovirus outbreaks and aggregated outbreaks from 2022 to 2023 were collected; positive samples of the GII.3[P12] recombinant strain were subjected to nucleic acid extraction, whole-genome amplification, and sequence analysis; and homology simulation method were used to construct a three-dimensional structure and predict antigenic epitopes.Results:From January 2022 to December 2023, a total of 1 136 norovirus outbreaks and aggregated outbreaks were reported in China′s norovirus outbreak surveillance network, and genotyping result were successfully obtained for 942 outbreaks, with GII dominating, accounting for 76.0% (716/942), and the proportion of GI and mixed genotypes being 15.8% (149/942) and 8.2% (77/942). Norovirus outbreaks caused by GII were dominated by GII.3[P12] (22.5%, 161/716), while other major genotypes included GII.17[P17] (18.7%, 134/716), GII.4_Sydney 2012[P16] (11.6%, 83/716) and GII.6[P7] ( 11.3%, 81/716). 2022-2023 Outbreaks caused by GII.3[P12] were concentrated in February-March (54.0%, 87/161), with the main outbreaks occurring in nursery and primary schools (87.5%), the mode of transmission was mainly human-to-human (68.9%), and the main susceptible population was children aged 3-7 years (93.3%). In this study, the genome sequences of 25 GII.3[P12] recombinant strains were obtained, and according to the phylogenetic analysis, it was shown that the GII.3[P12] recombinant strains in China in 2022-2023 belonged to the Cluster IV cluster of sublineage b (7 strains) and sublineage c (18 strains). A total of 11 linear and 8 conformational epitopes were predicted by epitope prediction analysis, and the predicted linear and conformational epitopes had overlapping positions, and each conformational epitope was part of the predicted linear epitope with conserved potential antigen-binding and receptor-binding sites.Conclusions:The recombinant strain GII.3[P12] is one of the epidemic strains that will cause outbreaks and clusters of norovirus in China in 2022-2023, and its genome did not undergo significant mutation.

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.

Objective:To compare the enrichment effects of ultrafiltration, polyethylene glycol (PEG) precipitation, aluminum salt precipitation, and anionic membrane adsorption-elution on viruses in drinking water.Methods:Using phage MS2 as the target virus, three different concentrations of drinking water samples were prepared, and the samples were enriched by ultrafiltration 1, ultrafiltration 2, PEG precipitation, aluminum salt precipitation, and anionic membrane adsorption-elution method, respectively. Real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-qPCR) was used to quantify MS2 nucleic acid in pre and post concentrated samples and the recovery rates of MS2 in samples with high, medium and low concentrations were compared among the five methods.Results:Comparing the MS2 enrichment recovery rates of individual enrichment method in water samples of different concentrations, ultrafiltration method 1, PEG precipitation method, aluminum salt precipitation method, and membrane adsorption-elution method were not affected by the sample concentration, and the differences of the recovery rates for the three concentration water samples among the four methods were not statistically significant ( P>0.05). The MS2 enrichment recovery rates of the five enrichment methods were significantly different in all concentration samples ( P<0.05). The recovery rates of ultrafiltration method 1 were higher in all three concentration samples, followed by aluminum salt precipitation and anionic membrane adsorption-elution, PEG precipitation were higher in high concentration samples, but lower in low and medium concentration samples, and the recovery rates of ultrafiltration method 2 were the lowest in all three concentration samples. Comparing the Ct values of MS2 in the enriched samples by five methods, the Ct values of ultrafiltration method 1 were the smallest in the three concentration water samples. There was no statistically significant difference in MS2 Ct values among the five enrichment methods in the medium and high concentration water samples ( P>0.05). In low concentration simulated water samples, only the difference of MS2 Ct value between ultrafiltration method 1 and ultrafiltration method 2 was statistically significant ( Z=16.000, P=0.016). Conclusions:Considering the operation simplicity, operation time and virus recovery rate after enrichment, ultrafiltration was the most effective method for virus enrichment in drinking water.

Objective:The SARS-CoV-2 has a high natural mutation rate, and dynamic monitoring of virus variants remains a key focus in current COVID-19 prevention and control efforts.Methods:In this study, a sensitive and rapid method for detecting SARS-CoV-2 omicron variant nucleic acid was established based on the BMD-PCR technology.Results:This method showed good specificity, and had no cross-reactivity with 11 common viruses transmitted via the respiratory and gastrointestinal tracts, and the limit of detection is 555 copies/ml. Compared with SARS-CoV-2 whole-genome sequencing result, among 50 samples with original Ct values ≤32 tested for the Omicron variant, 49 samples tested positive for the N679K mutation site using BMD-PCR Omicron variant detection, achieving a concordance rate of 98.00%. For 30 samples JN.1 lineage, 29 samples tested positive for the K356T mutation site using BMD-PCR JN.1 lineage detection, with a concordance rate of 96.67%. For 10 samples with original SARS-CoV-2 detection Ct values between 35 and 32, 7 samples tested positive for the N679K mutation site using BMD-PCR Omicron variant detection, Resultsing in a detection rate of 70.00%. For samples with SARS-CoV-2 nucleic acid detection Ct values>35, the detection rate for the N679K mutation site in the BMD-PCR Omicron variant was 20.00%.Conclusions:This method can serve as a high-throughput supplementary approach for the preliminary identification of SARS-CoV-2 variant genotypes.