Inerim Guidance. These guidelines have been developed in recognition that infection with Zika virus may present a risk to blood safety, and in consideration of the declaration on 1 February 2016 by the WHO Director-General of a Public Health Emergency of International Concern with regard to clusters of microcephaly and other neurological disorders, potentially associated with Zika virus. Currently there is limited knowledge of Zika virus biology and lack of definitive evidence of a link between infection and potential complications