scholarly journals Pathogens Manipulating Tick Behavior—Through a Glass, Darkly

Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 664
Author(s):  
Giovanni Benelli

Pathogens can manipulate the phenotypic traits of their hosts and vectors, maximizing their own fitness. Among the phenotypic traits that can be modified, manipulating vector behavior represents one of the most fascinating facets. How pathogens infection affects behavioral traits of key insect vectors has been extensively investigated. Major examples include Plasmodium, Leishmania and Trypanosoma spp. manipulating the behavior of mosquitoes, sand flies and kissing bugs, respectively. However, research on how pathogens can modify tick behavior is patchy. This review focuses on current knowledge about the behavioral changes triggered by Anaplasma, Borrelia, Babesia, Bartonella, Rickettsia and tick-borne encephalitis virus (TBEV) infection in tick vectors, analyzing their potential adaptive significance. As a general trend, being infected by Borrelia and TBEV boosts tick mobility (both questing and walking activity). Borrelia and Anaplasma infection magnifies Ixodes desiccation resistance, triggering physiological changes (Borrelia: higher fat reserves; Anaplasma: synthesis of heat shock proteins). Anaplasma infection also improves cold resistance in infected ticks through synthesis of an antifreeze glycoprotein. Being infected by Anaplasma, Borrelia and Babesia leads to increased tick survival. Borrelia, Babesia and Bartonella infection facilitates blood engorgement. In the last section, current challenges for future studies are outlined.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Philipp Kohler ◽  
Hulda R. Jonsdottir ◽  
Lorenz Risch ◽  
Pietro Vernazza ◽  
Rahel Ackermann-Gäumann ◽  
...  

AbstractCertain immunizations including vaccination against tick-borne encephalitis virus (TBEV) have been suggested to confer cross-protection against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Within a prospective healthcare worker (HCW) cohort, we assessed the potentially protective role of anti-TBEV antibodies against SARS-CoV-2 infection. Among 3352 HCW, those with ≥ 1 previous TBEV vaccination (n = 2018, 60%) showed a reduced risk of SARS-CoV-2 seroconversion (adjusted odds ratio: 0.8, 95% CI: 0.7–1.0, P = 0.02). However, laboratory testing of a subgroup of 26 baseline and follow-up samples did not demonstrate any neutralizing effect of anti-TBEV antibodies against SARS-CoV-2 in live-virus neutralization assay. However, we observed significantly higher anti-TBEV antibody titers in follow-up samples of participants with previous TBEV vaccination compared to baseline, both TBEV neutralizing (p = 0.001) and total IgG (P < 0.0001), irrespective of SARS-CoV-2 serostatus. Based on these data, we conclude that the observed association of previous TBEV vaccination and reduced risk of SARS-CoV-2 infection is likely due to residual confounding factors. The increase in TBEV follow-up antibody titers can be explained by natural TBEV exposure or potential non-specific immune activation upon exposure to various pathogens, including SARS-CoV-2. We believe that these findings, although negative, contribute to the current knowledge on potential cross-immunity against SARS-CoV-2 from previous immunizations.


1974 ◽  
Vol 45 (3) ◽  
pp. 209-214 ◽  
Author(s):  
T. I. Dzhivanyan ◽  
V. A. Lashkevich ◽  
G. G. Bannova ◽  
E. S. Sarmanova ◽  
M. V. Chuprinskaya ◽  
...  

Author(s):  
Joon Young Song

Although no human case of tick-borne encephalitis (TBE) has been documented in South Korea to date, surveillance studies have been conducted to evaluate the prevalence of tick-borne encephalitis virus (TBEV) in wild ticks.


Author(s):  
Jana Kerlik

The former Czechoslovak Republic was one of the first countries in Europe where the tick-borne encephalitis virus (TBEV) was identified.


Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.


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.


Author(s):  
E.V. Molchanova ◽  
D.N. Luchinin ◽  
A.O. Negodenko ◽  
D.R. Prilepskaya ◽  
N.V. Boroday ◽  
...  

The paper presents data from the monitoring studies’ results of arbovirus infections transmitted by mosquitoes in the Volgograd region. West Nile virus antigen (WNV) in 9 samples, Tahyna virus in one sample, Batai virus in two samples were detected in the study of 110 samples of field material (blood-sucking mosquitoes) by ELISA test. Antibodies to WNV in 16.58 percent of the samples, to tick-borne encephalitis virus in 1.08 percent, to viruses of the California serogroup and Ukuniemi in 1.09 percent, to the virus Sindbis in 2.17 percent were detected as a result of the study of blood serum samples from donors in the Volgograd region. Thus, we obtained data on the probable presence of the Batai, Sindbis, Ukuniemi and Californian serogroup viruses along with the circulation of WNV on the territory of the Volgograd region.


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