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
Meningococcal disease serious, but still rare Meningococcal disease is a disease caused by a bacterium, the meningococcus. There are several types of this bacterium. In most cases, it does not make you ill.