It's also likely been in the two carrier species of mosquito for longer than human cases of Zika were recorded, which exist as far north as US and Europe and as far south as Australia. Of course it's most likely the Americas variants of these mosquitoes likely got their carrier status due to drinking infected humans, I don't recall it actually originating in the Apes of the Americas so the Brazillian outbreak is unlikely to have begun from the mosquito but still possible. Of course when the disease can also be given via a blood transfusion on top of two very easily transmissible methods if caution is not taken, making tracking a patient zero even more murky. Though as the prolific spread did not occur during 2013's initial hop nor 2014's event I find it unlikely the World Cup is directly responsible for the outbreak in April 2015. Though Brazil's unstable nature since then (and due to it's cost among other things) has certainly made it possible for a disease to spread due to the disruptions of public services that may have gotten to it under control before it became a problem. But that's just a hypothetical as Zika even half a century later didn't come up much till the outbreak so even with Brazil at it's pre unrest level of services might still have overlooked it and misidentified symptoms for other diseases.
But that's neither here nor there, the Americas has Zika now, so how best to deal with it till a vaccine is developed? Yes postponing the Olympics is likely a 100% successful method of preventing region hoping to continue. Though its unlikely to stop the spread north and further south due to the wide range the mosquitoes cover, as it wouldn't take a few infected people to cross into the US to help give their region's mosquitoes (if they don't have it already) the disease when they feed on that person. But it would likely prevent alot of European risk, till the US gets cases as there is alot of European travel to the US for business and vice versa. Assuming of course no vaccine can be discovered and the infection rate continues increasing it's pace. Most nations above the snow line would only need to screen blood and avoid unprotected sex with foreigners (unlikely) as they lack the mosquitoes that become the major carrier for spreading beyond person to person contact.
Nope I haven't thought much about this, but then I don't think much about the next big epidemic sweeping the news.