What is the experience from previous mass gathering events? Lessons for Zika virus and the Olympics 2016

SummaryAll previous experiences from different mass gathering show that vaccine preventable diseases is the most important infections like influenza, hepatitis A, polio and meningitis. Three mass gathering held in Africa during the Ebola outbreak accepted participants from West Africa and was able to handle the theoretical risk without any incident. Therefore we believe that the Olympic games in Rio de Janeiro should not be cancelled. The number of visitors to the games is a tiny fraction (1%) of other visitors to Zika endemic countries and it will have no measurable effect on the risk of spreading Zika virus, if the games was cancelled.