[In Depth] Don't blame sports for Zika's spread
Since the Zika virus began racing through the Americas, scientists have been trying to figure out when and where it entered Brazil, where it was first detected in March 2015. Speculation has focused on the influx of fans for the World Cup in June and July 2014, or for a championship canoe race in September 2014. But a new genome analysis suggests the virus had likely been spreading there long before either event, having arrived sometime between May and December 2013. It could have arrived during the Confederations Cup soccer tournament in late June 2013, the authors say. That event brought the Tahitian national team to a stadium in Recife, near the epicenter of the Brazilian epidemic. But that was several months before cases of Zika were reported in Tahiti, and the authors think it's more fruitful to look at broader travel patterns rather than discrete events. They point out...