Zika virus: a particular risk for pregnant women An infectious diseases experts comments on the Zika public health emergency as a case of sexual transmission on US soil of the tropical, mosquito-borne virus has stirred unease among ordinary people and experts alike. The lone case has highlighted how little we know about the virus circulating in Latin America and the Caribbean, where it is suspected of causing a surge in brain-damaged babies. IMAGES AND SOUNDBITES from expert Professor Jean-François Delfraissy