World Cup 2014 in Brazil: Study Shows Areas with High Dengue Risk

A new study has found "high risk sites" for dengue during the soccer World Cup in Brazil. The research could serve as an early warning call to the authorities managing the game.

Researchers have found three regions - Natal, Fortaleza and Recife - where there high risk of dengue outbreak. However, the disease risk is still considered to be low in all 12 cities that are hosting the event.

Dengue is caused by any one of the four viruses that are transmitted by the infected female Aedes mosquito. According to the WHO, the disease has dramatically increased in the last few decades. Currently, about half of the world population is at risk of dengue fever. Brazil has had 7 million cases reported between 2000 and 2013, making it the worst-affected countries in the world.

The soccer World Cup is scheduled for June 12 to July 13. A million fans are expected to travel to the 12 venues during the event, BBC reported.

The U.S. and Canada have issued travel health notice about the Fédération Internationale de Football Association's World Cup. The Centers for Disease Control and Prevention (CDC) has asked travelers to avoid mosquitoes and use insect repellants.

"Recent concerns about dengue fever in Brazil during the World Cup have made dramatic headlines, but these estimates have been based solely on averages of past dengue cases," said Dr Rachel Lowe from the Catalan Institute of Climate Sciences in Barcelona, Spain.

"The possibility of a large dengue outbreak during the World Cup, capable of infecting visitors and spreading dengue back to their country of origin, depends on a combination of many factors including large number of mosquitoes, a susceptible population and a high rate of mosquito-human contact," explained Lowe, who is the lead author of the study, in a news release.

The warning covers 553 micro-regions in Brazil. Researchers looked at the climate data between 1981 and 2013. They also assessed information about population density, BBC reported.

Rain and temperature play an important role in dengue outbreak. Periods of heavy rain, followed by warm weather, leads to an increase in disease-carrying mosquitoes.

Researchers found that major regions hosting the World Cup have low risk of the disease outbreak. However, Natal, Fortaleza and Recife have high risk - while Rio de Janeiro, Belo Horizonte, Salvador and Manau had moderate risk of dengue.

The research is published in the journal The Lancet Infectious Diseases. It was funded by European Commission's Seventh Framework Research Programme projects DENFREE, EUPORIAS, and SPECS; Conselho Nacional de Desenvolvimento Científico e Tecnológico and Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro.