Objective:To investigate the mosquito-borne viruses carried by mosquito specimens collected from Huachuan county and Huanan county in Heilongjiang province.Methods:Mosquito samples were collected locally in 2023 and processed in the laboratory. Homogenates of the mosquitoes were inoculated into cells for virus isolation, followed by molecular and bioinformatics analyses of the viral isolates.Results:In 2023, ten viral isolates were obtained from Anopheles sinensis specimens collected in Heilongjiang province, China. Among these isolates, one was identified as Culex flavivirus (CxFV), one as Menghai rhabdovirus (MRV), and eight as Nam Dinh virus (NDiV). The phylogenetic analysis showed that CxFV belongs to genotype I and is clustered with the strains isolated from Liaoning province in 2011 and Ningxia Hui autonomous Region in 2019 in the same evolutionary branch, with amino acid similarity ranging from 98.2% to 99.2% and nucleotide similarity ranging from 98.8% to 99.2%. The MRV strain belongs to the same evolutionary subclade as the strain detected in Guangdong, with both nucleotide and amino acid similarity of 98.0%. Eight NDiV isolates clustered with the South Korean isolates on the same evolutionary branch, forming an independent evolutionary sub-branch. The nucleotide similarity among these eight isolates ranged from 98.5% to 99.7%, while the amino acid similarity ranged from 98.1% to 99.7%. In comparison, when matched with other NDiV isolates from China, the nucleotide similarity of these eight isolates ranged from 94.1% to 97.8%, and the amino acid similarity ranged from 93.5% to 97.7%.Conclusions:This study represents the first isolation of CxFV, MRV, and NDiV in Heilongjiang province, China, and the findings provide fundamental data for the prevention and control of mosquito-borne viral diseases in this region.

Objective:To establish a method for the rapid detection of varicella-zoster virus (VZV) by recombinase-aid amplification (RAA) combined with Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system.Methods:Clinical samples of suspected herpes zoster in Shandong province and Shanghai from 2023 to 2024 were collected, nucleic acids of positive samples were extracted, RAA-specific primers and crRNA (CRISPR RNA, crRNA) were designed for the conserved region of VZV, and the fluorescence intensity generated by Cas12a non-specific cleavage of single-stranded fluorescent probes was used to screen highly sensitive crRNAs and optimize the concentrations of crRNA, Cas12a and ssDNA probes. The sensitivity and reproducibility of the RAA-CRISPR/Cas12a detection method were evaluated by using synthesized plasmids and clinical samples, and the specificity of the method was evaluated by using other viral nucleic acids. The method was used to detect clinical samples by using the method and quantitative real-time PCR (qPCR) method, and the detection rate and consistency of the two method were compared.Results:The highly sensitive crRNA-4 was screened from the four crRNAs designed, and a VZV detection method for RAA-CRISPR/CAS12a based on fluorescence intensity measurement was established, which could be detected at 37℃ in 45 min, and the sensitivity of the detection could reach 10 copies/μL, a minimum clinical sample with a Ct value of 38.980 can be detected. It has high specificity and no cross-reactivity with Adenovirus 7, Herpes simplex virus type I, Herpes simplex virus type II, Coxsackieviruses A16, Cytomegalovirus, Epstein-Barr virus, Measles virus, Mumps virus, Enterovirus 71, Japanese encephalitis virus genotype 5. It has good stability, and can be successfully detected in low, medium and high concentrations of viral positive plasmids with good consistency. The detection rate of the clinically positive samples was 100%, which was completely consistent with the qPCR test result.Conclusions:RAA isothermal amplification technology combined with CRISPR-CAS12a technology was used to establish an accurate method for the detection of VZV virus, which was highly sensitive, specific, and had low requirements for experimental conditions, and could be completed within 45 min, which could provide strong technical support for the early detection of VZV.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

Postoperative infection of internal fixation of closed fractures the lower limbs in adults represents a devastating complication, characterized by diagnostic challenges, prolonged treatment duration and high disability rates. Current management of these infections faces multiple challenges, such as difficulties in early accurate diagnosis, and various controversies about the treatment plan, leading to poor overall diagnosis and treatment results. To address these issues, based on evidence-based medicine and principles with emphasis on scientific rigor, clinical applicability and innovation, the Trauma Branch of the Chinese Medical Association, Orthopedic Branch of the Chinese Medical Doctor Association, Orthopedics Branch of the Chinese Medical Association, and Trauma Orthopedics and Polytrauma Group of the Resuscitation and Emergency Committee of the Chinese Medical Doctor Association have collaboratively organized a panel of relevant experts to develop the Guideline for diagnosis and treatment of infection after internal fixation of closed lower limb fractures in adults ( version 2025). The guideline proposed 10 recommendations, aiming to provide a foundation for standardized diagnosis and treatment of postoperative infection in adults with closed lower limb fractures.

Objective:To investigate the mosquito-borne viruses carried by mosquito specimens collected from Huachuan county and Huanan county in Heilongjiang province.Methods:Mosquito samples were collected locally in 2023 and processed in the laboratory. Homogenates of the mosquitoes were inoculated into cells for virus isolation, followed by molecular and bioinformatics analyses of the viral isolates.Results:In 2023, ten viral isolates were obtained from Anopheles sinensis specimens collected in Heilongjiang province, China. Among these isolates, one was identified as Culex flavivirus (CxFV), one as Menghai rhabdovirus (MRV), and eight as Nam Dinh virus (NDiV). The phylogenetic analysis showed that CxFV belongs to genotype I and is clustered with the strains isolated from Liaoning province in 2011 and Ningxia Hui autonomous Region in 2019 in the same evolutionary branch, with amino acid similarity ranging from 98.2% to 99.2% and nucleotide similarity ranging from 98.8% to 99.2%. The MRV strain belongs to the same evolutionary subclade as the strain detected in Guangdong, with both nucleotide and amino acid similarity of 98.0%. Eight NDiV isolates clustered with the South Korean isolates on the same evolutionary branch, forming an independent evolutionary sub-branch. The nucleotide similarity among these eight isolates ranged from 98.5% to 99.7%, while the amino acid similarity ranged from 98.1% to 99.7%. In comparison, when matched with other NDiV isolates from China, the nucleotide similarity of these eight isolates ranged from 94.1% to 97.8%, and the amino acid similarity ranged from 93.5% to 97.7%.Conclusions:This study represents the first isolation of CxFV, MRV, and NDiV in Heilongjiang province, China, and the findings provide fundamental data for the prevention and control of mosquito-borne viral diseases in this region.

Objective:To establish a method for the rapid detection of varicella-zoster virus (VZV) by recombinase-aid amplification (RAA) combined with Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system.Methods:Clinical samples of suspected herpes zoster in Shandong province and Shanghai from 2023 to 2024 were collected, nucleic acids of positive samples were extracted, RAA-specific primers and crRNA (CRISPR RNA, crRNA) were designed for the conserved region of VZV, and the fluorescence intensity generated by Cas12a non-specific cleavage of single-stranded fluorescent probes was used to screen highly sensitive crRNAs and optimize the concentrations of crRNA, Cas12a and ssDNA probes. The sensitivity and reproducibility of the RAA-CRISPR/Cas12a detection method were evaluated by using synthesized plasmids and clinical samples, and the specificity of the method was evaluated by using other viral nucleic acids. The method was used to detect clinical samples by using the method and quantitative real-time PCR (qPCR) method, and the detection rate and consistency of the two method were compared.Results:The highly sensitive crRNA-4 was screened from the four crRNAs designed, and a VZV detection method for RAA-CRISPR/CAS12a based on fluorescence intensity measurement was established, which could be detected at 37℃ in 45 min, and the sensitivity of the detection could reach 10 copies/μL, a minimum clinical sample with a Ct value of 38.980 can be detected. It has high specificity and no cross-reactivity with Adenovirus 7, Herpes simplex virus type I, Herpes simplex virus type II, Coxsackieviruses A16, Cytomegalovirus, Epstein-Barr virus, Measles virus, Mumps virus, Enterovirus 71, Japanese encephalitis virus genotype 5. It has good stability, and can be successfully detected in low, medium and high concentrations of viral positive plasmids with good consistency. The detection rate of the clinically positive samples was 100%, which was completely consistent with the qPCR test result.Conclusions:RAA isothermal amplification technology combined with CRISPR-CAS12a technology was used to establish an accurate method for the detection of VZV virus, which was highly sensitive, specific, and had low requirements for experimental conditions, and could be completed within 45 min, which could provide strong technical support for the early detection of VZV.

Objective:To analyze the growth characteristics of different genotypes of Japanese encephalitis virus (JEV) in different cell lines, and to provide scientific basis for the selection of cell lines in the study of JEV.Methods:BHK-21, Vero, C6/36, PK-15, DF-1, N2a, SH-sy5y and MDCK cell lines were selected. The proliferation ability of genotype 1 (NX1889 strain), genotype 3 (P3 strain) and genotype 5 (XZ0934 strain) JEV in these cell lines was evaluated by plaque assay and RT-qPCR.Results:Significant cytopathogenic effects (CPE) were observed in BHK-21, Vero, C6/36, DF-1, N2a and PK-15 cell lines across all three JEV genotypes. However, no significant differences in CPE characteristics were observed within the same cell line. SH-sy5y and MDCK cell lines did not show significant CPE, but virus proliferation was detected in SH-sy5y cell line, while MDCK cell line were found to be insensitive to JEV. No significant difference was observed in the proliferation curves of G1, G3 and G5 JEV in BHK-21, Vero and SH-sy5y cell lines. In C6/36 and PK-15 cell lines, the titer of G1 JEV was higher than that of G3 and G5. In DF-1 cell line, G5 demonstrated a higher titer than the other two genotypes, whereas in N2a cell line, G5 showed a lower titer than the other two.Conclusions:There are differences in the proliferation of three different genotypes of JEV in different cell lines, which can provide reference for the study of JEV in different directions.

Objective Genotypes(G)1,3,and 5 of the Japanese encephalitis virus(JEV)have been isolated in China,but the dominant genotype circulating in Chinese coastal areas remains unknown.We searched for G5 JEV-infected cases and attempted to elucidate which JEV genotype was most closely related to human Japanese encephalitis(JE)in the coastal provinces of China. Methods In this study,we collected serum specimens from patients with JE in three coastal provinces of China(Guangdong,Zhejiang,and Shandong)from 2018 to 2020 and conducted JEV cross-neutralization tests against G1,G3,and G5. Results Acute serum specimens from clinically reported JE cases were obtained for laboratory confirmation from hospitals in Shandong(92 patients),Zhejiang(192 patients),and Guangdong(77 patients),China,from 2018 to 2020.Seventy of the 361 serum specimens were laboratory-confirmed to be infected with JEV.Two cases were confirmed to be infected with G1 JEV,32 with G3 JEV,and two with G5 JEV. Conclusion G3 was the primary infection genotype among JE cases with a definite infection genotype,and the infection caused by G5 JEV was confirmed serologically in China.

Objective:To investigate the species and distribution of mosquito-borne arboviruses in the southeastern part of Gansu province.Methods:In 2023, mosquitoes were collected using ultraviolet lights in Longnan and Tianshui regions of Gansu province. After classification by morphology, about 50 are only 1 batch. RT-qPCR was used to detect the RNA of Japanese encephalitis virus (JEV), Banna virus (BAV), Getah virus (GETV), Culex flavivirus (CxFV) and Tahyna virus (TAHV). The genomes of the positive samples were sequenced and the genetic evolution of the virus genomes were analyzed by bioinformatics software.Results:In total, there were 8 176 mosquitoes from 4 genera and 9 species collected from Longnan and Tianshui from June to August 2023. Culex tritaeniorhynchus was the most common species with 55.80% (4 562/8 176) of the total mosquitoes collected, followed by 16.43% (1 343/8 176) of Culex pipiens pallens. A total of 263 batches of samples were obtained, and the nucleic acid test showed that 1 batch was positive for JEV, 2 batches were positive for BAV, 3 batches were positive for GETV and 25 batches were positive for CxFV. Conclusions:Culex tritaeniorhynchus was the dominant mosquito species in the southeastern part of Gansu province, and local mosquitoes carried a variety of arboviruses.

Objective:To understand the situation of arboviruses carried by mosquito specimens in Daozhen county, Guizhou province.Methods:In July 2023, mosquito specimens were collected in Daozhen county, Guizhou province, using photocatalytic mosquito trap method. Reverse transcription polymerase chain reaction (RT-PCR) technology was used to detect the types of viruses carried by mosquitoes, and phylogenetic trees were constructed using the neighbor-joining method to analyze the phylogenetic position of the detected viruses.Results:A total of 5 313 mosquito specimens belonging to 2 genera and 2 species were collected in Daozhen county, Guizhou province, including 3 953 Culex tritaeniorhynchus, 1 355 Armigeres subalbatus, and 5 other mosquito species. The specimens were divided into 54 batches according to their species for grinding, nucleic acid extraction, and testing. Among them, 6 batches of Cx. tritaeniorhynchus specimens tested positive for flavivirus genus using universal primers, and further identification revealed that 5 batches were positive for Japanese encephalitis virus (JEV) nucleic acid, and 1 batch was positive for Tembusu virus (TMUV) nucleic acid. Phylogenetic analysis showed that the detected JEV strains were all genotype I and fell within the same evolutionary branch; the detected TMUV was located on the third branch of the evolutionary tree, with the main host source of the strains on this branch being mosquitoes. Conclusions:In the mosquito specimens collected in Daozhen county, Guizhou province in 2023, genotype I JEV and TMUV were detected, with TMUV being detected for the first time in mosquitoes in Guizhou province. It is essential to enhance the surveillance of JEV and TMUV to mitigate the potential public health risks they pose.