The global burden of dengue infection is more than triple current estimates from the World Health Organization, according to a
multinational1 study published today in the journal Nature. The research has created the first
detailed2 and up-to-date map of dengue distribution worldwide, enabling researchers to estimate the total numbers of people
affected3 by the virus globally, regionally and nationally. The findings will help to guide efforts in
vaccine4, drug and
vector control(传病媒介控制) strategies.
The study was led by Professor Simon Hay, a Wellcome Trust Senior Research Fellow at the University of
Oxford5, as part of the International Research Consortium on Dengue Risk
Assessment6, Management and Surveillance.
Dengue, also known as 'breakbone fever', is a viral infection that is transmitted between humans by mosquitoes. In some people, it causes life-threatening illness.
There are currently no
licensed7 vaccines8 or specific treatments for dengue, and substantial efforts to control the mosquitoes that transmit the disease have not stopped its rapid
emergence9 and global spread. Until now, little was known about the current distribution of the risk of dengue virus infection and its public health burden around the world.
Dr Samir Bhatt, who led the modelling for the study, says: "Our aim was to take all of the evidence that is currently available on the distribution of dengue worldwide and combine it with the latest in mapping and mathematical modelling to produce the most refined risk maps and burden estimates. We then hope to use this knowledge to help predict the future burden of the disease."
The findings reveal that dengue is ubiquitous throughout the tropics, with local
spatial10 variations in risk influenced strongly by rainfall, temperature and urbanisation. The team estimate that there are 390 million dengue infections across the globe each year, of which 96 million reach any level of clinical or subclinical severity. This is more than triple the WHO's most recent estimates of 50-100 million infections per year.
Professor Simon Hay explains: "We found that climate and population spread were important factors for predicting the current risk of dengue around the world. With globalisation and the constant march of urbanisation, we anticipate that there could be dramatic shifts in the distribution of the disease in the future: the virus may be introduced to areas that
previously11 were not at risk, and those that are currently affected may experience increases in the number of infections.
"We hope that the research will
initiate12 a wider discussion about the significant global impact of this disease."