The epidemic strain of Zika was in French Polynesia in 2014.
Sports people (soccer or canoe) flew their Zika-infected blood into Brazil.
Mosquitos in Brazil bit them and became infected with Zika.
They have bitten and infected over a million people in the Western Hemisphere.
Thousands of Zika birth defects have resulted.
Over 500,000 people will fly out of Brazil after the Olympics in August.
Thousands will carry Zika-blood around the globe and be bitten by compatable mosquitos.
Virus category listing has
Based mainly on chart showing 5X - 10X reduction in Dengue during that time in previous years