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The nervous system and the eye
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
James A.R. Nicoll, William Stewart, Fiona Roberts
Arboviruses (arthropod-borne viruses) are RNA viruses transmitted from host to host by bloodsucking insects and multiply in both vertebrate and invertebrate hosts. Humans are not a natural host for any arbovirus but may become infected during periods of epizootic spread among the natural hosts (usually wild birds and small mammals). Severe forms of encephalitis in humans include St Louis encephalitis, which is mosquito-borne, and louping ill, due to a tick-borne virus.
Ticks
Published in Gail Miriam Moraru, Jerome Goddard, The Goddard Guide to Arthropods of Medical Importance, Seventh Edition, 2019
Gail Miriam Moraru, Jerome Goddard
The term tick-borne encephalitis (TBE) is generally used to describe disease entities caused by at least three subtypes of a flavivirus: European tick-borne encephalitis (TBEV-Eur), Siberian (TBEV-Sib), and Far Eastern (TBEV-FE). A couple of these agents, however, occur in the Western Hemisphere (see below). The three Old World TBE diseases differ in severity, with the Far Eastern form, sometimes known as Russian spring–summer encephalitis (RSSE), being the worst. In Central Europe, the typical case shows a biphasic course with an early, viremic, flulike stage, followed about a week later by the appearance of signs of meningoencephalitis.82 CNS disease is relatively mild, but occasional severe motor dysfunction and permanent disability occur. The case fatality rate is 1 to 5%.83 On the other hand, TBEV-FE is characterized by violent headache, high fever, nausea, and vomiting. Delirium, coma, paralysis, and death may follow; the mortality rate is about 25 to 30%. A recent report showed that new variants of TBE virus in Russia may produce a hemorrhagic syndrome.84,85 Another member of the TBE serocomplex is called louping ill—named after a Scottish sheep disease—which, in humans, also displays a biphasic pattern and is generally mild. As mentioned, the virus infects sheep; few cases are actually ever reported in humans.
Animal diseases
Published in Jim Cox, Iain Mungall, Rural Healthcare, 2017
Outbreaks of trichophyton ringworm, lice and mange (caused by sarcoptic or psoroptic mites) are usually associated with poor nutrition. Ticks (Ixodes ricinus) are common in parts of the country and may be vectors of disease such as ‘louping ill’ in sheep (caused by Cytoecetes phagocytophilia) and ‘tick-borne fever’ (caused by Ehrlichia ovis). Lyme disease (Borrelia burgdorferi) is not commonly recognised in domestic animals, perhaps partly due to the lack of the classic skin rash seen in man.
Interactomics and tick vaccine development: new directions for the control of tick-borne diseases
Published in Expert Review of Proteomics, 2018
Sara Artigas-Jerónimo, José De La Fuente, Margarita Villar
Vaccines represent one of the biggest advances regarding the improvement of human and animal health. In the last years, vaccines have been shown to be the most efficient, cost-effective, and environmentally friendly approach for the control of ticks and the prevention of TBDs, especially in regions with high risk of infection or with severe disease symptoms [4,19]. Unfortunately, mainly due to safety issues to date only tick vaccines based on cattle tick, Rhipicephalus microplus, BM86 or BM95 recombinant antigens have been commercialized for the control of tick infestations showing a dual effect on reducing the prevalence of several TBDs in cattle [20–22]. Other potential recombinant antigens have been identified and tested showing a variable range of protective efficacy against different tick species, but the effect on pathogen infection and transmission has been only reported in few of them [4,23–25]. Moreover, vaccines for the control of some of the most dangerous and widespread TBDs, such as tick-borne encephalitis, Spanish goat encephalitis, Lyme disease or borreliosis, Louping ill, and Crimean-Congo hemorrhagic fever, have been developed with various efficacy and safety ranges [26–29].
Low prevalence of tick-borne encephalitis virus antibodies in Norwegian blood donors
Published in Infectious Diseases, 2021
Åshild Marvik, Yngvar Tveten, Anne-Berit Pedersen, Karin Stiasny, Åshild Kristine Andreassen, Nils Grude
Interference caused by flavivirus cross-reactive antibodies, due to common antigenic sites within the E protein, is well documented with the ELISA method among several flaviviruses that infect humans, like Japanese encephalitis virus, dengue virus and yellow fever virus [38,43–45]. A comparative study of different commercial TBEV IgG-ELISA kits, including Enzygnost, revealed particularly specificity problems with dengue virus IgG [45]. In the current study, exposure to other flaviviruses, either through vaccination or undergone infections, were obtained. Two of the three donors with a history of dengue fever had a reactive TBEV IgG ELISA due to cross-reactivity. In addition, at least two other donors had a reactive ELISA due to vaccination against Japanese encephalitis and/or yellow fever. Thus, at least four cases of flavivirus cross-reactive antibodies were observed. Skarpaas et al. did not assess false-positive TBEV IgG ELISA results due to any flavivirus exposure, while Thortveit et al. obtained information about TBE and/or yellow fever vaccinations. According to the literature, and our observations, a history of dengue fever is an important flavivirus exposure to identify. Louping-ill virus (LIV) is another flavivirus transmitted by I. ricinus ticks and is antigenically closely related to TBEV [44]. LIV can cause encephalomyelitis of sheep and is mainly restricted to the British Isles. However, LIV infections in sheep have been reported in Norway although the last case was in 1991 [46,47]. LIV is a rare cause of human disease and no human cases have ever been reported in Norway [48]. Thus, at present, cross-reactivity due to LIV antibodies is not a current issue.