Abstract Background Hand, foot, and mouth disease (HFMD) is a common enteric infectious disease that poses a threat to children’s health. The disease exhibits high epidemic intensity and frequent outbreak clusters in Beijing, the capital of China. However, the spatiotemporal characteristics of these outbreak clusters and their future epidemic trends remain poorly understood. This study aims to fill this gap by analyzing the spatiotemporal epidemiology of HFMD outbreak clusters and developing a forecasting model to inform targeted prevention strategies. Methods The present study analyzed data on HFMD outbreak clusters in Beijing from 2019 to 2024. Epidemiological characteristics were described, including demographic features, clinical manifestations, transmission settings, and spatial distribution. Group comparisons were performed using Kruskal-Wallis and chi-squared tests. The spatial distribution of outbreak clusters was visualized and analyzed by geographic region. A Seasonal Autoregressive Integrated Moving Average (SARIMA) model was developed to forecast incidence trends. Results Beijing reported 4,265 HFMD outbreak clusters (12,396 cases) during 2019–2024, exhibiting a biennial high-incidence pattern. Compared to 2019 (1,206 clusters), the mean annual clusters during 2020–2022 decreased by 74.4% (305/year), rebounding to 1,719 clusters in 2023—42.5% higher than 2019. Most clusters (77.2%) involved < 5 cases. Median age was 5 years (IQR: 4–7), increasing to 6 years in 2023. Males predominated (p < 0.001). School-aged cases rose to 54.4% in 2023, while kindergarten cases declined. Kindergartens predominated overall (52.7%), but schools became the main setting in 2023 (44.9%), 4.2 times the pandemic average (10.6%). Clusters concentrated in near-suburban areas (> 50% in multiple years). CV-A6 was dominant (60.2%), peaking at 90.7% in 2023; EV-A71 was rare (0.12%). Cluster size varied by pathogen (p < 0.001). The SARIMA model forecast a bimodal pattern for 2025, with primary autumn peak (299 clusters) and secondary summer peak (165 clusters). Conclusion HFMD outbreak clusters in Beijing exhibited a biennial pattern, with suppression during 2020–2022 due to COVID-19 NPIs followed by a rebound in 2023 exceeding pre-pandemic levels. Clusters concentrated in near-suburban areas with consistent bimodal seasonality, and the SARIMA model projects a similar pattern for 2025. These findings underscore the need for setting-specific strategies prioritizing schools alongside kindergartens, targeted interventions in high-risk suburbs, and continued pathogen monitoring.

BACKGROUND:Hand, foot, and mouth disease (HFMD), particularly EV-A71, has caused large-scale epidemics in the Asia-Pacific region, with China alone reporting over 2 million annual cases and causing a substantial morbidity and mortality. While EV-A71 vaccination was introduced in 2016 and COVID-19 non-pharmaceutical interventions (NPIs) were implemented from 2020-2022, comprehensive evidence on their independent and combined effects on HFMD epidemiology remains scarce. We aimed to quantify the impact of vaccination, NPIs, and post-pandemic policy relaxation on HFMD incidence and pathogen distribution. METHODS:We conducted an interrupted time series segmented regression analysis using a 14-year surveillance dataset (January 2011-December 2024) from Beijing's National Notifiable Disease Reporting System and citywide pathogen surveillance network. The study population included all HFMD cases reported in Beijing. We defined four intervention periods: baseline (pre-vaccination), vaccination introduction (August 2016), stringent NPIs (January 2020), and reopening (January 2023). Primary outcomes were HFMD incidence rates and incidence rate ratios (IRRs). We estimated prevented cases under counterfactual scenarios. RESULTS:Among 324,623 reported HFMD cases across the 14-year study period, interrupted time series regression demonstrated that vaccination was associated with a 33% reduction in incidence (IRR 0.67, 95% CI: 0.49-0.91); cumulatively over 8 years (2016-2024), this was estimated to have prevented 23.8% of cases that would have occurred without vaccination. Stringent NPIs were associated with an 84% reduction (IRR = 0.16, 95% CI: 0.06-0.41); cumulatively, during the intervention period (2020-2022), NPIs were estimated to have prevented 82.6% of cases. Following policy relaxation, incidence rebounded 2.53-fold (95% CI: 0.64-9.92), although this increase did not reach statistical significance. In absolute terms, monthly mean case counts declined from 3001 (baseline) to 1886 following vaccination introduction (37.2% decrease), and further to 299 during stringent NPIs (90.0% decrease from baseline), before surging to 1503 post-reopening, a fivefold increase from the NPI period. Pathogen surveillance revealed EV-A71 prevalence declined from 30.5% (baseline) to 4.5% (vaccination period), while coxsackievirus A6 emerged as the dominant serotype, from 9.5% (baseline period) to 56.2% (vaccination period). CONCLUSIONS:EV-A71 vaccination and NPIs were each associated with reduced HFMD transmission, but policy relaxation was followed by a substantial resurgence. The observed serotype replacement with non-vaccine-type enteroviruses highlight critical gaps in current prevention strategies. Sustaining HFMD control requires optimizing vaccine design, developing multivalent vaccines, maintaining high coverage, and integrating targeted NPIs during high-transmission seasons.

BACKGROUND:Hand, foot, and mouth disease (HFMD) remains a major public-health concern in China. While the monovalent EV-A71 vaccine has effectively reduced EV-A71-associated cases, it offers no protection against CV-A16. The introduction of a bivalent EV-A71/CV-A16 vaccine may offer broader protection, but its economic viability under different immunization strategies remains uncertain. METHODS:We developed a dynamic transmission model integrated with cost-effectiveness analysis to assess the epidemiological and economic impact of a hypothetical bivalent EV-A71/CV-A16 vaccine in China. Based on the immunization program policy, seven vaccination strategies, vaccine effectiveness (VE) levels ranging from 50-95% against EV-A71/CV-A16, and coverage levels from 0-95% were evaluated. The threshold vaccine price (TVP) was derived based on incremental cost-effectiveness ratio (ICER) calculations. Cost-effectiveness was assessed using willingness-to-pay (WTP) thresholds defined as 1-3 times the gross domestic product (GDP) per capita. RESULTS:The mean cost of two doses of the monovalent EV-A71 vaccine was USD133.0 (95% CI: 126.9-139.1). Strategy 2, which targeted individuals unvaccinated with the monovalent EV-A71 vaccine, demonstrated the most favorable cost-effectiveness. At 45% coverage and 85% vaccine effectiveness, the estimated threshold price per dose was USD 107.7 (95% CI: 103.4-112.0), with threshold vaccine prices increasing as coverage declined. When vaccination coverage exceeded 80%, the threshold vaccine price decreased substantially, falling below USD 45.9 (95% CI: 43.5-48.3) per dose. CONCLUSIONS:Large-scale inclusion in the national immunization program may not be economically justified at current cost levels. Targeted voluntary vaccination of unvaccinated, susceptible populations represents a more cost-effective and practical strategy during the early stage of vaccine introduction.

Coxsackievirus A6 (CVA6) is a major pathogen responsible for numerous outbreaks of hand, foot, and mouth disease (HFMD) worldwide. This study investigates the molecular evolution and recombination of CVA6 in Beijing, China. Full-length sequences of 54 CVA6 from Beijing (2019-2023) were obtained through metagenomic next-generation sequencing and Sanger sequencing. These sequences were compared with representative sequences from GenBank to analyse their phylogenetic characteristics, recombination diversity, and evolutionary dynamics. The 54 CVA6 strains co-circulated with those from multiple provinces in China, as well as from South Korea and Japan. Phylogenetic analysis revealed a novel D3c branch, with the VP1 T283A amino acid mutation identified as a key change in its formation. One sequence belonged to the D3a branch, while 53 sequences belonged to the D3c branch. Recombination analysis identified RF-A (46, 85.1%) and three novel recombinant forms (RFs): RF-Z (1, 1.9%), RF-AA (1, 1.9%), and RF-AB (6, 11.1%). Bayesian phylogenetic analysis estimated that the most recent common ancestor of D3c emerged in August 2013 (95% highest probability density (HPD): May 2012 to September 2014), with recombination events occurring in RF-Z (2017-2019), RF-AA (2019-2023), and RF-AB (2021-2023). In conclusion, we revealed a globally circulating CVA6 D3c branch and identified three novel RFs, providing valuable insights for the intervention and control of HFMD.

Coxsackievirus A16 (CV-A16) is a significant etiologic agent of hand, foot, and mouth disease (HFMD) and herpangina (HA), with the capacity to progress to severe complications, including encephalitis, aseptic meningitis, acute flaccid paralysis, myocarditis, and other critical conditions. Beijing's epidemiological surveillance system, established in 2008, encompasses 29 hospitals and 16 district disease control centers. From 2019 to 2021, the circulation of CV-A16 was characterized by the co-circulation of B1a and B1b clades. Multiple cases of HFMD linked to clade B1c has not been reported in Beijing until 2022. This study enrolled 400 HFMD and 493 HA cases. Employing real-time RT-PCR, 368 enterovirus-positive cases were identified, with 180 selected for sequencing. CV-A16 was detected in 18.89% (34/180) of the cases, second only to CV-A6, identified in 63.33% (114/180). Full-length VP1 gene sequences were successfully amplified and sequenced in 22 cases, revealing the presence of clades B1a, B1b, and B1c in 14, 3, and 5 cases, respectively. A cluster of five B1c clade cases occurred between June 29 and July 17, 2022, within a 7-km diameter region in Shunyi District. Phylogenetic analysis of five complete VP1 gene sequences and two full-genome sequences revealed close clustering with the 2018 Indian strain (GenBank accession: MH780757.1) within the B1c India branch, with NCBI BLAST results showing over 98% similarity. Comparative sequence analysis identified three unique amino acid variations (P3S, V25A, and I235V). The 2022 Shunyi District HFMD cases represent the first instances of spatiotemporally correlated CV-A16 B1c clade infections in Beijing, underscoring the necessity for heightened surveillance of B1c clade CV-A16 in HFMD and HA in this region.

Abstract Background Enterovirus 71(EV71)-associated hand, foot and mouth disease (HFMD) decreased dramatically in Beijing from 2009 to 2019. This study was to investigate the epidemiological characteristics, evolutionary dynamics, geographic diffusion pathway, and other features of EV71 in Beijing, China. Methods We conducted a retrospective study of EV71-associated HFMD and its causative agent in Beijing, China, from 2009 to 2019. Phylogenetic and phylogeographic methods based on the EV71 genome were used to determine the evolution features, origin, and spatiotemporal dynamics. Positive selection sites in the VP1 gene were identified and exhibited in the tertiary structure. Bayesian birth-death skyline model was used to estimate the effective reproductive number (Re). Results EV71-associated HFMD decreased greatly in Beijing. From 2009 to 2019, EV71 strains prevalent in Beijing shared high homology in each gene segment and evolved with a rate of 4.99*10− 3 substitutions per site per year. The genetic diversity of EV71 first increased and peaked in 2012 and then decreased with fluctuations. The time to the most recent common ancestor (TMRCA) of EV71 in Beijing was estimated around 2003 when the EV71 strains were transmitted to Beijing from east China. Beijing played a crucial role in seeding EV71 to central China as well. Two residues (E145Q/G, A293S) under positive selection were detected from both the VP1 dataset and the P1 dataset. They were embedded within the loop of the VP1 capsid and were exposed externally. Mean Re estimate of EV71 in Beijing was about 1.007. Conclusion In recent years, EV71 was not the primary causative agent of HFMD in Beijing. The low Re estimate of EV71 in Beijing implied that strategies for preventing and controlling HFMD were performed effectively. Beijing and east China played a crucial role in disseminating EV71 to other regions in China.

Monkeypox (mpox) is a zoonotic disease caused by the mpox virus (MPXV) that has been primarily limited to Central and West African nations since its discovery. The recent spread of the West African lineage of MPXV in historically unaffected countries has raised concerns for global public health. Despite a significant decrease in global mpox cases, there is still a risk of a global resurgence. This study reports the first local case of mpox caused by an imported case in the Chinese mainland. Polymerase chain reaction (PCR) diagnosed the two cases, and the viral genomes were obtained by next-generation sequencing. Genomic analysis revealed that the two strains shared an identical genome sequence and belonged to the B.1.3 branch of the West African lineage, which is the first local case of mpox caused by an imported case in the Chinese mainland, highlighting the potential threat of mpox in China and the immediate need for adequate surveillance measures.

Hand,foot,and mouth disease （HFMD） is an acute infection caused by enteroviruses that is commonly seen in children [1] .High infectivity,large number of asymptomatic infections,complex transmission routes,and rapid spread make it difficult to control HFMD.Since 2008,China has reported＞ 23 million HFMD cases,including＞0.15million severe cases [2] .HFMD tops the list of notifiable infectious diseases in terms of case number and incidence rate,leading to a huge disease burden [3] .Timely and accurate assessment of HFMD epidemics is essential for a holistic understanding of the outbreaks and for effective prevention and control strategies.Currently,there are no quantitative indicators to determine the duration and intensity of HFMD epidemics in Beijing.

Coxsackievirus A16 (CV‐A16) is a significant pathogen responsible for causing hand foot and mouth disease (HFMD) and herpangina (HA). This study aimed to investigate the recent evolution and spread of CV‐A16 by monitoring HFMD and HA cases in 29 hospitals across 16 districts in Beijing from 2019 to 2021. The first five cases of HFMD and the first five cases of HA each month in each hospital were included in the study. Real‐time reverse transcription polymerase chain reaction was used to identify CV‐A16, CV‐A6, and EV‐A71. From each district, two to four CV‐A16 positive samples with a relatively long sampling time interval every month were selected for sequencing. A total of 3344 HFMD cases and 2704 HA cases were enrolled in this study, with 76.0% (2541/3344) of HFMD and 45.4% (1227/2704) of HA cases confirmed to be infected by enterovirus. Among the EV‐positive samples, CV‐A16 virus was detected in 33.61% (854/2541) of HFMD cases and 13.4% (165/1227) of HA cases, with the predominant cluster being B1a. Both B1a and B1b had a co‐circulation of local and imported strains, with different origin time (1993 vs. 1995), different global distribution (14 countries vs. 10 countries), and different transmission centers but mainly distributed in the southern and eastern regions of Beijing. Strengthening surveillance of HFMD in southern and eastern regions will improve the prevention and control efficiency of enterovirus infections.

The first indigenous incidence of Mpox (previously known as monkeypox) within Chinese mainland was documented in May 2023, with subsequent local and imported cases identified. A comprehensive understanding of the Mpox virus's (MPXV) characteristics within Beijing remains incomplete. In this study, 84 MPXV genomes from 82 local incidents and two imported instances, detected between May and July 2023, were analyzed. All MPXV strains fell within lineage C.1 of the West African clade, displaying limited genetic heterogeneity, encompassing 76-87 nucleotide substitutions and holding nucleotide identities between 99.996% and 100%. Phylogenetic exploration indicated that all genomes exhibited high homology to those presently prevalent in neighboring East Asian and Southeast Asian regions. Forty-six distinct haplotypes were identified among the strains, with 36.90% of genomes corresponding to four common haplotypes, suggesting repeated cross-regional introductions and restrained distribution via recurrent local transmission. These findings elucidate the genetic diversity and phylogenesis of MPXVs during their nascent transmission within Beijing and provide vital information to enhance future Mpox containment strategies.

Objective:To explore the the detection patterns of mpox virus in different types of clinical specimen, so as to provide evidence for the diagnosis of mpox cases and the formulation of public health policies.Methods:The throat swabs, skin lesion swabs, blood and anal swabs from the cases were collected. Real-time quantitative PCR method was used to detect monkeypox virus DNA in the samples. The differences in the positive detection rate of different sample types were analyzed the Prism software was used to analyze the differences in the viral loads (Ct values) in different types of samples and in different sampling time of the same sample type.Results:The positive detection rates of throat swabs, skin lesion swabs, blood, and anal swabs in the 210 confirmed cases were 70.95%, 98.97%, 75.26% and 88.89%, respectively. The median Ct values for the throat swab group, skin lesion swab group, blood group, and anal swab group were 31, 17, 34, and 26, respectively. The difference in viral loads (Ct values) among patient groups with different sampling intervals for skin lesion swab group and anal swab group were statistically significant.Conclusions:Skin lesions should be the optimal specimen type for detecting mpox virus, while other types of specimens can be used as alternatives or supplements.

The first locally acquired case in the Chinese mainland was reported on May 31, 2023, lagging behind other countries. In this study, we aimed to examine the early clinical and epidemiological characteristics of the earliest cases of Mpox in Beijing, China. Additionally, we investigated the sequence and transmission patterns of the Mpox virus (MPXV). We analyzed 37 reported cases of Mpox in Beijing from May 31, 2023 to June 21, 2023. The age range of the subjects was 24-51 years. Thirty-six cases (97.3%) were identified in men who have sex with men (MSM), and 19 cases (51.4%) tested positive for the human immunodeficiency virus. Thirty-three cases were symptomatic, while four were asymptomatic. Skin lesions were observed in 32 cases (97.0%), fever in 26 (78.8%), and swollen lymph nodes in 17 (51.5%). Rash typically appeared in the genital or perianal area 1-3 days before fever onset, with a minimum incubation period of 2 days. For individuals with skin rashes, the skin lesion samples showed 100% positivity and low Ct values. There were high oropharyngeal swab (75.8%) and blood (84.6%) positivity rates. All MPXV strains belonged to the B.1.3 branch of the West African lineage. These strains carried 76-86 nucleotide substitutions compared with the reference human MPXV genome, and genetic diversity was observed. Our findings provide the first insights into the landscape of early transmission of Mpox in Beijing and help inform policy formulation in the Chinese mainland.

Objective:To understand the molecular epidemiological characteristics of coxsackievirus A6 (CV-A6) associated with herpangina (HA) in Beijing from 2018 to 2020.Methods:The basic information and clinical symptoms of HA cases under 18 years old in the 16 sentinel hospitals in Beijing from 2018 to 2020 were collected. Enterovirus (EV) and CV-A6 nucleic acid were detected by real time RT-PCR, and the epidemiological characteristics of HA cases were analyzed by descriptive statistical methods. The CV-A6 VP1 region was amplified and sequenced. The maximum likelihood method was used to reconstruct the phylogenetic tree by IQtree software, and the sequence was used for phylogentic analysis.Results:From 2018 to 2020, a total of 2 937 HA cases were collected, including 1 373 EV positive cases. The overall positive rate was 46.75%. The CV-A6 positive cases accounted for 29.42% (404/1 373) of all positive cases. Among the CV-A6 positive cases, the sex ratio was 1.08:1. The peak of incidence was in autumn, and the main symptoms were herpes (93.32%, 377/404) and fever (86.39%, 349/404). All patients were mild cases. In this study, the genotype E of CV-A6 was newly defined. The phylogenetic analysis and nucleotide similarity analysis of 89 full-length VP1 nucleotide sequences of CV-A6 indicated that all cases belonged to D3 gene subtype.Conclusions:CV-A6 was one of the main pathogens of HA in Beijing from 2018 to 2020 and the dominant strains belonged to subtype D3. Routine surveillance of HA cases should be carried out to timely analyze the molecular evolutionary characteristics of CV-A6.

Objective:To analyze the epidemiological characteristics and spatial clustering of hand, foot, and mouth disease (HFMD) in Beijing from 2017 to 2019.Methods:The data of HFMD cases in Beijing from 2017 to 2019 were obtained from the National Notifiable Infectious Disease Reporting System of the Chinese Information System for Disease Control and Prevention. The population, temporal and spatial distributions of HFMD cases in Beijing from 2017 to 2019 was described based on SAS 9.4 software, and the spatial-temporal clustering of HFMD was assessed using SaTScan 9.5 software.Results:A total of 80 586 HFMD cases were reported in Beijing from 2017 to 2019, including 137 (0.17%) severe cases. The average annual incidence was 107.67/100 000. The male to female ratio was 1.48:1 (48 035/32 551). Districts with higher incidence were clustered in newly developed urban areas. Seven clustering areas were detected in the city and all occurred in 2018. The most possible clustering area occurred from June to August 2018 with Yongledian Town of Tongzhou district as the center, surrounded by 22 streets in 4 districts (Tongzhou District, Fangshan District, Daxing District and Chaoyang District).Conclusions:The incidence of HFMD in Beijing from 2017 to 2019 showed obvious temporal and spatial clustering. The cases were observed mainly in summer and autumn, and in suburbs and urban rural junction areas. Health education on HFMD should be strengthened in the new urban development area, to improve the awareness of HFMD prevention among the mobile population.

The incidence of multidrug-resistant Acinetobacter baumannii has posed a major challenge for clinical treatment. There is still a significant gap in understanding the mechanism causing multi-drug resistance (MDR). In this study, the genomes of 10 drug sensitive and 10 multi-drug resistant A.baumannii strains isolated from a hospital in China were sequenced and compared. The antibiotic resistance genes, virulence factors were determined and CRIPSR-Cas system along with prophages were detected. The results showed that MDR strains are significantly different from the drug sensitive strains in the CARD entries, patterns of sequences matching up to plasmids, VFDB entries and CRISPR-Cas system. MDR strains contain unique CARD items related to antibiotic resistance which are absent in sensitive strains. Furthermore, sequences from genomes of MDR strains can match up with plasmids from more diversified bacteria genera compared to drug sensitive strains. MDR strains also contain a lower level of CRISPR genes and larger amount of prophages, along with higher levels of spacer sequences. These findings provide new experimental evidences for the study of the antibiotic resistance mechanism of A. baumannii.

目的 对两例无明确新型冠状病毒肺炎(coronavirus disease 2019,COVID-19,以下简称新冠肺炎)流行病学史,经多次核酸检测确诊的新冠肺炎病例实验室确诊过程进行总结分析,为新冠病毒核酸检测提供经验.方法 收集北京市2020年1-2月两例无明确新冠肺炎流行病史,且经多次核酸检测确诊的新冠肺炎病例的流行病学、临床表现等资料和实验室检测结果进行回顾性分析.结果 病例A,2020年1月19日发热伴全身疼痛、头痛,先后就诊2家医院,发热和肺炎病情未缓解.发病前有京外旅行史,2020年1月22日患者收入A2医院隔离治疗,诊断为"肺炎待查"并上报为新冠肺炎疑似病例.当日采集样本送北京市疾病预防控制中心(CDC)实验室进行荧光RT-PCR检测,N基因阳性.按当时《新型冠状病毒肺炎防控方案(第二版)》规定,实验室要求继续采样.1月23日再次采集样本,荧光RT-PCR检测ORF1ab和N基因阳性,该病例为新冠肺炎确诊病例.病例B,2020年2月3日发热,先后就诊3家医院,发热伴全身疼痛、头晕头痛.患者于2月9日在B3医院发热门诊就诊,并单间隔离治疗,上报为新冠肺炎疑似病例.2月10日和11日分别采集样本送北京市CDC实验室进行荧光PCR检测,ORF1ab和N基因阴性,但2月10日 样本的N基因在反应后期显示出荧光值小于判定阈值线的微弱信号.2月12日再次采集样本检测,ORF1ab和N基因阳性,该病例为新冠肺炎确诊病例.结论 因新冠肺炎临床表现无特异性,实验室病原学的核酸检测非常重要;如果新冠肺炎疑似病例首次样本检测结果阴性或可疑,建议再次采集多种类样本进行检测,以便尽可能早诊断.

Acinetobacter baumannii is one of the main causes of nosocomial infections. Increasing numbers of multidrug-resistant Acinetobacter baumannii cases have been reported in recent years, but its antibiotic resistance mechanism remains unclear. We studied 9 multidrug-resistant (MDR) and 10 drug-susceptible Acinetobacter baumannii clinical isolates using Label free, TMT labeling approach and glycoproteomics analysis to identify proteins related to drug resistance. Our results showed that 164 proteins exhibited different expressions between MDR and drug-susceptible isolates. These differential proteins can be classified into six groups: a. proteins related to antibiotic resistance, b. membrane proteins, membrane transporters and proteins related to membrane formation, c. Stress response-related proteins, d. proteins related to gene expression and protein translation, e. metabolism-related proteins, f. proteins with unknown function or other functions containing biofilm formation and virulence. In addition, we verified seven proteins at the transcription level in eight clinical isolates by using quantitative RT-PCR. Results showed that four of the selected proteins have positive correlations with the protein level. This study provided an insight into the mechanism of antibiotic resistance of multidrug-resistant Acinetobacter baumannii.

Objective:To establish a simple method based on the results of first-generation sequencing for identifying mixed infection of enterovirus.Methods:Simulated mixed infection samples were constructed and sequenced by first-generation sequencing. The perl script was used to analyze the sequencing chromatograms to obtain the sequences of primary and secondary peaks. Local alignment search with blastn against local database of enteroviruses and global alignment with stretcher were carried out. The enterovirus genotyping results by the primary and secondary sequences were compared.Results:The script was compiled for automatic analysis and identification of mixed infection status based on the chromatograms of the first generation sequencing and for obtaining the nucleotide sequences of the two viruses. For mixed samples with secondary virus DNA content of over or equal to 65ng, all genotypes were recognized and identified correctly if the proportions of secondary virus in the mixed sample were moderate (over or equal to 12.5% and below or equal to 25.0%). For genotyping, local alignment was similar to global alignment but the results of local alignment were better if the viruses were mixed at the ratio of 1:1.Conclusions:The simple identification method for mixed infections of enterovirus established in this study can be used for rapid detection and typing of viruses causing hand, foot, and mouth disease.

Objective:To study the clinical features and epidemiological characteristics of the first local case of severe fever with thrombocytopenia syndrome (SFTS) on October 2021 in Beijing, so as to provide basis for formulating the prevention and control strategy.Methods:The epidemiological characters of the case was analyzed by epidemiological investigation methods. Real time fluorescent quantitative PCR and ELISA were used to detect nucleic acid of severe fever with thrombocytopenia syndrome virus (SFTSV) and antibodies against the virus. The vectors and host animals were also investigated.Results:The investigation results indicated that the patient haven’t leave from Beijing for many years. Nucleic acid of SFTSV and IgM antibody were detected in the serum sample and the viral load was 1.9×10 4 TCID 50/ml. The 5 ticks captured during vector survey were negative for SFTSV nucleic acid. The blood sample of the pet dog was also negative for both SFTSV nucleic acid and antibody against the virus. Conclusions:The SFTS case on October 2021 was the first local case reported in Beijing. Surveillance for SFTS and vectors should be strengthened.

目的 调查北京市鼠形动物巴尔通体感染状况和遗传特征.方法 采用夹夜法在北京市16个区捕获鼠形动物,使用PCR方法检测巴尔通体gltA基因,测序后进行系统发育树分析.结果 共采集7属9种鼠形动物样本448份,检测到巴尔通体阳性样本46份,总阳性率为10.3％,且阳性率在鼠种间、地区间和生境间的差异均具有统计学意义(x2鼠种=114.980,x2地区=22.133,x2生境=96.466,P均＜0.001).系统发育树分析显示,40份样本序列位于进化树上的8个不同分支,提示北京市鼠形动物巴尔通体感染存在遗传多样性.结论 巴尔通体在北京市鼠形动物中广泛存在,并具有遗传多样性,本地人群存在一定的感染风险.