OBJECTIVE: Tick-borne encephalitis virus (TBEV) is an emerging pathogen in Europe and North Asia that causes tick-borne encephalitis (TBE). A simple, rapid method for detecting TBEV RNA is needed to control this disease. METHODS: A reverse-transcription recombinase-aided amplification (RT-RAA) assay was developed. This assay can be completed in one closed tube at 39 °C within 30 minutes. The sensitivity and specificity of RT-RAA were validated using non-infectious synthetic RNA representing a fragment of the NS5 region of the wild-type (WT) TBEV genome and the Senzhang strain. Additionally, 10 batches of tick samples were used to evaluate the performance of the RT-RAA assay. RESULTS: The analytical limit of detection of the assay was 20 copies per reaction of the TBEV synthetic transcript and 3 plaque-forming units (pfu) per reaction of TBEV titers. With the specific assay, no signal due to other arboviruses was observed. Of the 10 batches of tick samples obtained from the Changbai Mountains of China, three were TBEV-positive, which was consistent with the results of the quantitative real-time PCR assay. CONCLUSION A rapid, highly sensitive, specific, and easy-to-use method was developed for the detection of the TBEV Far-Eastern subtype.
Encephalitis Viruses, Tick-Borne ; genetics ; isolation & purification ; Nucleic Acid Amplification Techniques ; RNA, Viral ; analysis

Until the recent emergence/re-emergence of human-pathogenic viruses in ticks, tick-borne viruses have been neglected as causative agents of human disease (particularly in China). To gain insight into the diversity of tick-borne viruses in Xinjiang Uygur Autonomous Region (northwestern China), we conducted illumina deep sequencing-based screening for virus-derived small RNAs in field-collected Ixodes persulcatus ticks. We found 32, 631 unique virus-matched reads. In particular, 77 reads mapped to the tick-borne group within the genus of Flavivirus, and covered 3.8%-2.4% viral genomes. In addition, 32 unique reads were specific to the Siberian subtype of tick-borne encephalitis viruses (TBEV-Sib) which have never been reported in Chinese TBE loci. We confirmed the potential existence of TBEV-Sib by amplification (using reverse transcription-polymerase chain reaction) of genomic fragments from the envelope gene or 3' genomic terminus from the pools of examined ticks. Both sequences demonstrated high homology to TBEV-Sib strains attached geographically to southern Siberia with nucleotide identity of 97.2%-95.5% and aminoacid identity of 99.4%-98.3%, respectively. In conclusion, we report, for the first time, detection of TBEV-Sib in the natural TBE loci of China. These novel data may provide genetic information for further isolation and epidemiologic investigation of TBEV-Sib.
Animals ; Arachnid Vectors ; virology ; China ; Encephalitis Viruses, Tick-Borne ; classification ; genetics ; isolation & purification ; Encephalitis, Tick-Borne ; transmission ; virology ; Genome, Viral ; Humans ; Ixodes ; virology ; Molecular Sequence Data ; Phylogeny

Japanese encephalitis (JE) is a mosquito-borne zoonotic disease that affects approximately 50,000 people annually in Asia, causing 10,000 deaths. Considering the role of pigs as the virus-amplifying host and the economic loss in the swine industry, JE is an important disease for both public and animal health. A nationwide JE virus (JEV) vaccination program has been conducted annually for more than 30 years to prevent severe reproductive disorders in the Korean sow population. Remarkable progress in molecular biology has made it possible to analyze the genome of the vaccine strain at the nucleotide and amino acid levels. However, the scientific record of the current JEV veterinary vaccine has not been reported. Therefore, this article outlines the current JEV vaccine strain used in animals and discusses future directions for developing new veterinary JEV vaccines.
Animals ; Asia ; Asian Continental Ancestry Group* ; Encephalitis Viruses, Japanese ; Encephalitis, Japanese* ; Genome ; Humans ; Korea* ; Molecular Biology ; Swine ; Vaccination ; Vaccines* ; Zoonoses

In this review, we mainly focus on zoonotic encephalitides caused by arthropod-borne viruses (arboviruses) of the families Flaviviridae (genus Flavivirus) and Togaviridae (genus Alphavirus) that are important in both humans and domestic animals. Specifically, we will focus on alphaviruses (Eastern equine encephalitis virus, Western equine encephalitis virus, Venezuelan equine encephalitis virus) and flaviviruses (Japanese encephalitis virus and West Nile virus). Most of these viruses were originally found in tropical regions such as Africa and South America or in some regions in Asia. However, they have dispersed widely and currently cause diseases around the world. Global warming, increasing urbanization and population size in tropical regions, faster transportation and rapid spread of arthropod vectors contribute in continuous spreading of arboviruses into new geographic areas causing reemerging or resurging diseases. Most of the reemerging arboviruses also have emerged as zoonotic disease agents and created major public health issues and disease epidemics.
Africa ; Alphavirus* ; Animals, Domestic ; Arboviruses* ; Arthropod Vectors ; Asia ; Encephalitis ; Encephalitis Virus, Venezuelan Equine ; Encephalitis Virus, Western Equine ; Encephalitis Viruses ; Encephalomyelitis, Equine ; Epidemiology* ; Flaviviridae ; Flavivirus* ; Global Warming ; Humans ; Population Density ; Public Health ; South America ; Togaviridae ; Transportation ; Urbanization ; Zoonoses

OBJECTIVETo study the characteristics of viral spectrum and clinical features of children in pediatric intensive care unit (PICU).

METHODNasopharyngeal aspirate specimens (NPA) from 349 patients(1 from each) and 130 cerebrospinal fluids (CSF) specimens were collected from children who were admitted to the PICU of Second Affiliated Hospital of Shantou University Medical College. Additional 87 NPA specimens were collected from healthy children for routine examination on the physical examination center, and the clinical data were collected. Multiplex PCR was applied to detect 16 kinds of viruses from NPA and CSF. Fluorescence quantitative PCR was applied to detect 13 viruses from CSF and to analyze the clinical data of positive cases.

RESULTThere were 209 samples (59.9%) of the 349 NPA specimens were positive for viruses, which included 117 cases positive for human rhinovirus (HRV), 60 for respiratory syncytial virus (RSV), 20 for influenza virus A (Inf A), 10 for adenovirus (ADV), 6 for parainfluenza virus type 3(PIV-3), 6 for human Boca virus (HBoV), 5 for influenza virus C(Inf C), 4 for parainfluenza virus type 4(PIV-4), 4 for human coronavirus-HKU1/OC43, 3 for influenza virus B (Inf B), 3 for WU Polyomavirus (WUPyV), 2 parainfluenza virus type 1(PIV-1), 2 human metapneumovirus (HMPV) and 1 human coronavirus-NL63/229E. But none from 87 healthy controls were positive for any respiratory virus. Among the 130 CSF specimens, in 58 cases the diagnosis was viral encephalitis. There were 22 samples (37.9%) among the 58 CSF specimens positive for viruses, which included 14 enterovirus (EV), 3 human cytomegalovirus (HCMV), 2 mumps virus, 1 coxsackie virus A16 (Cox-A16), 1 herpes simplex virus (HSV) and 1 human rhinovirus (HRV). The total positive rate was 63.3% (221/349) . Co-infection by at least 2 viral pathogens under study was observed in 45 of the 349 patients (12.9% of the total number of cases, 20.4% of the positives cases). The commonest pathogens in co-infected samples were WUPyV (100%) and HMPV(100%). The positive rate of virus peaked in the first 6 months of life, the rate in boys were higher than in girls and the peak season was summer. The numbers of none serious cases in the virus positive group were less than those in the virus negative group while the numbers of extremely serious cases in the virus positive group were higher than in the virus negative group.

CONCLUSIONViral pathogen is a major cause of infectious disease in pediatric critical illnesses and virus infection may lead to severe illness.

Acute Disease ; Age Distribution ; Child ; Child, Preschool ; Coinfection ; virology ; Encephalitis, Viral ; epidemiology ; virology ; Female ; Humans ; Infant ; Influenza A virus ; isolation & purification ; Intensive Care Units, Pediatric ; Male ; Polymerase Chain Reaction ; RNA Viruses ; isolation & purification ; Respiratory Syncytial Viruses ; isolation & purification ; Respiratory Tract Infections ; epidemiology ; virology ; Rhinovirus ; isolation & purification ; Virus Diseases ; epidemiology ; virology

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the human polyomavirus JC virus. PML mainly occurs in immunocompromised patients. A 36-year-old man with no evidence of immunosuppresion presented seizures. MRI scans of brain showed multifocal lesions in the cerebral white matters. JC virus DNA was positive in the cerebrospinal fluid examined by JC virus PCR. We report a rare case of PML presenting as viral encephalitis that occurred in a healthy adult person.
Adult ; Brain ; Central Nervous System ; Demyelinating Diseases ; DNA ; Encephalitis, Viral ; Humans ; Immunocompromised Host ; JC Virus ; Leukoencephalopathy, Progressive Multifocal ; Magnetic Resonance Imaging ; Polymerase Chain Reaction ; Seizures ; Viruses

Several species of animals, including horses and pigs, can be infected with Japanese encephalitis virus (JEV). Wild boars (Sus scrofa) are also considered to be an effective amplifying host for JEV in wild environments. In this study, 288 blood samples were collected from wild boars in eight Korean provinces, and antibodies against JEV were detected using a virus neutralizing assay. The results showed that 66.0% (190/288) of wild boars in Korea had neutralizing antibodies against JEV. We found no significant differences in the seroprevalence of JEV among provinces (p > 0.05). The results indicate that wild boars in Korea have been exposed to JEV, suggesting that these boars may play an important role in amplifying and carrying JEV to other regions of Korea. The result of this study may be helpful for planning preventive measures.
Animals ; Antibodies ; Antibodies, Neutralizing ; Asian Continental Ancestry Group ; Encephalitis Virus, Japanese ; Encephalitis, Japanese ; Horses ; Humans ; Korea ; Lifting ; Seroepidemiologic Studies ; Sus scrofa ; Swine ; Viruses

Multiplex reverse transcription-polymerase chain reaction (mRT-PCR) is currently available in virus detection and defined as the simultaneous amplification of two or more DNA/RNA targets in a single reaction vessel. In this study, we attempted to modify the conventional mRT-PCR technique on a basis of GenomeLab Genetic Analysis System (GeXP). Initially, we optimized the analytical validation of the GeXP analyzer and its design of workflow and simultaneously detected eight arboviruses that related to epidemic encephalitis by verifying the specificity of mRT-PCR with Japanese encephalitis virus(JEV) cell cultures and positive strains identified previously and determining the sensitivity with in vitro-transcribed RNA of serial dilutions. The GeXP system after optimization could amplify the specific fragments related to the viruses and exposed specifically a total of 13 target genes out of eight types of arboviruses at the level of 10(2) copies/microL, and the findings suggest that the novel protocol we developed can be high-throughput and highly specific and sensitive as well as quickness in screening of the encephalitis viruses, and is promising in detection of encephalitis-associated viruses for molecular epidemiological studies.
Arboviruses ; genetics ; isolation & purification ; Encephalitis Virus, Japanese ; genetics ; Encephalitis Viruses ; genetics ; isolation & purification ; Reverse Transcriptase Polymerase Chain Reaction ; methods ; Sensitivity and Specificity

Since April 2009, outbreaks of the new influenza A (H1N1) virus have occurred worldwide. The spectrum of disease caused by H1N1 infection ranges from non-febrile, mild upper respiratory tract illness to severe or fatal pneumonia. Rapidly progressive respiratory diseases, such as acute respiratory distress syndrome and renal or multi-organ failure, have accounted for severely affected inpatients. Complex cases involving myocarditis, encephalitis, and myositis have been described. However, pulmonary air-leak syndrome, consisting of spontaneous pneumomediastinal emphysema, pneumothorax, and subcutaneous emphysema complicating pneumonia with the H1N1 virus, has not previously been reported in Korea. Here, we report a case of pulmonary air-leak syndrome complicating H1N1 infection that was resolved with an antiviral agent, high-flow oxygen, and fluid therapy.
Disease Outbreaks ; Emphysema ; Encephalitis ; Fluid Therapy ; Humans ; Influenza A Virus, H1N1 Subtype ; Influenza, Human ; Inpatients ; Korea ; Mediastinal Emphysema ; Myocarditis ; Myositis ; Oxygen ; Pneumonia ; Pneumothorax ; Respiratory Distress Syndrome, Adult ; Respiratory System ; Subcutaneous Emphysema ; Viruses

The prevalence of tick-borne encephalitis virus (TBEV) in southern Korea was determined by collecting ticks using tick drags. A total of 4,077 of 6,788 ticks collected were pooled (649 pools) according to collection site, species, and developmental stage and assayed for TBEV. The TBEV protein E and NS5 gene fragments were detected using RT-nested PCR in six pools of nymphs collected from Jeju Island (2,491 ticks). The minimum field detection rates for TBEV were 0.17% and 0.14% for Haemaphysalis longicornis and Haemayphysalis. flava nymphs, respectively. The 252 bp NS5 and 477 bp protein E gene amplicons were sequenced. Phylogenetic analysis showed that the NS5 and protein E genes of the Jeju strain were clustered with Western subtype (98.0% and 99.4% identity, respectively). The Western subtype of TBEV is endemic in Korea, including Jeju Island. The study of vector and zoonotic host susceptibility to TBEV is required to better understand its potential impact on public health.
Animals ; Arachnid Vectors/*virology ; Base Sequence ; DNA Primers/genetics ; Encephalitis Viruses, Tick-Borne/classification/*genetics ; Encephalitis, Tick-Borne/*epidemiology ; Molecular Sequence Data ; *Phylogeny ; Prevalence ; Republic of Korea/epidemiology ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; Ticks/*virology ; Viral Envelope Proteins/genetics