18.03.2011

Although oral exposure to H5N1 highly pathogenic avian influenza viruses is a risk factor for infection in humans, it is unclear how oral exposure to these virus results in lethal respiratory infections. To address this issue, a researchers group from Japan inoculated ferrets and hamsters with two highly pathogenic H5N1 strains. These viruses, inoculated directly into the stomach, were isolated from the large intestine and the mesenteric lymph nodes within one day of inoculation, and subsequently spread to multiple tissues, including lung, liver, and brain. Comparable results were obtained with the hamster model. The researchers conclude that, in mammals, ingested H5N1 influenza viruses can disseminate to non-digestive organs, possibly through the lymphatic system of the gastrointestinal tract (Journal of Virology).