The mean infectious doses of selected avian influenza virus (AIV) isolates, determined in domestic poultry under experimental conditions, were shown to be both host-dependent and virus strain-dependent and could be considered one measure of the infectivity and adaptation to a specific host. As such, the mean infectious dose could serve as a quantitative predictor for which strains of AIV, given...

Some assessments carried out to determine the period of time when viruses preserve their infective properties lack enough information about the environmental conditions. For instance, FITCHNER [5] affirms that during the Pennsylvania outbreak of a highly pathogenic avian influenza in 1983-1985, caused by a Н5N2 virus, the agent was detected in wet manure under field conditions after 105 days. U...

there are little information about growth properties of low pathogenic (lp) avian influenza virus (aiv) in embryonated chicken eggs (eces) at different incubation temperatures. knowledge of this information increases the quantity and quality of antigen in vaccine production process. for this purpose, 10-5 dilution of aiv (a/chicken/iran/99/h9n2) was inoculated (intra-allantoic) into 400, 11-day...

Surveillance of wild bird populations for avian influenza viruses (AIV) contributes to our understanding of AIV evolution and ecology. Both real-time reverse transcriptase-polymerase chain reaction (RRT-PCR) and virus isolation in embryonating chicken eggs (ECE) are standard methods for detecting AIV in swab samples from wild birds, but AIV detection rates are higher with RRT-PCR than isolation...

Fowl adenovirus (FAdV) is a member of the genus Aviadenovirus and causes a number of economically important poultry diseases. One of these diseases, inclusion body hepatitis (IBH), has a worldwide distribution and is characterised by acute mortality (5% - 20%) in production chickens. The disease was first described in the United States of America in 1963 and has also been reported in Canada, th...

H9N2 Avian influenza virus has repeatedly infected humans and other mammals, which highlights the need to determine the pathogenicity and the corresponding mechanism of this virus for mammals. In this study, we found two H9N2 viruses with similar genetic background but with different pathogenicity in mice. The A/duck/Nanjing/06/2003 (NJ06) virus was highly pathogenic for mice, with a 50% mouse ...

BACKGROUND Highly pathogenic avian influenza A virus has been shown to infect organs other than the lung, and this is likely to be mediated by systemic spread resulting from viremia which has been detected in blood in severe cases of infection with avian H5N1 viruses. The infectivity of virus in blood and the potential for virus transmission by transfusion has not been investigated. METHODS U...

Low pathogenic avian influenza (H9N2) is of major concern for the poultry industry especially in Iran, as the virus can spread rapidly in and between flocks, causing high mortality and severe economic losses. The aim of this study was to determine the pathogenicity of H9N2 avian influenza virus in thymus and bursa of Fabricius of commercial broiler chickens, so we studied the histologic lesions...