恙螨体内汉坦病毒核酸的基因芯片检测

目的 建立快速、灵敏、特异的汉坦病毒基因芯片诊断方法。方法 根据发表的汉坦病毒属(HV)76-118株和R22株S基因核苷酸序列，设计引物和探针，制备寡核苷酸芯片。用CV3标记核苷和引物，运用不对称PCR技术制备单链荧光标记核苷酸片段，并与芯片上的寡核苷酸探针杂交，荧光扫描仪检测并分析信号。结果 研究制备的基因芯片能够检测汉坦病毒HTN型和SEO型病毒核酸的特异性荧光信号。结论 HV的基因芯片检测具有特异、灵敏、快速的优点。基因芯片的制备和检测技术的建立，可为肾综合征出血热等传染病的诊断和预防提供理想的方法。     

Acute rheumatic fever in adult patients

Acute rheumatic fever (ARF) is considered as a disorder of children, and attacks in adults are usually a recurrence of disease acquired in the child’s life. Although the incidence of ARF in children has a decreasing trend in developed countries, resurgent and sporadic epidemics still occur in adults. The first attacks of ARF in adult patients without a childhood history can lead to a diagnostic dilemma.A medical record review in adults at least 18 years of age with an arthralgia complaint fulfilling 2015 revised Jones criteria was performed from January 1, 2000 to December 31, 2019.Eleven ARF patients were identified, including 8 with initial attacks (6 females aged 26–42 years, 33.9 ± 5.3) and 3 pre-existing valvular heart disease with recurrent attacks (2 females aged 38–52 years, 45.0 ± 7.0). In addition to febrile pharyngitis and migratory polyarthritis in initial attacks, pericarditis was encountered in 1, valvulitis in 2, prolong PR interval in 3 and skin involvement in 2 patients with erythema marginatum and IgA vasculitis. All responded to antibiotics and nonsteroidal anti-inflammatory drugs therapy with normalized clinical and laboratory abnormalities, no new-onset carditis, and no recurrent disease during a long-term follow-up (3.8–19.8 years, 12.7 ± 5.4).A sporadic occurrence of adult ARF is observed in southern Taiwan. This disease should be considered by physicians for the differential diagnosis of febrile pharyngitis with arthritis and/or carditis in adults, even in areas with a low incidence of ARF.     

Epidemiology of Mosquito-Borne Viruses in Egypt: A Systematic Review

There are at least five common mosquito-borne viruses (MBVs) recorded in Egypt, including dengue virus (DENV), Rift Valley fever virus (RVFV), West Nile virus (WNV), Chikungunya virus, and Sindbis virus. Unexpected outbreaks caused by MBVs reflect the deficiencies of the MBV surveillance system in Egypt. This systematic review characterized the epidemiology of MBV prevalence in Egypt. Human, animal, and vector prevalence studies on MBVs in Egypt were retrieved from Web of Science, PubMed, and Bing Scholar, and 33 eligible studies were included for further analyses. The monophyletic characterization of the RVFV and WNV strains found in Egypt, which spans about half a century, suggests that both RVFV and WNV are widely transmitted in this nation. Moreover, the seropositive rates of DENV and WNV in hosts were on the rise in recent years, and spillover events of DENV and WNV to other countries from Egypt have been recorded. The common drawback for surveillance of MBVs in Egypt is the lack of seroprevalence studies on MBVs, especially in this century. It is necessary to evaluate endemic transmission risk, establish an early warning system for MBVs, and develop a sound joint system for medical care and public health for managing MBVs in Egypt.     

Dynamic Interactions of Post Cleaved NS2B Cofactor and NS3 Protease Identified by Integrative Structural Approaches

Diseases caused by flaviviruses such as dengue virus (DENV) and West Nile Virus (WNV), are a serious threat to public health. The flavivirus single-stranded RNA genome is translated into a polyprotein which is cleaved into three structural proteins and seven non-structural proteins by the viral and cellular proteases. Non-structural (NS) protein 3 is a multifunctional protein that has N-terminal protease and C-terminal helicase domains. The NS3 protease requires co-factor NS2B for enzymatic activity and folding. Due to its essential role in viral replication, NS2B-NS3 protease is an attractive target for antiviral drugs. Despite the availability of crystal structures, dynamic interactions of the N- and C-termini of NS2B co-factor have been elusive due to their flexible fold. In this study, we employ integrative structural approaches combined with biochemical assays to elucidate the dynamic interactions of the flexible DENV4 NS2B and NS3 N- and C-termini. We captured the crystal structure of self-cleaved DENV4 NS2B₄₇NS3 protease in post cleavage state. The intermediate conformation adopted in the reported structure can be targeted by allosteric inhibitors. Comparison of our new findings from DENV4 against previously studied ZIKV NS2B-NS3 proteins reveals differences in NS2B-NS3 function between the two viruses. No inhibition of protease activity was observed for unlinked DENV NS2B-NS3 in presence of the cleavage site while ZIKV NS2B-NS3 cleavage inhibits protease activity. Another difference is that binding of the NS2B C-terminus to DENV4 eNS2B₄₇NS3Pro active site is mediated via interactions with P4-P6 residues while for ZIKV, the binding of NS2B C-terminus to active site is mediated by P1-P3 residues. The mapping of NS2B N- and C-termini with NS3 indicates that these intermolecular interactions occur mainly on the beta-barrel 2 of the NS3 protease domain. Our integrative approach enables a comprehensive understanding of the folding and dynamic interactions of DENV NS3 protease and its cofactor NS2B.     

电视教材《登革热及其防治》的创作体会

结合电视教材《登革热及其防治》的创作过程,从选题、总体设计、稿本编写、素材收集和整理、动画制作、前期拍摄,以及后期编辑等各方面阐述了制作体会,同时探讨了如何促进和完善电视教材的设计与创作。     

Clustering of and Risk Factors for the Porcine High Fever Disease in a Region of Vietnam

Porcine high fever disease (PHFD) emerged in 2006 in China and spread to Vietnam. Little work has been carried out to investigate PHFD risk factors and space–time dynamics. To fill this gap, we investigated probable cases of PHFD at household level as the outcome. A study area, approximately 100 sq. km, was selected from a province of southern Vietnam that had reported the outbreak of PHFD in 2008. A survey was conducted in the study area to collect information about swine health problems during 2008. The questionnaire included three sections: general information, clinical signs of disease in pigs and production factors believed to be risk factors. Cases were defined at the household level and included interpretation of clinical signs in series. Logistic regression with a random intercept at the hamlet level was used to assess risk factors for PHFD at the household level. Spatial clustering was investigated using the D‐function and a Cuzick–Edward’s test. Spatial clusters were evaluated using a spatial relative risk surface and the spatial scan statistic using a Bernoulli model. Space–time clustering was explored using a space–time K‐function and Knox’s test. Space–time clusters were evaluated using a space–time permutation model in SaTScan. Of 955 households with questionnaire data, 33.4% were classified as cases. The statistical significance of space and space–time clustering differed between methods employed. The risk factors associated with occurrence of cases were higher numbers of sows and finishing pigs (log 2 transformed), receiving pigs from an external source and the interaction between using ‘water green crop’ (WGC) as pig feed and owning ducks with or without direct contact with pigs. The interaction between the presence of ducks and feeding WGC to pigs suggested the involvement of pathogens that might be present in water (environment) and could further replicate in or on ducks.     

Serological Assays Based on Recombinant Viral Proteins for the Diagnosis of Arenavirus Hemorrhagic Fevers

The family Arenaviridae, genus Arenavirus, consists of two phylogenetically independent groups: Old World (OW) and New World (NW) complexes. The Lassa and Lujo viruses in the OW complex and the Guanarito, Junin, Machupo, Sabia, and Chapare viruses in the NW complex cause viral hemorrhagic fever (VHF) in humans, leading to serious public health concerns. These viruses are also considered potential bioterrorism agents. Therefore, it is of great importance to detect these pathogens rapidly and specifically in order to minimize the risk and scale of arenavirus outbreaks. However, these arenaviruses are classified as BSL-4 pathogens, thus making it difficult to develop diagnostic techniques for these virus infections in institutes without BSL-4 facilities. To overcome these difficulties, antibody detection systems in the form of an enzyme-linked immunosorbent assay (ELISA) and an indirect immunofluorescence assay were developed using recombinant nucleoproteins (rNPs) derived from these viruses. Furthermore, several antigen-detection assays were developed. For example, novel monoclonal antibodies (mAbs) to the rNPs of Lassa and Junin viruses were generated. Sandwich antigen-capture (Ag-capture) ELISAs using these mAbs as capture antibodies were developed and confirmed to be sensitive and specific for detecting the respective arenavirus NPs. These rNP-based assays were proposed to be useful not only for an etiological diagnosis of VHFs, but also for seroepidemiological studies on VHFs. We recently developed arenavirus neutralization assays using vesicular stomatitis virus (VSV)-based pseudotypes bearing arenavirus recombinant glycoproteins. The goal of this article is to review the recent advances in developing laboratory diagnostic assays based on recombinant viral proteins for the diagnosis of VHFs and epidemiological studies on the VHFs caused by arenaviruses.     

Phylogenetic analysis using E2 gene of classical swine fever virus reveals a new subgenotype in China

Outbreaks of classical swine fever (CSF) have caused serious economic consequences in China. Phylogenetic analysis based on full-length E2 gene sequences showed that five classical swine fever virus (CSFV) isolates collected from Hunan province in 2011 and 2012, together with seven other isolates from neighboring provinces, Guangdong (5) and Guangxi (2), could be classified as a new subgenotype 2.1c, which may have been endemic in the south of China for at least fourteen years. Subgenotype 2.1c isolates share 90.2–94.9% and 89.9–93.8% nucleotide sequence similarity separately with those of subgenotype 2.1a and 2.1b in E2 gene, which are lower than the nucleotide identities between subgenotype 2.1a and 2.1b (91.1–95.7%). Further analysis based on a partial E2 gene sequence (216 nt) indicated that subgenotype 2.1c isolates are also circulating in Thailand. Alignment of E2 amino acid sequences showed that subgenotype 2.1c isolates exhibit a SPA → TPV substitution at positions 777 and 779 compared with subgenotypes 2.1a and 2.1b.