RESUMO
The list of animal viruses has been frequently added of new members raising permanent concerns to virologists and veterinarians. The pathogenic potential and association with disease have been clearly demonstrated for some, but not for all of these emerging viruses. This review describes recent discoveries of animal viruses and their potential relevance for veterinary practice. Dogs were considered refractory to influenza viruses until 2004, when an influenza A virus subtype H3N8 was transmitted from horses and produced severe respiratory disease in racing greyhounds in Florida/USA. The novel virus, named canine influenza virus (CIV), is considered now a separate virus lineage and has spread among urban canine population in the USA. A new pestivirus (Flaviviridae), tentatively called HoBi-like pestivirus, was identified in 2004 in commercial fetal bovine serum from Brazil. Hobi-like viruses are genetically and antigenically related to bovine viral diarrhea virus (BVDV) and induce similar clinical manifestations. These novel viruses seem to be widespread in Brazilian herds and have also been detected in Southeast Asia and Europe. In 2011, a novel mosquito-borne orthobunyavirus, named Schmallenberg virus (SBV), was associated with fever, drop in milk production, abortion and newborn malformation in cattle and sheep in Germany. Subsequently, the virus disseminated over several European countries and currently represents a real treat for animal health. [...] Finally, the long time and intensive search for animal relatives of human hepatitis C virus (HCV) has led to the identification of novel hepaciviruses in dogs (canine hepacivirus [CHV]), horses (non-primate hepaciviruses [NPHV] or Theiler's disease associated virus [TDAV]) and rodents. For these, a clear and definitive association with disease is still lacking and only time and investigation will tell whether they are real disease agents or simple spectators.
O número de vírus animais cresce continuamente, causando preocupação permanente a virologistas e veterinários. O potencial patogênico e associação com doença tem sido claramente demonstrado para alguns - mas não para todos - vírus emergentes. Esse artigo apresenta uma breve revisão das recentes descobertas de vírus animais e a sua potencial relevância para saúde animal. Cães eram considerados refratários aos vírus da influenza até 2004, quando um vírus influenza A subtipo H3N8 foi transmitido de equinos e causou doença respiratória severa em cães galgos na Flórida/EUA. O novo vírus, denominado vírus da influenza canina (CIV), agora considerado uma linhagem distinta do vírus da influenza equina, disseminou-se na população canina urbana dos EUA. Um novo Pestivirus (Flaviviridae) - provisoriamente denominado pestivírus Hobi-like - foi identificado em 2004 em soro fetal bovino importado do Brasil. Os vírus Hobi-like são genética e antigenicamente relacionados com o vírus da diarreia viral bovina (BVDV) e induzem manifestações clínicas semelhantes. A sua origem e distribuição são desconhecidas, mas estão aparentemente disseminados no rebanho brasileiro e já foram identificados no sudeste asiático e na Europa. Em 2011, um novo buniavírus transmitido por mosquitos, denominado vírus Schmallemberg (SBV), foi associado com febre, redução da produção de leite, abortos e malformações fetais em bovinos e ovinos da Alemanha. [...] Finalmente, a longa e intensiva busca por vírus animais relacionados ao vírus da hepatite C humana (HCV) tem levado a identificação de "novos" pestivírus em cães (canine hepacivirus [CHV]), equinos (hepacivirus de não-primatas [NPHV] ou vírus associado à doença de Theiler [TDAV]) e em roedores. Para estes, uma associação clara e definitiva com doença ainda não foi demonstrada e apenas tempo e investigação irão dizer se são patógenos reais ou apenas espectadores.
Assuntos
Animais , Doenças Transmissíveis Emergentes/veterinária , Seleção Genética/genética , Gyrovirus/genética , Hepacivirus/genética , Alphainfluenzavirus/genética , Orthobunyavirus/genética , Pestivirus/genética , Vírus da Hepatite E/genéticaRESUMO
Os vírus Influenza A infectam um largo espectro de hospedeiros e causam epidemias anuais. São vírus com alta variabilidade genética e RNA segmentado, que podem sofrer rearranjos entre os genes de diferentes vírus. Em 2006, foram analisadas 521 amostras de crianças menores de 5 anos atendidas no HU-USP e 25 foram positivas para Influenza A, sendo H3N2 o mais prevalente (68%). Cinco genes de 18 amostras foram seqüenciados e obtivemos 13 sequencias de HA, 12 da NP, 12 de NA, 14 da M e 10 da NS. Verificou-se a presença de várias mutações, especialmente na HA e NA, que favoreceram a substituição da cepa vacinal naquele ano. Todas as amostras H3N2 apresentaram sítios de resistências aos inibidores da M2. Diferentes linhagens circularam no mesmo ano, tanto de H1 como de H3, favorecendo rearranjos entre elas. Foram verificados, também rearranjos envolvendo os genes da HA e NP, indicando o complexo mecanismo de evolução desses vírus e enfatizando a necessidade de monitoramento da circulação e caracterização de seus genes.
Influenza A virus infects a wide range of hosts and cause annual outbreaks. RNA segmented virus has high genetic variability and may have rearrangements between the genes of different viruses. In 2006, 521 samples of children younger than 5 years were analyzed and 25 tested positive for Influenza A virus, of which the subtype H3N2 is the most prevalent (68%). Five genes of 18 samples were sequenced and 13 sequences of HA, 12 of NP, 14 of M and 10 of NS obtained were. The presence of this several mutations, especially in the HA and NA genes probably helped the replacement of the vaccine strain in that year. All H3N2 subtype samples showed points of resistance to M2 inhibitors. The phylogenetic analysis revealed the circulation of different lineages in the same year, for both H1 and H3, and the presence of two rearrangements involving the HA and NP genes. These results indicate the influence of rearrangements in the evolution of the virus and emphasize the need for monitoring of circulation and characterization of genes.
Assuntos
Humanos , Criança , Infecções por Orthomyxoviridae/genética , Alphainfluenzavirus/genética , OrthomyxoviridaeRESUMO
Os Influenzavirus podem ser classificados de acordo com suas glicoproteínas externas hemaglutinina (HA) e neuraminidase (NA), ambas apresentando alta variabilidade genética e antigênica. No presente estudo foi realizada análise molecular do gene HA, do vírus influenza A (IA) em amostras colhidas de crianças e lactentes com sintomatologia respiratória atendidas no Hospital Universitário da Universidade de São Paulo (USP), durante os anos de 1995 a 2006. Um total de 3.009 amostras foram analisadas por duplex RT-PCR e 4,38% (n=132) foram positivas, sendo 12,1% (n=16) Influenza B e 87,9% (n=116) IA, das quais 9% (n=9) eram H1N1, 91% (n=91) eram H3N2 e 13,8% (n=16) não foram subtipadas. A região HA1 do gene HA de 39 amostras foi sequenciada e as sequências comparadas com as cepas vacinais e circulantes dos respectivos anos. A região de ligação ao receptor foi conservada em todas as amostras e foram verificadas alterações de aminoácidos principalmente nos sítios antigênicos e arredores. No geral, as cepas vacinais foram compatíveis com as circulantes em São Paulo.
The Influenzavirus can be classified according to their external glycoproteins hemagglutinin (HA) and neuraminidase (NA), both showing high genetic and antigenic variability. In the present study was carried out molecular analysis of the HA gene of influenza A (IA) in samples harvested from children and infants, with respiratory symptoms attended at University Hospital, University of Sao Paulo (USP), during the years 1995 to 2006. A total of 3,009 samples were analyzed by duplex RT-PCR and 4.38% (n = 132) were positive, being 12.1% (n = 16) Influenza B and 87.9% (n = 116) IA, where which 9% (n = 9) were H1N1 and 91% (n = 91) were H3N2 and 13.8% (n = 16) did not subtyped. The HA1 region of HA gene of 39 samples were sequenced and the sequences compared with vaccine strains and circulating strains in those years. The receptor-binding region was conserved in all samples and aminoacid changes were observed mainly in the antigenic sites and surroundings. Overall, the vaccine strains were consistent with those circulating in Sao Paulo.
Assuntos
Humanos , Criança , Genética , Alphainfluenzavirus/genética , Virologia , HemaglutininasRESUMO
Several studies conducted all over the world have reported that the influenza virus is associated with great morbidity and mortality rates. In this study, we analyzed the incidence of the influenza virus between 2000 and 2003 in Curitiba. We studied 1621 samples obtained from outpatients and hospitalized patients of both sexes and all ages. The study was conducted at the local primary care health units (outpatients) and at the tertiary care unit (hospitalized) of the General Hospital of the Federal University in the state of Paraná, Brazil. Nasopharyngeal aspirates and, eventually, bronchoalveolar lavage were assayed for the presence of viral antigens, either by indirect immunofluorescence or cell culture. Of the samples studied, 135 (8.3 percent) were positive for influenza virus, and of those, 103 (76.3 percent) were positive for type A and 32 (23.7 percent) for type B. Additionally, positive samples were analyzed by reverse transcription followed by polymerase chain reaction and subtypes H1 and H3 were identified from this group. A high incidence of positive samples was observed mainly in the months with lower temperatures. Furthermore, outpatients showed a higher incidence of influenza viruses than hospitalized patients.