The RNAs of several classes of avian and murine RNA tumor viruses were compared. The 60-70s RNA complex of cloned nondefective avian sarcomaviruses contains only 30-40s RNA species of class a, which are larger than the 30-40s RNA species of class b found in avian transformation-defective or leukosis viruses. The RNA of a recombinant avian sarcoma virus, carrying a host range marker of a leukosi...

Avian influenza viruses have adapted to human hosts, causing pandemics in humans. The key host-specific amino acid mutations required for an avian influenza virus to function in humans are unknown. Through multiple-sequence alignment and statistical testing of each aligned amino acid, we identified markers that discriminate human influenza viruses from avian influenza viruses. We applied strict...

human infection with avian influenza a h7n9 virus has emerged in china with high morbidity rates. patients usually present with severe and rapidly progressive pneumonia. therefore, radiological findings are important to diagnose and evaluate disease severity. the clinical characteristics of three new cases of h7n9 virus infection were analyzed, especially the radiological findings, and previous...

An apparent DNA-binding protein is described that is specific for cells transformed by avian acute leukemia viruses. This protein cannot be demonstrated in cells transformed by any of the avian sarcoma viruses or in cells infected with nontransforming avian retroviruses. The protein also is not detectable in noninfected quail or chicken embryo primary cultures or in noninfected chicken hematopo...

Inoculation of avian oncoviruses into 1- to 2-month old chickens led to a rapid production of antiviral humoral antibodies. Under these conditions it was found that avian leukosis viruses are sequestered in macrophages of peripheral blood, in which they can persist for a long period of time (up to about 3 years). In contrast, avian sarcoma viruses were never found in macrophages from chickens d...

BACKGROUND The influenza viruses circulating in animals sporadically transmit to humans and pose pandemic threats. Animal models to evaluate the potential public health risk potential of these viruses are needed. METHODOLOGY/PRINCIPAL FINDINGS We investigated the guinea pig as a mammalian model for the study of the replication and transmission characteristics of selected swine H1N1, H1N2, H3N...

We studied receptor-binding properties of influenza virus isolates from birds and mammals using polymeric conjugates of sialooligosaccharides terminated with common Neu5Ac alpha2-3Gal beta fragment but differing by the structure of the inner part of carbohydrate chain. Viruses isolated from distinct avian species differed by their recognition of the inner part of oligosaccharide receptor. Duck ...

Highly pathogenic avian influenza virus A/H5N1 has been reported in 11 African countries. Migratory waterbirds have the potential of introducing A/H5N1 into east Africa through the Rift Valley of Kenya. We present the results of a wild bird surveillance system for A/H5N1 and other avian influenza viruses based on avian fecal sampling in Kenya. We collected 2630 fecal samples in 2008. Viral RNA ...

Influenza A viruses (IAVs) are zoonotic agents, capable of crossing the species barriers. Nowadays, they still constitute a great challenge worldwide. The natural reservoir of all influenza A viruses are wild aquatic birds, despite the fact they have been isolated from a number of avian and mammalian species, including humans. Even when influenza A viruses are able to get into another than wate...

Avian influenza A H5N1 viruses continue to spread globally among birds, resulting in occasional transmission of virus from infected poultry to humans. Probable human-to-human transmission has been documented rarely, but H5N1 viruses have not yet acquired the ability to transmit efficiently among humans, an essential property of a pandemic virus. The pandemics of 1957 and 1968 were caused by avi...