Mutations acquired trans-Pacific may be key to changes in Zika severity

The Zika virus remains a mystery. Isolated from macaque monkeys in the Ziika Forest in Uganda in 1947, the virus was shown to infect humans not long after, but it was identified as a benign disease, with mild symptoms. For this reason, it was not heavily studied until almost 70 years later when it appeared to be associated with an unusual cluster of cases of microcephalic birth defects and Guillain-Barré Syndrome (GBS) paralysis in Brazil in 2015 and 2016.

If the at-least-70-year-old virus is responsible for the recently reported neurological diseases, why were the first serious effects not noticed until recently? And, why were these effects first in Brazil, very distant from its continent of apparent origin, Africa? The mysterious history of the virus matters because its details might tell us the backstory of how it came to be what it is where it is and from that, why it is doing so much damage.

Mutations acquired trans-Pacific may be key to changes in Zika severity