Grey heron infected with West Nile virus A grey heron in the Noord-Holland-Noord region has tested positive for the West Nile virus. The virus is rare in the Netherlands. Bas van de Meulengraaf
New RIVM-method used to detect influenza A (H7H9) population immunity The level of immunity to the recently circulating H7N9 influenza virus in an urban and rural population in Vietnam is very low, according to the first population level study to examine human immuni