scholarly journals Modern aspects of epidemiology of ticks transmitted infections

2014 ◽  
Vol 19 (5) ◽  
pp. 26-31
Author(s):  
A. B Konkova-Reydman ◽  
L. V Ter-Bagdasaryan
Keyword(s):  
Genetic Polymorphism ◽  
Practical Problem ◽  
Natural Populations ◽  
Phenotypic Heterogeneity ◽  
Symbiotic Interactions ◽  
Tbe Virus ◽  
Natural Foci ◽  
New Ideas ◽  
Triple Infection ◽  
Reservoir Hosts

Modern literature data have changed our imaginations about the etiological "landscape" of the diseases arising after the suction biting of ticks. The possibility of transmitting mixt-infections by ticks has become an important scientific and practical problem. Ticks can be infected by the all 7 found pathogens (TBE virus, 3 species of Borrelia, Ehrlichia, Anaplasma, Babesia). Among ticks with the modified morphology monoinfected individuals occur 1.3 times, biinfected - 1.5 times more frequently, and the cases of triple infection appear twice more often than among normal cases. There were formed new ideas about genotypic and phenotypic heterogeneity of natural populations of tick-borne virus, there is discussed the heterogeneity of the genome and the pathogenic properties of the TBE virus. There was performed the analysis of literature data about the multifacetedness of the genetic polymorphism typical for the genus Borrelia in total, observed phenomena of the discrepancy of the spectrum of genospecies of Borrelia in natural foci and in biological materials from patients, complex antagonistic tolerant or symbiotic interactions between various intracellular and extracellular pathogens carried by ticks, in the vector's body, reservoir hosts and macroorganism.

Chapter 1: A Short History of TBE

2019 ◽  
Author(s):  
Olaf Kahl ◽  
Vanda Vatslavovna Pogodina ◽  
Tatyana Poponnikova ◽  
Jochen Süss ◽  
Vladimir Zlobin
Keyword(s):  
Ixodid Ticks ◽  
Human Pathogen ◽  
Short History ◽  
Tbe Virus ◽  
Natural Foci ◽  
History Of ◽  
Far Eastern ◽  
Former Ussr ◽  
Reservoir Hosts

TBE virus is a flavivirus and a prominent tick-borne human pathogen occurring in parts of Asia and Europe. The virus was discovered by Lev A. Zilber and co-workers in the former USSR during an expedition in the Far Eastern taiga under the most difficult conditions in 1937. They and members of a second expedition under the leadership of the Academician Evgeny N. Pavlovsky 1938 elucidated the basic eco-epidemiology of the virus. In their natural foci, TBE virus circulates between vectors, certain ixodid ticks, and some of their hosts, so-called reservoir hosts, mostly small mammals. Five different subtypes of TBE virus have been described to date.

Chapter 1: A short history of TBE

2021 ◽  
Author(s):  
Olaf Kahl ◽  
Vanda Vatslavovna Pogodina ◽  
Tatyana Poponnikova ◽  
Jochen Süss ◽  
Vladimir Zlobin
Keyword(s):  
Ixodid Ticks ◽  
Human Pathogen ◽  
Short History ◽  
Tbe Virus ◽  
Natural Foci ◽  
History Of ◽  
Far Eastern ◽  
Former Ussr ◽  
Reservoir Hosts

TBE virus is a flavivirus and a prominent tick-borne human pathogen occurring in parts of Asia and Europe. The virus was discovered by Lev A. Zilber and co-workers in the former USSR during an expedition in the Far Eastern taiga under the most difficult conditions in 1937. They and members of a second expedition under the leadership of the Academician Evgeny N. Pavlovsky 1938 elucidated the basic eco-epidemiology of the virus. In their natural foci, TBE virus circulates between vectors, certain ixodid ticks, and some of their hosts, so-called reservoir hosts, mostly small mammals. Five different subtypes of TBE virus have been described to date.

Chapter 1: A short history of TBE

2020 ◽  
Author(s):  
Olaf Kahl ◽  
Vanda Vatslavovna Pogodina ◽  
Tatyana Poponnikova ◽  
Jochen Süss ◽  
Vladimir Zlobin
Keyword(s):  
Ixodid Ticks ◽  
Human Pathogen ◽  
Short History ◽  
Tbe Virus ◽  
Natural Foci ◽  
History Of ◽  
Far Eastern ◽  
Former Ussr ◽  
Reservoir Hosts

TBE virus is a flavivirus and a prominent tick-borne human pathogen occurring in parts of Asia and Europe. The virus was discovered by Lev A. Zilber and co-workers in the former USSR during an expedition in the Far Eastern taiga under the most difficult conditions in 1937. They and members of a second expedition under the leadership of the Academician Evgeny N. Pavlovsky 1938 elucidated the basic eco-epidemiology of the virus. In their natural foci, TBE virus circulates between vectors, certain ixodid ticks, and some of their hosts, so-called reservoir hosts, mostly small mammals. Five different subtypes of TBE virus have been described to date.

TBE in Romania

2019 ◽  
Author(s):  
Lidia Chitimia-Dobler ◽  
Adriana Hristea ◽  
Wilhelm Erber ◽  
Tamara Vuković Janković
Keyword(s):  
Epidemiological Survey ◽  
Carpathian Mountains ◽  
Territorial Expansion ◽  
Tbe Virus ◽  
Natural Foci ◽  
Risk Areas

Based on an epidemiological survey performed, human TBE- virus neuroinfections may have an endemic emergent course, and natural foci are in full territorial expansion. Identified risk areas are Tulcea district, Transylvania, at the base of the Carpathian Mountains and the Transylvanian Alps.

Chapter 11: General epidemiology of TBE

2020 ◽  
Keyword(s):  
Eastern Siberia ◽  
Genetic Lineages ◽  
Phylogenetic Studies ◽  
Tick Borne Encephalitis ◽  
Natural Foci ◽  
Genetic Sequences ◽  
Tick Borne Encephalitis Virus ◽  
Almost All ◽  
Far Eastern ◽  
Reservoir Hosts

Tick-borne encephalitis virus (TBEV) exists in natural foci, which are areas where TBEV is circulating among its vectors (ticks of different species and genera) and reservoir hosts (usually rodents and small mammals). Based on phylogenetic studies, four TBEV subtypes (Far-Eastern, Siberian, European, Baikalian) and two putative subtypes (Himalayan and “178-79” group) are known. Within each subtype, some genetic lineages are described. The European subtype (TBEV-EU) (formerly known also as the “Western subtype”) of TBEV is prevalent in Europe, but it was also isolated in Western and Eastern Siberia in Russia and South Korea. The Far-Eastern subtype (TBEV-FE) was preferably found in the territory of the far-eastern part of Eurasia, but some strains were isolated in other regions of Eurasia. The Siberian (TBEV-SIB) subtype is the most common and has been found in almost all TBEV habitat areas. The Baikalian subtype is prevalent around Lake Baikal and was isolated several times from ticks and rodents. In addition to the four TBEV subtypes, one single isolate of TBEV (178-79) and two genetic sequences (Himalayan) supposed to be new TBEV subtypes were described in Eastern Siberia and China. The data on TBEV seroprevalence in humans and animals can serve as an indication for the presence or absence of TBEV in studied area.

Genetic Polymorphism in Natural Populations of Avena fatua and A. barbata

Nature ◽  
1969 ◽  
Vol 221 (5177) ◽  
pp. 276-278 ◽  
Author(s):  
D. R. MARSHALL ◽  
S. K. JAIN
Keyword(s):  
Genetic Polymorphism ◽  
Natural Populations ◽  
Avena Fatua

Epidemiology and genetics in the coevolution of parasites and hosts

1983 ◽  
Vol 219 (1216) ◽  
pp. 281-313 ◽  
Keyword(s):  
Genetic Diversity ◽  
Sexual Reproduction ◽  
Empirical Evidence ◽  
Population Biology ◽  
Natural Populations ◽  
Numerical Magnitude ◽  
Parasitic Infections ◽  
Genetic Studies ◽  
New Ideas ◽  
Host Parasite

Recent studies suggest that parasites (interpreted broadly to include viruses, bacteria, protozoans and helminths) may influence the numerical magnitude or geographical distribution of their host populations; most of such studies focus on the population biology and epidemiology of the host-parasite association, taking no explicit account of the genetics. Other researchers have explored the possibility that the coevolution of hosts and parasites may be responsible for much of the genetic diversity found in natural populations, and may even be the main reason for sexual reproduction; such genetic studies rarely take accurate account of the density- and frequency-dependent effects associated with the transmission and maintenance of parasitic infections. This paper aims to combine epidemiology and genetics, reviewing the way in which earlier studies fit into a wider scheme and offering some new ideas about host-parasite coevolution. One central conclusion is that ‘successful’ parasites need not necessarily evolve to be harmless: both theory and some empirical evidence (particularly from the myxoma-rabbit system) indicate that many coevolutionary paths are possible, depending on the relation between virulence and transmissibility of the parasite or pathogen.

scholarly journals Epidemiological Features of Combined Natural-Focal Infections

2017 ◽  
Vol 16 (5) ◽  
pp. 43-52 ◽  
Author(s):  
V. V. Shkarin ◽  
A. S. Blagonravova ◽  
E. M. Chumakov
Keyword(s):  
Russian Federation ◽  
Mixed Infection ◽  
Quantitative Estimation ◽  
Clinical Manifestations ◽  
Original Research ◽  
Epidemiological Features ◽  
Natural Foci ◽  
The Russian Federation ◽  
And Control ◽  
Reservoir Hosts

On the basis of literature data and results of own research in the article describes the features of the epidemiology of combined natural focal infections, their distribution in the Russian Federation, pathogenesis and clinical features to suit different combinations of pathogen agents. The data on the mixed infection of ticks by different agents in various combinations, as well as polyetiology infected of reservoir hosts Showing different variants of combined natural focal infections in humans caused by the associations of microorganisms, including up to five assiociants, as well as features of the pathogenesis and clinical manifestations Based on original research developed a method of a quantitative estimation the activity of combined natural foci and complex of measures on surveillance and control of combined natural focal infections.

scholarly journals A GENERAL MODEL TO ACCOUNT FOR ENZYME VARIATION IN NATURAL POPULATIONS

Genetics ◽  
1974 ◽  
Vol 76 (4) ◽  
pp. 837-848
Author(s):  
John H Gillespie ◽  
Charles H Langley
Keyword(s):  
Genetic Polymorphism ◽  
Gene Function ◽  
General Model ◽  
Natural Populations ◽  
Environmental Variation ◽  
Biochemical Evidence ◽  
Enzyme Variation ◽  
Variable Environments ◽  
Varying Environments ◽  
Spatially Varying

ABSTRACT Approximate conditions for genetic polymorphism in temporally and spatially varying environments are presented for loci which are intermediate at the level of fitness or at the level of gene function. The conditions suggest that polymorphism will be more likely in more variable environments while unlikely in constant environments. Biochemical evidence is presented to justify the assumption of heterozygote intermediacy. Observations on natural populations are cited which substantiate the claim that allozymic polymorphism is primarily due to selection acting on environmental variation in gene function.

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