2012年-2016年晋中市流感监测结果分析

目的分析2012年-2016年晋中市流感病毒毒株变化特点和流行特征,旨在为该市流感防控工作提供科学依据。方法通过中国流感监测信息系统统计晋中市2家哨点监测医院的流感样病例数据,采用实时荧光定量PCR法进行核酸检测。结果 2012年-2016年晋中市共采集流感样病例标本5,535份,经核酸检出阳性1,290份,阳性率为23.31%。其中新甲型H1N1占16.36%,季节性H3N2占41.86%,乙型占41.78%。2012年、2014年、2015年以季节性H3N2流行为主,2013年以新甲型H1N1流行为主,2016年以乙型流行为主。2012年10月-2013年4月、2013年11月-2014年4月、2014年10月-2015年5月、2015年11月-2016年5月各呈现一个流行峰。5年来不同年龄组毒株检出的阳性率以10岁以下组最高,占35.58%;其次为10岁-20岁组(19.53%)和50岁-100岁组(15.97%)。结论流感毒株主要在冬春季和夏秋季较为活跃,以儿童和青少年为主,应加强流感的监测和疾病防控。

Epidemiology and genetic characteristics of coxsackievirus A16 associated with hand-foot-and-mouth disease in Yantai city,China in 2018-2021

In 2008,China launched a national surveillance system for hand‐foot‐and‐mouth disease(HFMD).Several million cases of HFMD are reported every year,coxsackievirus A16(CVA16)was the leading cause of HFMD epidemic in Yantai city,China in recent years,but the information of epidemiology and molecular characterization of CVA16 in Yantai is limited.The aim of this study is to investigate the epidemiological characteristics and pathogenic spectrum of HFMD,and most importantly,the molecular characterization of CVA16 in Yantai from 2018 to 2021.A total of 2,000 clinical samples were collected in Yantai city from 2018 to 2021 and the enterovirus typing was performed using real‐time reverse transcriptase–polymerase chain reaction(qRT‐PCR).VP1 coding regions of 41 CVA16 isolates were amplified and Sanger sequenced,and phylogenetic analysis was performed.During the study period,HFMD became prevalent from May to August each year.It peaked in June and declined in September.The incidence was highest in children aged 1 to 5 years,while more common in males than females.1,617 out of 2,000 clinical collection of samples were tested positive for enterovirus.Among them,614 were identified as CVA16,45 were enterovirus A71(EV A17),and 958 were other enterovirus serotypes.All 41 CVA16 strains belonged to the Bla and B1b genotypes.Homology analysis showed that 41 CVA16 isolates shared 83.2%–100%nucleotide and 93.7%–100%amino acid similarity among themselves.The results of this study update molecular epidemiology of CVA16 and provide a reference for HFMD prevention and control.

A one-step reverse-transcription recombinase aided PCR assay for the rapid and sensitive detection of human enteroviruses

Human enteroviruses(HEVs)include many different types that cause a wide range of diseases,and an effective method of genus-level identification has therefore significant clinical implications.However,quantitative real-time reverse transcription polymerase chain reaction(qRT-PCR),the gold-standard method,still has shortfalls in diagnostic sensitivity and timeliness.Here we established a one-step real-time reverse-transcription recombinase-aided PCR assay(RT-RAP)to detect HEV fragment within an hour.The RT-RAP assay showed a detection limit of 5 copies/μL using recombinant plasmids and was extensively verified using 15 HEV strains.Among 15 types of HEV(species A-C),the sensitivity of RT-RAP was approximately 2-8 folds lower than that of the qRT-PCR in 9 types,and no-cross reaction with other viruses was observed.RT-RAP was further applied to analyze CSF and fecal specimens;the clinical performance demonstrated that the RT-RAP and the commercial qRT-PCR kit provided consistent results.These results indicated that RT-RAP assay may be a promising approach for rapid and sensitive detection of HEV.

Spatial distribution and pollution assessment of heavy metals in urban soils from southwest China

To identify the concentrations and sources of heavy metals, and to assess soil environmental quality, 63 soil samples were collected in Yibin City, Sichuan Province, China. Mean concentrations of As, Pb, Zn, and Cu were 10.55, 61.23, 138.88 and 56.35 mg/kg, respectively. As concentrations were comparable to background values, while Pb, Zn, and Cu concentrations were higher than their corresponding background values. Industrial areas exhibited the highest concentrations of As, Pb, Zn, and Cu, while the lowest concentrations occurred in parks. Statistical analysis was performed and two cluster groups of metals were identified with Pb, Zn, and Cu in one group and As in the other. Spatial distribution maps indicated that Pb, Zn, and Cu were mainly controlled by anthropogenic activities, whereas As could be mainly accounted for by soil parent materials. Pollution index values of As, Pb, Zn, and Cu varied in the range of 0.24-1.93, 0.66-7.24, 0.42-4.19, and 0.62-5.25, with mean values of 0.86, 1.98, 1.61, and 1.78, respectively. The integrated pollution index （IPI） values of these metals varied from 0.82 to 3.54, with a mean of 1.6 and more than 90% of soil samples were moderately or highly contaminated with heavy metals. The spatial distribution of IPI showed that newer urban areas displayed relatively lower heavy metal contamination in comparison with older urban areas.

Activation of Anti-tumor Immune Response by Ablation of HCC with Nanosecond Pulsed Electric Field

Locoregional therapy is playing an increasingly important role in the non-surgical management of hepatocellular carcinoma(HCC).The novel technique of non-thermal electric ablation by nanosecond pulsed electric field has been recognized as a potential locoregional methodology for indicated HCC.This manuscript explores the most recent studies to indicate its unique anti-tumor immune response.The possible immune mechanism,termed as nano-pulse stimulation,was also analyzed.

Identification of Histoplasma causing an unexplained disease cluster in Matthews Ridge, Guyana

Here,we report the identification of Histoplasma causing an unexplained disease cluster in Matthews Ridge,Guyana.In March 2019,14 employees of Chongqing Bosai Mining Company,China,working in a manganese mining of Guyana,had unexplained fever,and two of them died.We obtained lung and brain tissues as well as the blood samples from the two deceased cases(patient No.1 and 2),and bronchoscopy lavages and cerebrospinal fluid samples from one severe case(patient No.3),respectively.All samples were tested by pathological examination,high-throughput sequencing,and real-time PCR.Pathological detection showed the presence of spore-like structures in the lung tissue of patient No.1,indicating a fungal infection in this patient.Nanopore sequencing identified the existing of H.capsulatum in the lung tissue sample within 13 h.Next-generation sequencing identified specific fragments of H.capsulatum in all of the samples tested(lung,brain and blood serum from the deceased cases,and plasma from the severe case).Real-time PCR assays did not reveal any viral infection related to transmission from bat feces.We conclude that H.capsulatum was the causative pathogen of this disease cluster based on epidemiologic,clinical,pathological and nucleic acid evidence.

Field Evaluation of a Duplex RT-RAA Assay for Rapid Detection of SARS-CoV-2--Hebei Province,China,January 2021

Introduction:Recently,a local cluster epidemic has occurred in Shijiazhuang City,Hebei Province.Failure to promptly identify patients with fever in rural areas was the major reason for this epidemic.Methods:We presented the field evaluation of a new real-time reverse transcription recombinase-aided amplification(RT-RAA)kit incorporating an endogenous internal control in a single-tube format,completed at the Hebei CDC from January 17,2021 to January 27,2021.Results:We evaluated the diagnostic performance of RT-RAA assay using automatic extracted RNA of 808 clinical samples.Compared with reverse transcriptase real-time quantitative PCR(qRT-PCR),RT-RAA kit achieved 92.41%sensitivity,98.78%specificity and a 96.29%coincidence rate,demonstrating an excellent agreement between the RTRAA assay and qRT-PCR assay.Furthermore,58 samples were extracted using a manual extraction method within 5 minutes,but only samples with high nucleic acid concentration(cycle threshold value not higher than 32)could be stably detected.Discussion:The RT-RAA is more suitable to meet the needs of rapid,sensitive,and accurate detection in community-level medical institutions.

Enhancement of a recombinase-aided amplification assay using betaine and pullulan

Background:Nucleic acid amplification enhancers suitable for use in a recombinase-aided amplification(RAA)assay were studied for the first time,and amplification of a long-fragment(509 bp)was initially explored.Methods:Using recombinant plasmids and clinical samples,RAA fluorescence and basic methods were used to evaluate the efficacy.The fluorescence method was evaluated by threshold time and fluorescence value,and the basic method was characterized by 2%agarose gel electrophoresis.Results:Taking a previously established RAA assay for HPV18 as an example,we demonstrated that the addition of 0.2 M,0.4 M,and 0.6 M betaine and 10%pullulan could enhance the RAA.The new RAA assays with betaine and pullulan were named B-RAA and P-RAA,respectively.Using the B-RAA and P-RAA fluorescence methods,the threshold time values could be shortened by 1.72-2.32 minutes and 2.60 minutes,respectively,and the fluorescence values could be enhanced by 8847.25-9094.37 mv and 5250 mv,respectively.Using the basic method,the sensitivity could be increased 10-fold.We successfully amplified a long-fragment of 509 bp using a P-RAA assay with a sensitivity of 102 copies/μL(compared with 103 copies/μL in the RAA assay).Conclusions:Thus,we concluded that betaine and pullulan are effective additives to enhance the sensitivity of RAA assays.