The WHO took a pivotal role in the investigation of the outbreak, with the development of a case definition for severe acute respiratory syndrome (SARS) (fig. 1⇓) 1. Global Outbreak Alert and Response teams assisted in outbreak management and the collection of epidemiological and clinical data to improve the understanding of the condition. A global network of 11 leading laboratories in 10 countries was established to collaborate in the search for the causative organism and daily updates were provided on the WHO website. Electronic grand rounds were commenced to enable sharing of information and experience of the condition.