Zika, or the burden of uncertainty.

In the first phases of an infectious outbreak, health authorities have to face the challenge of communicating uncertainty. Just when the attention of the public is at the top, information about what is going on is usually still missing. This is the case of Zika crisis in Latin America, where an association with microcephaly in newborns and neurological complications have been described, but not yet confirmed. Despite this, and even if the risk would be mainly limited to pregnant women, Zika threat is perceived by the general public as greater than others, such as those from dengue or flu. Some peculiarities of this outbreak explain such a gap between real and perceived risk. Nevertheless, in such a situation, WHO and other health authorities have the duty to act out of an abundance of caution, aware of the lose-lose game they are going through: if they raise alarm, and this subsided, they could be accused to fuel people's fears because of economic interests, as it happened in 2009 A(H1N1) pandemic; if they underestimate the threat, they could find themselves in front of a global tragedy.