The first case of Zika virus in humans was documented in 1960. For decades, Zika remained in obscurity until an outbreak on the island of Yap in 2007. Another epidemic occurred on French Polynesia in 2013, that reached Brazil in 2014. In 2016 over 20 countries in the Americas have Zika transmission. What changed?
It is possible that the virus has mutated to a more virulent form.
The virus could have mutated to a form that has greater transmission.
The human population in the…
Source: Living With Insects Blog