ABSTRACT
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.
Subject(s)
Animals , Humans , Arachnid Vectors , Virology , China , Encephalitis Viruses, Tick-Borne , Classification , Genetics , Encephalitis, Tick-Borne , Virology , Genome, Viral , Ixodes , Virology , Molecular Sequence Data , PhylogenyABSTRACT
<p><b>OBJECTIVE</b>To investigate the recent emerged endemic region of tick-borne encephalitis (TBE) regarding its natural reserves, in Charles Hilary, northern Xinjiang and to isolate and characterize the viral geographic strain.</p><p><b>METHODS</b>Using indirect fluorescent assay to detect tick-borne encephalitis virus (TBEV) specific IgG antibodies from serum of local residents including 2 unconfirmed viral encephalitis patients in 2011 spring-summer. Viruses were isolated from tick samples by inoculating BALB/c mice and BHK-21 cells. For phylogenetic analysis. TBEV NS1 gene fragments were detected by RT-PCR and then subjected to sequence alignment.</p><p><b>RESULTS</b>1760 ticks were captured from the fields to have found that Ixodes persulcatus were dominated among the tick population. Two viral encephalitis patients were diagnosed as TBEV infection. In addition, 35.4% (23/65) local residents were detected positive for presence of TBEV specific-IgG antibodies in serum. After inoculation, morbidity and mortality of BALB/c mice were 72.9% (70/96) and 55.7% (44/79), respectively. TBEV specific-fragments were amplified from brain tissue of dead mice and cells culture supernatant. NS1 sequence alignment showed that the viral isolates were clustered into TBEV far-eastern sub-type, phylogenetically, and were mostly close to the isolates from northeastern China (99%) and Russian strain (98%).</p><p><b>CONCLUSION</b>In this study, a new endemic loci of TBE was firstly described in Charles Hilary natural reserve, northern Xinjiang. TBEV geographic isolates belonged to TBEV far-eastern subtype while Ixodes persulcatus and Dermacentor silvarum played crucial roles for disease transition.</p>
Subject(s)
Adult , Animals , Female , Humans , Male , Mice , China , Epidemiology , Encephalitis Viruses, Tick-Borne , Genetics , Allergy and Immunology , Encephalitis, Tick-Borne , Epidemiology , Virology , RNA, Viral , GeneticsABSTRACT
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.
Subject(s)
Animals , Arachnid Vectors/virology , Base Sequence , DNA Primers/genetics , Encephalitis Viruses, Tick-Borne/classification , 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/geneticsABSTRACT
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.
Subject(s)
Adult , Aged , Female , Humans , Antibodies , Chickenpox , Collodion , Communicable Diseases , Encephalitis, Tick-Borne , Fever , Haemophilus influenzae type b , Hepatitis A , Hepatitis A Vaccines , Hepatitis B , Hepatitis B Vaccines , Immunization , Immunization Schedule , Influenza, Human , Korea , Meningococcal Vaccines , Military Personnel , Papilloma , Reinforcement, Psychology , Vaccination , Vaccines , VirusesABSTRACT
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.
Subject(s)
Adult , Aged , Female , Humans , Antibodies , Chickenpox , Collodion , Communicable Diseases , Encephalitis, Tick-Borne , Fever , Haemophilus influenzae type b , Hepatitis A , Hepatitis A Vaccines , Hepatitis B , Hepatitis B Vaccines , Immunization , Immunization Schedule , Influenza, Human , Korea , Meningococcal Vaccines , Military Personnel , Papilloma , Reinforcement, Psychology , Vaccination , Vaccines , VirusesABSTRACT
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.
Subject(s)
Adult , Aged , Animals , Humans , Communicable Diseases , Counseling , Developing Countries , Encephalitis , Encephalitis, Japanese , Encephalitis, Tick-Borne , Hepatitis A , Immunization , Korea , Meningococcal Vaccines , Plague , Rabies , Rabies Vaccines , Saudi Arabia , Typhoid Fever , Vaccination , Vaccines , Whooping Cough , Yellow Fever , Yellow Fever VaccineABSTRACT
A formalin inactivated Kyasanur forest disease (KFD) virus tissue culture vaccine produced by the health department of the State Government of Karnataka at Shimoga was administered in Shimoga, Uttar Kannada and Chikmangalur districts during 1990-92 KFD epidemic seasons. The selection of places for vaccination was based on the prevalence of KFD activity in previous years; villages adjacent to KFD affected areas and the villages from which mortality in monkeys was reported. A total of 284 villages was covered under vaccination; 26850 individuals received one dose whereas, 61302 received two doses of vaccine. No untoward reaction was observed in any of the vaccinees. In the 72 KFD affected villages there were 14 patients among 9072 and 10 among 21083 vaccinees receiving one and two doses respectively, whereas 325 patients were reported among 37373 unvaccinated individuals during the same period. In 1990-91 the number of males patients was more than females whereas, in 1991-92 the ratio was reserved. On analysis indicated that the vaccine has a highly significant protective effect.