For a pathogen that was virtually unknown a year ago, Zika virus' spread into the Americas (and the news cycle) has shown an epidemic in action. The arrival of the flavivirus to Latin America and the Caribbean during the last year has coincided with a notable rise in cases of microcephaly, a neurological condition which leads to developmental delays and in severe cases, death. CNN reports that since last year, Brazil has had 4,180 cases of microcephaly compared just 146 cases in 2014.

The virus had been found in a few babies born to infected mothers (80% of individuals are asymptomatically infected), but the causal relationship between Zika infection during pregnancy and microcephaly remains unproven. Despite this, many governments have recently issued travel advisories for pregnant women to avoid vacationing in endemic areas (which comprises now of at least 24 countries). Likewise, some countries that have detected Zika are recommending that women delay their pregnancies until more is known regarding the disease.