New research out of the University of Wisconsin-Madison School of Veterinary Medicine reveals that a novel compound proves highly effective against the pathogenic H5N1 avian influenza virus. The study, led by virologist Yoshihiro Kawaoka, professor of pathobiological sciences, appeared in the Public Library of Science journal PLoS Pathogens on Feb. 26. It suggests that the compound CS-8958 is a promising alternative antiviral for prevention and treatment of bird flu. Antiviral drugs are a key countermeasure against human influenza viruses, according to the university. This includes the pathogenic H5N1 avian influenza virus, which causes bird flu. The emerging strains resistant to existing drugs, particularly oseltamivir (Tamiflu), make the development of alternate antivirals a public health issue, Kawaoka said. He and researchers from Japan, Vietnam and Indonesia tested a neuraminidase inhibitor R-125489 and its prodrug CS-8958, which had previously shown potent activity against seasonal influenza viruses in laboratory animals. Working with mice, the researchers learned that a single intranasal dose of CS-8958 given two hours after infection with H5N1 influenza virus resulted in a higher survival rate and lower virus levels than a standard five-day course of oseltamivir. CS-8958 was also effective against highly pathogenic and oseltamivir-resistant strains of H5N1 virus, the university said. In addition, CS-8958 protected mice against lethal H5N1 infection when given seven days before infection with the virus. This compound requires a single administration for treatment and prophylaxis, Kawaoka said. Although further studies are needed to confirm the applicability of the findings to humans, CS-8958 is highly effective for the treatment and prophylaxis of infection with H5N1 influenza viruses, including oseltamivir-resistant mutants, the authors said. <HOME>
