Resumo
Although the natural reservoirs of the avian influenza (AI) virus have been extensively studied in many countries, there is a clear lack of information on this subject in South America, particularly in Brazil. The objective of this study was to conduct a serological survey for H5, H7 and H9 antibodies to AI-subtype viruses in wild birds in the state of São Paulo , Brazil. Serum samples were tested using the hemagglutination-inhibition assay. Out of the 31 wild birds sampled between January and December of 2006, seven (22.58%), were seropositive for H5, H7 and H9; four (12.90%) were seropositive for H5 and H7; 13 (41.94%), were seropositive only for H7; three (9.7%), were seropositive only for H9; and four (12.90%) were negative for all three hemagglutinin subtypes. These results indicate that AI viruses belonging to H5, H7 and H9 subtypes circulate among wild birds in the state of São Paulo in the form of either concurrent or consecutive infections. This study contributes to the knowledge of AI epidemiology in Brazil, and stresses the need of further detailed and long-term epidemiological and ecological investigation to determine the current status of this virus.
Resumo
Brazil is one of the world's largest countries with a rich diversity of wildlife, including resident and migratory wild birds, which may be natural reservoirs of the Newcastle disease virus (NDV). Because Brazil is a major global exporter of chicken meat, the emergence of such a disease may have a huge negative impact not only on the economy due to trade restrictions and embargoes, but also on the quality of life of the population. Samples were collected from 1,022 asymptomatic domestic and wild birds from the Brazilian coast and the Amazon region using tracheal/cloacal swabs and tested by RT-qPCR. The results showed 7 (0.7%) birds were positive for NDV. The positive samples were then isolated in embryonated chicken eggs and their matrix protein genes were partially sequenced, revealing a low-pathogenicity NDV. This study confirms the maintenance of the velogenic-NDV free status of Brazil.
Resumo
ABSTRACT Caprine arthritis encephalitis is a multisystemic infectious disease caused by a lentivirus and may affect animals of any age or sex. The major symptoms are leukoencephalomyelitis, chronic interstitial pneumonia, arthritis and hardening interstitial mastitis. It has been reported that the testicles of infected animals present infected semen and a gradual inflammatory process. For the detection of the agent in semen samples, PCR and nested PCR techniques are characterized as methods with high specificity and sensibility that provide fast results. The objective of this study was to detect the presence of pro-lentiviral DNA in the semen of caprine males in São Paulo State, Brazil, by the PCR and nested PCR molecular techniques. Five (29.4%) of the 17 samples presented positivity for the detection of the virus, proving the presence of viral particles in the semen of male goats seropositive for caprine arthritis encephalitis in this study.
RESUMO A Artrite Encefalite Caprina é uma enfermidade de caráter multissistêmico afetando animais de qualquer idade e sexo; causado por um Lentivirus caprino pertencente ao grupo de Lentivirus de Pequenos Ruminantes. Os sintomas conhecidos são leucoencefalomielite, pneumonia intersticial crônica, artrite e mastite intersticial endurativa. Foi descrito que machos soropositivos apresentavam sêmen infectado pelo Lentivirus e processo inflamatório gradual do testículo. A detecção em amostras de sêmen pelas técnicas de PCR e nested-PCR são caracterizadas como métodos de altas especificidade e sensibilidade provendo resultados rápidos. O objetivo do estudo foi detectar, por meio da técnica molecular de PCR e nested-PCR, a presença de DNA pró-viral do Lentivirus caprino em amostras de sêmen de reprodutores criados no Estado de São Paulo. Das 17 amostras, cinco (29,4%) apresentaram a detecção do vírus provando que há a presença de partículas virais no sêmen dos caprinos reprodutores soropositivos a Atrite Encefalite Caprina estudados.