Dengue fever hits 390m every year
10 July 2013 09:30
Dengue fever is a mosquito-borne viral disease, colloquially known as "breakbone fever" because symptoms can include agonising joint pain
Nearly 400 million people are infected with dengue fever each year, making it the world's fastest-growing tropical disease, new research has revealed.
There are 96 million severe cases and approximately 300 million mild or asymptomatic episodes every 12 months, according to a study published in the journal Nature.
That is more than triple the World Health Organization's current forecast of 50-100 million a year, researchers from the University of Oxford and the Wellcome Trust said.
Dengue fever is a mosquito-borne viral disease, colloquially known as "breakbone fever" because symptoms can include agonising joint pain.
It is not usually fatal, but lands many victims in hospital and can lead to a number of other more life-threatening conditions such as dengue hemorrhagic fever and dengue shock syndrome, the latter of which causes dangerously low blood pressure.
At present there is no approved vaccine or specific drug to treat dengue, so it is vital travellers take out
medical travel insurance if they intend to visit an area where the disease is prevalent. People with existing medical conditions should also make sure they arrange
pre-existing medical travel insurance before jetting off.
The high number of relatively mild dengue cases offers little cause for comfort, since it suggests the "reservoir" of disease is far larger than expected, scientists said.
Moreover, being bitten by a dengue-infected mosquito does not create immunity to further infection - on the contrary, it increases the chances of a serious episode if bitten again in the future.
Approximately 70% of the world's serious dengue cases were in Asia, with India alone accounting for more than a third (34%) of the total, researchers estimated.
The Americas - in particular Brazil and Mexico - made up 14% of the total serious infections, while a similar proportion occurred in Africa.
However, climate change is making more parts of the planet hospitable for the dengue-spreading Aedes aegypti mosquito.
Europe experienced its first major outbreak of dengue fever since the 1920s last year, when around 2,000 people were infected in the Portuguese archipelago of Madeira.
Jeremy Farrar, director of Oxford University's tropical disease research unit in Vietnam, said more such outbreaks were likely as the mosquito is already present in southern Europe and the number of people travelling to and from dengue-infected areas is on the rise.