Public health officials say thousands of football fans may be at risk from the disease, which can cause excruciating joint pain and haemorrhagic fever British football fans have been warned that they run the risk of contracting dengue fever, if they do not take adequate protection.
With around three million tickets sold for the World Cup, around half a million football fans are expected to go to Brazil in June and July this year. Many of the English contingent may be expecting sunburn or heatstroke to be their biggest health concerns.
But Simon Hay, professor of Epidemiology at Oxford University, says World Cup fans may be at risk from a far more serious problem.
Dengue fever is endemic in parts of Brazil, particularly in the northeast. There were 1.4 million cases nationwide last year.
Scientists working with Prof Hay have identified nine of Brazil’s stadiums as being in dengue-plagued areas.
“Dengue fever could be a significant problem in some of the tournament locations, and preventive measures are needed,” Prof Hay writes in the journal Nature.
“Fifa, the Brazilian authorities and the World Cup sponsors must use their influence and experience to communicate the risk.”
The season for dengue fever usually ends in May, a month before the World Cup is due to begin.
But the northeast of Brazil is experiencing a heatwave, and public health officials warn that the mosquito breeding season may extend through the World Cup.
The north-eastern cities of Natal, Fortaleza, Recife and Salvador will host 21 games between them, including Germany vs Portugal, Spain vs the Netherlands and potentially, several England games.
England’s first game against Italy will be held in the humid setting of Manaus, in the Amazon rainforest.
If England finish top of their group, they will play the runners-up from Group C in Recife’s Arena Pernambuco on June 29.
Should they win that game, their quarter-final will be held in Salvador’s Arena Fonte Nova six days later.
If they finish second, their quarter-final will be held in the Estadio Castelao in Fortaleza.
Climate researchers from the University of Reading say there is a 60 per cent chance of an El Nino event during the World Cup, which could cause heatwaves and drought in Brazil.
El Nino is characterised by higher sea temperatures in the Pacific Ocean.
It usually causes high amounts of rain, leading to floods on the west coast of North America.
But in South America, it can cause drier and hotter weather and create the ideal breeding conditions for mosquitoes.
Dengue fever is a viral infection that usually produces a severe fever and high temperature, among other symptoms that may require hospitalisation.
The disease has a simple stage and a severe stage that affects around five per cent of sufferers.
It can cause seizures and excruciating joint pain, explaining why dengue is also known as “break bone fever”.
The virus has five separate subtypes, with subsequent infection by another type more likely to lead to severe symptoms, such as the life-threatening dengue haemorrhagic fever.
It is transmitted by female Aedes aegypti mosquitoes, which bite during the day and lay their eggs on stagnant water.
There is no cure or vaccine, so public health bodies in Brazil have tried to reduce the threat of Dengue fever using insecticides and larvicides, and by targeting the areas of water on which mosquitoes breed.
But there may be a novel solution on hand in time for the World Cup.
British biotec company Oxitec has created a mosquito with a modified gene that can only be kept alive with the antibiotic tetracycline. The modified males are released to mate with the wild female population. Their offspring is unable to survive without antibiotics.
Brazil has, for the past two years, conducted a trial of the genetically modified mosquitoes in Bahia state.
Brazilian firm Moscamed released the world’s largest ever swarm of GM mosquitoes in Jacobina, a town in Bahia, last month.
“We need to provide alternatives because the system we have now in Brazil doesn’t work,” said Aldo Malavasi, the president of Moscamed.
“We have thousands and thousands of cases of dengue and that costs a lot for the country. People are unable to work.”
The company has reported a 90 per cent drop in wild Aedes aegypti mosquitoes in the town so far.