The latest outbreak began in early 2015 in Brazil, although the first cases seemed to have already appeared in 2014. One theory is that the virus arrived during the 2014 Football World Cup. Zika virus infections were reported on all continents, however, the Americas were the most at-risk-part of the world. In 2017, it was estimated that over 120 million people in Brazil were at risk of Zika virus infections, compared to 32 million people in Mexico and 29.5 million in Columbia.
Brazil was by far the country most affected by this epidemic, reporting the most cases of people infected with the Zika virus worldwide. In 2016, the state of Rio de Janeiro alone reported over 71,000 probable Zika virus infections, however this number dropped to only 2,210 cases in 2017. As of December 2017, some 2,952 confirmed cases of Zika-related microcephaly in newborns were reported in Brazil.
In the U.S., there were 61 Zika virus infections reported in 2015, then over 5,000 reported in 2016, and only 407 in 2017. Florida was the state with the highest number of reported Zika virus cases in 2016, with 1,115. However, this number also dropped to just 104 in 2017. As of June 2017, over half of U.S. adults admitted that they knew nothing or only a little about the Zika virus, despite widespread news coverage of the epidemic.