The Zika virus isn't new, it was first observed in Africa in 1947, the main physical symptom was a 'rash'.
The virus consists of simple RNA, and is easily subject to mutation and change.
There is evidence that viri may mutate when affected by external conditions such as chemical exposure, climate change, or any number of variables
and like all living things, it adapts and changes in order to survive.
The Zika may have just mutated and changed, and as it biologically changed and adapted, it may have developed different physical response in the host.
One of those changes may be microcephally , physical and social retarded development , neurological responses, and possibly organic an chemical changes in the host.
There is still much to learn about Zika - this latest study was just relased two days ago , which indicated that there may be organic and chemical changes in the host adult brain.
OK, so much for my planned vacation in south Florida. Too many Democrats down there, anyway.