Objective: To summarize the clinical characteristics, diagnosis and treatment of forest encephalitis, and provide basis for revising relevant diagnostic criteria. Methods: From January to December 2020, the clinical characteristics, diagnosis and treatment of forest encephalitis cases in the data of China National Knowledge Infrastructure (CNKI) and Wanfang Chinese journals from 2009 to 2020 were retrospectively analyzed. The measurement data are expressed in Mean±SD, numbers, and the counting data of gender, region and occupation are expressed in numbers and composition ratio. Descriptive analysis of relevant data is carried out. Results: There were 1 153 confirmed cases of forest encephalitis reported in domestic literature, including 910 males and 243 females. Age: 16-78 years old; Cases were mainly distributed in Jilin Province, Inner Mongolia Autonomous Region and Heilongjiang Province. The cases included forest rangers (112/518), freelancers (104/518) and loggers (88/518). The common symptoms and signs were fever 81.2% (936/1153), headache 70.3% (811/1153), meninges irritation 29.0% (334/1153), vomiting 25.3% (292/1153), nausea 21.8% (251/1153), etc. Only 48.1% (555/1153) of the patients obtained positive pathogenic test results from blood and/or cerebrospinal fluid specimens. 42.1% (485/1153) had definite diagnosis grade, 354 cases were mild, 58 cases were moderate, and 73 cases were severe. Among 730 patients with forest encephalitis who received complete treatment, 511 cases were cured, 148 cases were improved, 48 cases were not cured, and 23 cases died. Conclusion: The epidemic of forest encephalitis has strict regional, seasonal and occupational characteristics. Early diagnosis and treatment can reduce the mortality and disability rate.
Male ; Female ; Humans ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Aged ; Retrospective Studies ; Encephalitis, Tick-Borne ; Encephalitis/epidemiology* ; Headache ; Fever

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

No abstract available.
Encephalitis, Tick-Borne*

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

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

Biomedical Research ; China ; Encephalitis, Tick-Borne ; Humans

In order to determine the characteristics and genotypes of E protein genes of tick-borne encephalitis (TBE) virus strains DXAL-5, 12,13,16,18, 21 isolated from Ixodes persulcatus in the Northeast of China, cDNA synthesis of E protein genes of the six DXAL strains was performed using RT-PCR, and the E protein genes were cloned and sequenced. The results showed that the nucleotide sequence of E protein gene of the six DXAL strains was 1488 bp in length respectively and the length of predicted protein was 496 aa respectively. Sequence comparison of E protein genes among the six DXAL strains and the reference TBE virus strains showed that the six DXAL strains were more homologous to Far Eastern subtype strains than to Siberian subtype strains or European subtype strains. And the majority of subtype-determining amino acid sites of the six DXAL strains belonged to TBE virus Far Eastern subtype. Phylogenetic analysis of protein E showed that the six DXAL strains were all within the clade containing Far Eastern subtype strains. The new strains had higher identities and closer phylogenetic relationships with Senzhang strain, so we speculate that this vaccine strain still have good protection against the new TBE virus isolates. In the A, B and C antigenic domains of protein E, the six DXAL strains had different degrees of amino acid changes. These mutations were likely to affect the function of E protein.
Amino Acid Sequence ; Animals ; Base Sequence ; China ; DNA, Complementary ; chemistry ; genetics ; Encephalitis Viruses, Tick-Borne ; classification ; genetics ; isolation & purification ; Mice ; Molecular Sequence Data ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Alignment ; Sequence Analysis, DNA ; Viral Envelope Proteins ; chemistry ; genetics

In 2006, the annual number of Koreans traveling internationally increased to 11 million. With this increased number of Koreans traveling to developing countries, various infectious diseases have been reported to be imported into Korea. Immunization is an important tool for the prevention of such diseases. Vaccination offered to international travelers is divided into 3 categories, i.e., obligatory vaccination, vaccines against diseases with an increased risk in developing countries, and routine vaccination. Vaccination that is obligatory for travelers includes yellow fever vaccine for travelers entering yellow fever-endemic areas and meningococcal vaccination for pilgrims traveling to Saudi Arabia. Recent reports of the adverse event following yellow fever vaccination, i.e., vaccine-associated viscerotropic disease, pose a caution in the administration of yellow fever vaccine to the elderly or individuals with thymic diseases. Protein-conjugated meningococcal vaccines are generally preferred; however, polysaccharide vaccines are also effective in short-term travelers. The vaccinations recommended for the health of travelers include administration of hepatitis A (HAV), meningococcal, typhoid, rabies, tick-borne encephalitis, and plague vaccines. As many young Korean adults lack immunity against hepatitis A, the administration of the HAV vaccine is recommended for all Korean individuals in their 20s and all Korean seronegative individuals in their 30s. The risk of acquiring typhoid fever is high among travelers traveling to the rural areas of developing countries for 2 weeks or more. The rabies vaccine may be recommended for travelers traveling for longer than 3 months and animal handlers. Both tick-borne encephalitis and plague are rarely encountered among Korean travelers; furthermore, vaccines for these diseases are not available in Korea. As Japanese encephalitis is endemic in Korea, vaccination against encephalitis is not essential for Korean adults. Pre-travel counseling is an important opportunity for catch-up vaccination of healthy travelers who missed routine vaccinations.
Adult ; Aged ; Animals ; Communicable Diseases ; Counseling ; Developing Countries ; Encephalitis ; Encephalitis, Japanese ; Encephalitis, Tick-Borne ; Hepatitis A ; Humans ; Immunization ; Korea ; Meningococcal Vaccines ; Plague ; Rabies ; Rabies Vaccines ; Saudi Arabia ; Typhoid Fever ; Vaccination ; Vaccines ; Whooping Cough ; Yellow Fever ; Yellow Fever Vaccine

In 2007, the Korean Society of Infectious Diseases recommended an immunization schedule for adults residing in Korea. This recommendation includes four categories: standard immunization for healthy persons, supplementary immunization for persons with underlying illnesses, recommendations for health-care personnel and for international travelers. The Standard Immunization Schedule consists of universal vaccination (tetanus-diphtheria/tetanus-diphtheria-pertussis (Td/Tdap); hepatitis A vaccine for persons aged 20s; human papilloma virus vaccine for women under 26 years old; meningococcal vaccine for military recruits and college students in dormitories; influenza vaccination for persons aged 50 years or more and pregnant women; and pneumococcal vaccination for persons aged 65 years or more) and catch-up vaccination (hepatitis A vaccine for persons aged 30s; hepatitis B vaccine, varicella and MMR vaccines for persons who have uncertain specific immunities). The Supplementary Immunization Schedule recommends 4 vaccines, i.e., pneumococcal, influenza, meningococcal, and Haemophilus influenzae type b, appropriate to the underlying illnesses, and confirmation of the presence of antibodies to hepatitis A and hepatitis B. The Recommendation for Health-Care Personnel includes universal vaccination (influenza and pertussis) and catch-up vaccination (hepatitis B, measles-mumps-rubella and varicella for seronegative health-care personnel). The Recommended Immunization for International Travelers focuses reinforcement of vaccinations for healthy persons and includes certain immunizations necessary for international travel (yellow fever, meningococcal, plaque, tick-borne encephalitis, and cholera). These guidelines can be seen at www.ksid.or.kr.
Adult ; Aged ; Antibodies ; Chickenpox ; Collodion ; Communicable Diseases ; Encephalitis, Tick-Borne ; Female ; Fever ; Haemophilus influenzae type b ; Hepatitis A ; Hepatitis A Vaccines ; Hepatitis B ; Hepatitis B Vaccines ; Humans ; Immunization ; Immunization Schedule ; Influenza, Human ; Korea ; Meningococcal Vaccines ; Military Personnel ; Papilloma ; Reinforcement (Psychology) ; Vaccination ; Vaccines ; Viruses

In 2007, the Korean Society of Infectious Diseases recommended an immunization schedule for adults residing in Korea. This recommendation includes four categories: standard immunization for healthy persons, supplementary immunization for persons with underlying illnesses, recommendations for health-care personnel and for international travelers. The Standard Immunization Schedule consists of universal vaccination (tetanus-diphtheria/tetanus-diphtheria-pertussis (Td/Tdap); hepatitis A vaccine for persons aged 20s; human papilloma virus vaccine for women under 26 years old; meningococcal vaccine for military recruits and college students in dormitories; influenza vaccination for persons aged 50 years or more and pregnant women; and pneumococcal vaccination for persons aged 65 years or more) and catch-up vaccination (hepatitis A vaccine for persons aged 30s; hepatitis B vaccine, varicella and MMR vaccines for persons who have uncertain specific immunities). The Supplementary Immunization Schedule recommends 4 vaccines, i.e., pneumococcal, influenza, meningococcal, and Haemophilus influenzae type b, appropriate to the underlying illnesses, and confirmation of the presence of antibodies to hepatitis A and hepatitis B. The Recommendation for Health-Care Personnel includes universal vaccination (influenza and pertussis) and catch-up vaccination (hepatitis B, measles-mumps-rubella and varicella for seronegative health-care personnel). The Recommended Immunization for International Travelers focuses reinforcement of vaccinations for healthy persons and includes certain immunizations necessary for international travel (yellow fever, meningococcal, plaque, tick-borne encephalitis, and cholera). These guidelines can be seen at www.ksid.or.kr.
Adult ; Aged ; Antibodies ; Chickenpox ; Collodion ; Communicable Diseases ; Encephalitis, Tick-Borne ; Female ; Fever ; Haemophilus influenzae type b ; Hepatitis A ; Hepatitis A Vaccines ; Hepatitis B ; Hepatitis B Vaccines ; Humans ; Immunization ; Immunization Schedule ; Influenza, Human ; Korea ; Meningococcal Vaccines ; Military Personnel ; Papilloma ; Reinforcement (Psychology) ; Vaccination ; Vaccines ; Viruses