{"title":"Novel viral encephalitides associated with bats (Chiroptera)--host management strategies.","authors":"H Field, J Mackenzie, P Daszak","doi":"10.1007/978-3-7091-0572-6_9","DOIUrl":"https://doi.org/10.1007/978-3-7091-0572-6_9","url":null,"abstract":"<p><p>Several novel viruses recently described in bats of the genus Pteropus (sub-order Megachiroptera) in Australia and southeast Asia cause encephalitic disease in animals and humans. These viruses include Hendra virus and Nipah virus (genus Henipavirus, family Paramyxoviridae) and Australian bat lyssavirus (ABLV; genus Lyssavirus, family Rhabdoviridae). Broadly, strategies for disease prevention and control in the spillover host are directed at minimising direct or indirect contact with the natural host, improving farm-gate and on-farm biosecurity, and better disease recognition and diagnosis. Additional strategies for ABLV include the use of rabies vaccine for effective pre- and post-exposure prophylaxis in humans. Effective management strategies in the natural host are predicated on an understanding of the ecology of the disease in the natural host, and the identification and avoidance of factors putatively associated with emergence, such as habitat loss, land use change and demographic shifts. A possible future management strategy for ABLV in reservoir populations is immunisation using bait or plant-derived vaccination.</p>","PeriodicalId":77010,"journal":{"name":"Archives of virology. Supplementum","volume":" 18","pages":"113-21"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24498167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tick-borne encephalitis and the impact of vaccination.","authors":"F X Heinz, C Kunz","doi":"10.1007/978-3-7091-0572-6_18","DOIUrl":"https://doi.org/10.1007/978-3-7091-0572-6_18","url":null,"abstract":"<p><p>TBE virus is endemic in many parts of Europe and Northern Asia, and in these regions it causes more than 10,000 severe cases of central nervous system disease in humans each year. The virus is primarily transmitted to humans when infected ticks take a blood meal, but infections due to the consumption of unpasteurized milk, primarily from goats, occur in certain regions. Based on genetic analyses, three closely related subtypes can be distinguished and are designated European, Siberian, and Far Eastern subtype according to their primary geographic distribution. Consistent with their close antigenic relationships, immunization studies in animals have revealed a high degree of cross-protection between virus strains belonging to different subtypes. The commercially available vaccines in Europe consist of highly purified inactivated whole TBE virus. Austria is the country with the highest coverage of TBE vaccination (86% of the total population) and this has led to a dramatic reduction in the annual number of clinical cases and proves under field conditions that vaccination is an effective means for the prophylaxis of TBE.</p>","PeriodicalId":77010,"journal":{"name":"Archives of virology. Supplementum","volume":" 18","pages":"201-5"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24498700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D K Lvov, A M Butenko, V L Gromashevsky, A I Kovtunov, A G Prilipov, R Kinney, V A Aristova, A F Dzharkenov, E I Samokhvalov, H M Savage, M Y Shchelkanov, I V Galkina, P G Deryabin, D J Gubler, L N Kulikova, S K Alkhovsky, T M Moskvina, L V Zlobina, G K Sadykova, A G Shatalov, D N Lvov, V E Usachev, A G Voronina
{"title":"West Nile virus and other zoonotic viruses in Russia: examples of emerging-reemerging situations.","authors":"D K Lvov, A M Butenko, V L Gromashevsky, A I Kovtunov, A G Prilipov, R Kinney, V A Aristova, A F Dzharkenov, E I Samokhvalov, H M Savage, M Y Shchelkanov, I V Galkina, P G Deryabin, D J Gubler, L N Kulikova, S K Alkhovsky, T M Moskvina, L V Zlobina, G K Sadykova, A G Shatalov, D N Lvov, V E Usachev, A G Voronina","doi":"10.1007/978-3-7091-0572-6_7","DOIUrl":"https://doi.org/10.1007/978-3-7091-0572-6_7","url":null,"abstract":"<p><p>Studies of the interactions of vertebrates, viruses and arthropod vectors of these viruses were monitored in terms of different ecological groups of viruses transmitted by mosquitoes and ticks in Northern Eurasia in an area encompassing more than 15 million km2. About 90 viruses were isolated, including 24 new to science. Newly recognized infections of vertebrates, including humans, were described. Many unusual epidemic situations were analysed. Permanent efforts were established to prevent bioterrorist activities and their consequences. Extensive epidemic outbreaks of West Nile fever (WNF; i.e., fever caused by West Nile virus) and Crimean-Congo hemorrhagic fever (CCHF) with unusual high mortality appeared in the last four years in southern Russia. We determined infection rates in humans, domestic and wild animals, mosquitoes and ticks from natural and synanthropic biocenoses [Editorial note: \"synanthropic\" means, roughly, all species living with (c.f. lice, fleas) or near people, such as in houses (c.f. house mice), parks (c.f. Rattus spp.), and the like, rather like \"peridomestic\", but not strictly so; \"biocenosis\" is the biome, the \"totality of living populations in a particular habitat, which itself is only a part of the ecosystem\".]. CCHF virus strains were phylogenetically similar to strains isolated in this area 35 years ago but different from Central-South-Asian and African strains. Before the outset of the current emergence of epidemic WNF, three genetic variants of this virus had been isolated in USSR, two African and one Indian. Phylogenetic analysis of complete genome sequences of epidemic strains demonstrated considerable similarity to strains from USA and Israel and differences from strains isolated in the same USSR areas 20-30 years before. In addition to strains of genotype 1, we isolated strains of second and third lineages and a strain of a fourth genetic variant. Nucleotide differences of these strains from all three genotypes was about 30%. The emerging WNF situation in Russia for the last 4 years probably has been the result of not only natural and social factors, but also to introduction of more virulent strains or by evolution of the virus.</p>","PeriodicalId":77010,"journal":{"name":"Archives of virology. Supplementum","volume":" 18","pages":"85-96"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/978-3-7091-0572-6_7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24498165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Persistent infection and suppression of host response by alphaviruses.","authors":"I Frolov","doi":"10.1007/978-3-7091-0572-6_12","DOIUrl":"https://doi.org/10.1007/978-3-7091-0572-6_12","url":null,"abstract":"<p><p>Alphaviruses cause chronic noncytopathic infection in mosquito cells and develop a highly cytopathic infection in a wide variety of cells of vertebrate origin. Upon infection, alphaviruses modify cellular processes to meet the virus needs for propagation. Downregulation of translation and transcription caused by viral infection appears to reduce interferon (IFN) and cytokine gene expression and allows more efficient dissemination of infection. Alphaviruses with mutations in nonstructural protein nsP2 can become less cytopathic and capable of persisting in some vertebrate cell lines for a number of passages. nsP2 likely functions as an important regulator of virus-host cell interactions and plays a significant role in suppressing the antiviral response. Mammalian cells having no defects in type I IFN system react to replication of the nsP2 viral mutants by more efficient activation of IFN and IFN-dependent genes and are capable of eliminating established alphavirus infection. Blocking of IFN-alpha/beta signaling makes mouse fibroblasts unable to stop replication of Sindbis virus (SINV) with mutated nsP2 and leads to persistent infection. Downregulation of transcription and translation during alphavirus infection are quite independent events, and both probably are involved in inhibition of the antiviral response.</p>","PeriodicalId":77010,"journal":{"name":"Archives of virology. Supplementum","volume":" 18","pages":"139-47"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/978-3-7091-0572-6_12","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24498694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Eaton, P. J. Wright, L. Wang, O. Sergeyev, W. Michalski, K. Bossart, C. Broder
{"title":"Henipaviruses: recent observations on regulation of transcription and the nature of the cell receptor.","authors":"B. Eaton, P. J. Wright, L. Wang, O. Sergeyev, W. Michalski, K. Bossart, C. Broder","doi":"10.1007/978-3-7091-0572-6_10","DOIUrl":"https://doi.org/10.1007/978-3-7091-0572-6_10","url":null,"abstract":"","PeriodicalId":77010,"journal":{"name":"Archives of virology. Supplementum","volume":"18 1","pages":"122-31"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/978-3-7091-0572-6_10","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"51386693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Semliki forest virus infection of laboratory mice: a model to study the pathogenesis of viral encephalitis.","authors":"J K Fazakerley","doi":"10.1007/978-3-7091-0572-6_16","DOIUrl":"https://doi.org/10.1007/978-3-7091-0572-6_16","url":null,"abstract":"<p><p>Semliki Forest virus (SFV) infection of the laboratory mouse provides an experimental system to study the pathogenesis of viral encephalitis. Following extraneural inoculation the virus is efficiently neuroinvasive and crosses the blood-brain barrier to initiate perivascular foci of infection in neurons and oligodendrocytes. The outcome of infection ranges from clinically unapparent mild encephalitis to fatal panencephalitis. SFV infections of the developing nervous system are always highly destructive and are generally fatal. In contrast, SFV infections of the mature nervous system can result in persistent infection with no apparent cell loss. This dramatic difference is attributable to developmental changes in the interactions between virus and CNS cells. Antibody responses clear the systemic infection and control the CNS infection. CD8+ T-cells are required to generate the lesions of inflammatory demyelination which can be a feature of the neuropathology. This article reviews the pathogenesis of SFV encephalitis, describing the neuropathology and the mechanisms which underlie it and which may be fundamental to many viral encephalitides.</p>","PeriodicalId":77010,"journal":{"name":"Archives of virology. Supplementum","volume":" 18","pages":"179-90"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24498698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Emergence and virulence of encephalitogenic arboviruses.","authors":"D E Griffin, A P Byrnes, S H Cook","doi":"10.1007/978-3-7091-0572-6_3","DOIUrl":"https://doi.org/10.1007/978-3-7091-0572-6_3","url":null,"abstract":"<p><p>Each arbovirus that causes encephalitis is geographically restricted by the availability of appropriate vectors and reservoir hosts. These viruses evolve regionally by recombination, reassortment and point mutation and can \"emerge\" as causes of human encephalitis through extension to new geographic regions or by selection of more virulent or more efficiently transmitted virus variants. The properties of arboviruses that result in encephalitis involve efficient replication in peripheral tissues after initiation of infection, production of a viremia, entry into the central nervous system and efficient replication in neurons with spread to additional populations of neurons. Many of these steps are determined by properties of the envelope glycoproteins responsible for cellular attachment, but changes in noncoding regions of the genome, as well as in other structural and nonstructural proteins, also contribute to neurovirulence.</p>","PeriodicalId":77010,"journal":{"name":"Archives of virology. Supplementum","volume":" 18","pages":"21-33"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/978-3-7091-0572-6_3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24497567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Diagnosis of zoonotic viral encephalitis.","authors":"G Vernet","doi":"10.1007/978-3-7091-0572-6_21","DOIUrl":"https://doi.org/10.1007/978-3-7091-0572-6_21","url":null,"abstract":"<p><p>Human infections by zoonotic encephalitis viruses are usually asymptomatic or symptoms are not specific to these viruses. Some of them have high mortality and morbidity rates and most often no specific treatment exist. This emphasizes the need for a precise identification of arboviruses in clinical specimens from humans and animals. Because these diseases are frequent in developing countries and tend to emerge or re-emerge in others, diagnostic tools must detect the broadest possible range of viruses with a high sensitivity and this is a key factor for surveillance, control of transmission and prevention through vaccination. In countries with limited diagnostic infrastructures, low-cost and easy-to-use tests are required. The diagnosis of arboviral encephalitis has been significantly improved in the recent years. Sensitive ELISA assay to detect antibodies against many arboviruses in serum or CSF are commercially available and can be used to detect early infections. Immunochromatographic rapid tests for the detection of specific IgM that could be used on fingertip blood would be valuable tools in developing countries. A limitation of these serologic assays is their lack of specificity as many arboviruses are antigenically related. Virus isolation or molecular assays from different human or animal tissues are also important diagnostic tools. Molecular assays have been extensively described in the recent years. They are very sensitive and have the advantage over cell culture that specimen transportation is less critical. Real-time detection has even improved sensitivity and reduced time-to-result. Although the utility of molecular assays for the detection of arboviruses in mosquito pools has been demonstrated, an extensive validation of their pertinence in clinical settings is still required. The use of DNA-microarrays may further extend the range of viruses that can be detected in a single test and allow isolates typing for epidemiology purposes.</p>","PeriodicalId":77010,"journal":{"name":"Archives of virology. Supplementum","volume":" 18","pages":"231-44"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/978-3-7091-0572-6_21","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24498015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Neurovirulence and host factors in flavivirus encephalitis--evidence from clinical epidemiology.","authors":"T Solomon, P M Winter","doi":"10.1007/978-3-7091-0572-6_14","DOIUrl":"https://doi.org/10.1007/978-3-7091-0572-6_14","url":null,"abstract":"<p><p>Japanese encephalitis virus (JEV) and West Nile virus (WNV) provide some of the most important examples of emerging zoonotic viral encephalitides. For these flaviviruses, only a small proportion of those infected develop clinical features, and these may range from a non-specific flu-like illness to a severe fatal meningoencephalitis, often with Parkinsonian features, or a poliomyelitis-like flaccid paralysis. The factors governing the clinical presentations, and outcome of flavivirus infections are poorly understood, but studies have looked at viral virulence determinants and the host immune response. Previous studies on JEV have suggested that the distribution of the four genotypes across Asia may relate to the differing clinical epidemiology (epidemic disease in the north, endemic disease in the south). However, new data based on the complete nucleotide sequence of a virus representing one of the oldest lineages, and phylogenetic analyses of all JEV strains for which genetic data are available, suggest that the distribution is best explained in terms of the virus' origin in the Indonesia-Malaysia region (where all genotypes have been found), and the spread of the more recent genotypes to new geographical areas. Clinical studies have shown that innate immunity, as manifested by interferon alpha levels, is important in JEV and other flaviviruses, but treatment with interferon alpha did not improve the outcome. A failure of the humoral immune response, is associated with death from encephalitis caused by JEV and WNV. Cellular immunity has been less well characterized, but CD8+ and CD4+ T cells are thought to be important.</p>","PeriodicalId":77010,"journal":{"name":"Archives of virology. Supplementum","volume":" 18","pages":"161-70"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/978-3-7091-0572-6_14","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24498696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A novel principle of attenuation for the development of new generation live flavivirus vaccines.","authors":"R M Kofler, F X Heinz, C W Mandl","doi":"10.1007/978-3-7091-0572-6_17","DOIUrl":"https://doi.org/10.1007/978-3-7091-0572-6_17","url":null,"abstract":"<p><p>The genus Flavivirus includes a number of important human pathogens that impose major health problems in large regions of the world. The emergence of flaviviruses in new geographic regions (e.g., West Nile virus in North America) and rapid socioeconomic changed in many developing countries where flaviviruses such as dengue virus and Japanese encephalitis virus and endemic demand the development of new vaccines against these diseases. Using tick-borne encephalitis virus as a model we have established a new method to generate attenuated flavivirus strains that may be useful for generating cost-effective and safe live vaccines. This method relies on the specific introduction of deletions into one of the structural proteins, the capsid protein C. These deletions remove parts or all of an internal stretch of hydrophobic amino acid residues that probably is involved in virion assembly. We observed that remarkably long deletions were tolerated, yielding viable viral mutants that were highly attenuated in the mouse model but efficiently induced protective immunity. Biochemical analyses suggested that attenuation was caused by an assembly defect of infectious virions but the mutants produced ample amounts of non-infections subviral particles. The generation of viable mutants with deletions longer that 16 amino acid residues depended on additional, spontaneously emerging mutations within protein C that increased the hydrophobicity of the mutant protein. Although the second-site mutations increased infectivity, they did not restore neuroinvasiveness. Mouse experiments demonstrated excellent safety and immunogenicity profiles for these mutants.</p>","PeriodicalId":77010,"journal":{"name":"Archives of virology. Supplementum","volume":" 18","pages":"191-200"},"PeriodicalIF":0.0,"publicationDate":"2004-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24498699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}