There is a possibility that Brazil 2014 will be remembered as the dengue fever World Cup.
Dengue, an infection spread by mosquitoes, "could be a significant problem" in some of the host cities, a leading British expert has warned, amid growing evidence that the disease is "on the march" around the world.
Brazil saw well over a million cases last year and the global tally now totals, by some estimates, around 400 million annually, the Independent reported.
The disease causes severe headaches and aching in the bones and joints, which can get so bad it has earned the sobriquet "breakbone fever". Around a quarter of victims become very unwell and in a small proportion of cases it can be fatal.
Although the World Cup is being held at a time of year when the dengue risk is low for most parts of Brazil, for three host cities in the north east - Fortaleza, Salvador and Natal - it will be close to its peak, Professor Simon Hay, an epidemiologist at the University of Oxford, who raised the alarm in the journal Nature at the end of last year, said.