MOLECULAR-GENETIC MONITORING AS THE BASIS OF MODERN EPIDEMIOLOGICAL SURVEILLANCE OF TICK-BORNE INFECTIONS

Molecular genetic monitoring of natural focal of tick-borne infections in the epidemic season of 2018 revealed infectiousness of ixodid ticks causative agents of tick-borne encephalitis (0.58% of cases), Lyme disease (31% of cases), human monocytic ehrlichiosis (1.6% of cases) and granulocytic anaplasmosis (3.9% of cases) is registered and also co-infections of ticks by these infections (2.9% of cases) is revealed in natural and anthropourgic foci (B. burgdorferi s.l.+A. phagocytophilum, B. burgdorferi s.l.+E. chaffeensis/E. muris and B. burgdorferi s.l.+tick-borne encephalitis virus). The major epidemiological importance of ticks of the species I. persulcatus is found, their share being 87,6%. The majority of patients being bitten by a tick were from the southern and southeast areas of Primorye. Contamination of ticks with Borrelia was revealed not only in I. persulcatus, but also in ticks of the Haemaphysalis and Dermacentor. The infectiousness of ticks of B. burgdorferi s.l. (42,3%), tick-borne encephalitis virus (7,7%) and A. phagocytophilum (15,4%) was highest on Russky Island.

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Verification of mono- and mixed contaminations transmitting agents tick-borne infections

Russian Clinical Laboratory Diagnostics ◽

10.18821/0869-2084-2020-65-10-659-664 ◽

2020 ◽

Vol 65 (10) ◽

pp. 659-664

Author(s):

A. L. Shutikova ◽

V. A. Lubova ◽

G. N. Leonova

Keyword(s):

Mixed Infection ◽

Laboratory Diagnosis ◽

Ixodid Ticks ◽

Mixed Infections ◽

Frequency Of Occurrence ◽

Epidemic Season ◽

Granulocytic Anaplasmosis ◽

Tick Borne Encephalitis ◽

Causative Agents ◽

Human Monocytic Ehrlichiosis

In the territory of the Primorsky region, the nosoareas of causative agents of tick-borne infections often coincide and lead to mixed infection of ticks, which causes the mixed pathology in humans . We investigated ixodid ticks taken from people during the epidemic season of 2019 for the spectrum of pathogens of transmissible infections to determine the degree of their mono- and mixed infection. 651 specimens of ixodid ticks investigated. RNA/DNA pathogens was determined by the method of polymerase chain reaction (PCR), TBEV antigen by ELISA. The presence in ticks of pathogens of the following diseases was detected: Lyme borreliosis (35.3%), tick-borne replasing fever (11.3%), human granulocytic anaplasmosis (2.6%), human monocytic ehrlichiosis (2.4%), tick-borne encephalitis (1.8%), tick-borne ricketsiosis (1.0%). As agents of mono-infections, the virus of TBE, ehrlichia, anaplasma and rickettsia in ticks occurred less frequently than in combination with other pathogens. A high frequency of occurrence B. burgdorferi s.l. in mono-infection detected (58.7%). B. miyamotoi has met evenly at ticks with mono- and mixed infections. Total mixed infection of ticks was 23.1%. Borrelia have been identified in all mixed cases. Variants of double combinations (95.5 % of cases from all mixed infections) were as follows: B. burgdorferi s. l. + A. phagocytophilum, B. burgdorferi s.l. + E. chaffeensis / E. muris, B. burgdorferi s.l. + TBEV, B. burgdorferi s.l. + R. heilongjiangensis, B. burgdorferi s.l. + B. miyamotoi. The most frequent combination was B. burgdorferi s.l. + B. miyamotoi (37.8% of all mixed infections). In triple infection of B. burgdorferi s.l. + A. phagocytophilum + TBEV and B. burgdorferi s.l. + A. phagocytophilum + B. miyamotoi, the frequency of occurrence for each combination was 2.2%. Given the above, a complex laboratory diagnosis of tick-borne infections in individuals who have been bitten by a tick is necessary, including the detection of all pathogens common in focal areas.

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Tick-Borne Encephalitis Virus Diversity in Ixodid Ticks and Small Mammals in South-Western Siberia, Russia

Vector-Borne and Zoonotic Diseases ◽

10.1089/vbz.2015.1834 ◽

2016 ◽

Vol 16 (8) ◽

pp. 541-549 ◽

Cited By ~ 13

Author(s):

Valentina N. Bakhvalova ◽

Galina S. Chicherina ◽

Olga F. Potapova ◽

Victor V. Panov ◽

Victor V. Glupov ◽

...

Keyword(s):

Small Mammals ◽

Western Siberia ◽

Encephalitis Virus ◽

Ixodid Ticks ◽

Virus Diversity ◽

Tick Borne Encephalitis ◽

Tick Borne Encephalitis Virus

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Properties of the tick-borne encephalitis virus population during persistent infection of ixodid ticks and tick cell lines

Ticks and Tick-borne Diseases ◽

10.1016/j.ttbdis.2017.07.008 ◽

2017 ◽

Vol 8 (6) ◽

pp. 895-906 ◽

Cited By ~ 12

Author(s):

Oxana A. Belova ◽

Alexander G. Litov ◽

Ivan S. Kholodilov ◽

Liubov I. Kozlovskaya ◽

Lesley Bell-Sakyi ◽

...

Keyword(s):

Cell Lines ◽

Persistent Infection ◽

Encephalitis Virus ◽

Ixodid Ticks ◽

Virus Population ◽

Tick Cell ◽

Tick Borne Encephalitis ◽

Tick Borne Encephalitis Virus

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Assessment of Epizootiological-Epidemiological Situation on Natural Focal Infections in Aleksandrovsk-Sakhalin Territory of the Sakhalin Region

Problems of Particularly Dangerous Infections ◽

10.21055/0370-1069-2014-3-11-15 ◽

2014 ◽

pp. 11-15

Author(s):

E. I. Andaev ◽

M. V. Chesnokova ◽

T. I. Borisova ◽

E. A. Vershinin ◽

S. A. Tatarnikov ◽

...

Keyword(s):

Molecular Genetic ◽

Genetic Material ◽

West Nile Fever ◽

Granulocytic Anaplasmosis ◽

Current State ◽

Tick Borne Encephalitis ◽

Natural Foci ◽

Tick Borne Encephalitis Virus ◽

Human Monocytic Ehrlichiosis ◽

Epidemiological Significance

Objective of the work was to carry out complex assessment of the current state of epizootic activity and epidemiological significance of the infectious disease natural foci in the Aleksandrovsk-Sakhalin territory of the Sakhalin Region. Trapped were 56 samples of small mammals in July, 2010; collected were 180 specimens of taiga tick imago, caught were 1000 specimens of mosquitoes. 223 samples of blood sera were taken from residents of the region. All the field data were tested to detect specific antibodies, antigens and genetic material of agents. Based on the results of epizootiological investigations, serological and molecular-genetic assays, demonstrated was the occurence of natural foci of leptospirosis, tularemia, tick-borne encephalitis, borreliosis, rickettsiosis, human granulocytic anaplasmosis, human monocytic ehrlichiosis, West Nile fever, Inco fever, Batai and Geto fevers, as well as HFRS with varying degree of activity manifestation in the territory of the region. Isolated was tick-borne encephalitis virus from mosquitoes.

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Different tick-borne encephalitis virus (TBEV) prevalences in unfed versus partially engorged ixodid ticks – Evidence of virus replication and changes in tick behavior

Ticks and Tick-borne Diseases ◽

10.1016/j.ttbdis.2012.05.005 ◽

2012 ◽

Vol 3 (4) ◽

pp. 240-246 ◽

Cited By ~ 33

Author(s):

Oxana A. Belova ◽

Ludmila A. Burenkova ◽

Galina G. Karganova

Keyword(s):

Virus Replication ◽

Encephalitis Virus ◽

Ixodid Ticks ◽

Tick Borne Encephalitis ◽

Tick Borne Encephalitis Virus

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Tick-borne encephalitis virus – a review of an emerging zoonosis

Journal of General Virology ◽

10.1099/vir.0.011437-0 ◽

2009 ◽

Vol 90 (8) ◽

pp. 1781-1794 ◽

Cited By ~ 269

Author(s):

K. L. Mansfield ◽

N. Johnson ◽

L. P. Phipps ◽

J. R. Stephenson ◽

A. R. Fooks ◽

...

Keyword(s):

Clinical Manifestations ◽

Northern China ◽

Encephalitis Virus ◽

Ixodid Ticks ◽

Ixodes Persulcatus ◽

Tick Borne Encephalitis ◽

Far Eastern Russia ◽

Tick Borne Encephalitis Virus ◽

Far Eastern

During the last 30 years, there has been a continued increase in human cases of tick-borne encephalitis (TBE) in Europe, a disease caused by tick-borne encephalitis virus (TBEV). TBEV is endemic in an area ranging from northern China and Japan, through far-eastern Russia to Europe, and is maintained in cycles involving Ixodid ticks (Ixodes ricinus and Ixodes persulcatus) and wild vertebrate hosts. The virus causes a potentially fatal neurological infection, with thousands of cases reported annually throughout Europe. TBE has a significant mortality rate depending upon the strain of virus or may cause long-term neurological/neuropsychiatric sequelae in people affected. In this review, we comprehensively reviewed TBEV, its epidemiology and pathogenesis, the clinical manifestations of TBE, along with vaccination and prevention. We also discuss the factors which may have influenced an apparent increase in the number of reported human cases each year, despite the availability of effective vaccines.

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Molecular Genetic Analysis of the Complete Genome of Tick-Borne Encephalitis Virus (Siberia Subtype): Modern Kolarovo-2008 Isolate

Problems of Particularly Dangerous Infections ◽

10.21055/0370-1069-2011-4(110)-44-48 ◽

2011 ◽

pp. 44-48 ◽

Cited By ~ 4

Author(s):

E. V. Chausov ◽

V. A. Ternovoy ◽

E. V. Protopopova ◽

S. N. Konovalova ◽

Yu. V. Kononova ◽

...

Keyword(s):

Amino Acid ◽

Nucleotide Sequence ◽

Complete Genome ◽

Molecular Genetic ◽

Molecular Genetic Analysis ◽

Encephalitis Virus ◽

Nucleotide Sequence Analysis ◽

Tick Borne Encephalitis ◽

Tick Borne Encephalitis Virus ◽

Siberian Subtype

Determined is the complete genome sequence of Kolarovo-2008 strain (Siberia subtype) of Tick-borne encephalitis virus (TBEV), isolated from a tick in the suburbs of the Tomsk city. Nucleotide sequence analysis testifies of the fact that the level of genetic differences within the Siberian subtype of TBEV amounts to 10 % of the nucleotide sequence and to 7 % of amino-acid sequence for certain virus genes. 3'-HTO of the genome of Siberian subtype has the highest rate of variability and the homology level ranging from 65 to 97 %. Kolarovo-2008 and Vasilchenko (isolated in Novosibirsk in 1969) strains have the highest level of genome homology. The level of dissimilarity between the two Tomsk strains is substantially higher: the total number of amino-acid substitutions in Tomsk Zausaev and Kolarovo-2008 strains equals to 124, and 3'HTO level of homology is 79 %. Identified genetic variability of the Siberian subtype of TBEV is of a great importance for further development and enhancement of tick-borne encephalitis virus diagnostics.

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