ABSTRACT
Agar gel precipitation test with cross-adsorbed immune sera was used for the antigenic differentiation of strains of tick-borne encephalitis virus (TBEV). Fifty strains of the Far East TBEV serotype and 46 strains of the Siberian (Aina) TBEV serotype were isolated from Ixodes persulcatus, which is the main vector of the above TBEV subtypes in the Asian and European parts of Russia. The fragment of the envelope protein gene was sequenced for TBEV strains. Sequences of new-group strains of the Siberian subtypes isolated from 3 patients with chronic TBE and from brain tissues of 4 deceased patients were determined. Lethal TBE outcomes were registered in Siberia (Irkutsk Region and Krasnoyarsk Territory) and in Russia's European part (Yaroslavl Region).
Subject(s)
Encephalitis Viruses, Tick-Borne/genetics , Encephalitis, Tick-Borne/virology , Amino Acid Sequence , Animals , Antigens, Viral/immunology , Birds/virology , Brain/virology , Chronic Disease , Encephalitis Viruses, Tick-Borne/classification , Encephalitis Viruses, Tick-Borne/isolation & purification , Encephalitis, Tick-Borne/mortality , Genes, Viral , Humans , Molecular Sequence Data , Rodentia/virology , Russia/epidemiology , Sequence Alignment , Serotyping , Ticks/virology , Viral Envelope Proteins/geneticsABSTRACT
Enteroviral uveitis is accompanied by intensive and long-term production of specific neutralizing antibodies. The antibody titer to the causative virus ECHO 19/K (Siberia, Krasnoyarsk, 1980-1981) was 1:1000-1:65,000 in 80% of children 5 to 6 1/2 years after the illness. In retrospective examinations of blood sera from children with the history of uveitis using a neutralization test with ophthalmotropic strains of ECHO 19 and ECHO 11 viruses, the ECHO-virus etiology of this disease was first established in 80 patients living in the European part of the country (Moscow, Leningrad, Volgograd, Krasnodar, Donetsk, etc) and in the Caucasus (Yerevan, Tbilisi, Baku). The epidemic process in uveitis is associated with the emergence and alternation of antigenic ECHO virus variants. Both in the Asian and European USSR the causative agent of uveitis in 1979-1983 was ECHO 19/K, in 1980-1987 ECHO 11/A, and in 1986-1989 ECHO 11/B virus. In 1979-1989, altogether over 800 cases of uveitis in children caused by ophthalmotropic variants of ECHO 19 and ECHO 11 viruses were detected in the Soviet Union.
