A new study suggests that dengue virus infects an estimated 390 million people worldwide each year, a number 3 times higher than an estimate cited by the World Health Organization.
Most people infected with 1 of the 4 closely related dengue viruses experience no symptoms. Still, the new research suggests about 96 million individuals will have clinical effects ranging from mild fever to potentially fatal dengue shock syndrome.
The new estimate (Bhatt S et al. Nature. doi: 10.1038/nature12060 [published online April 7, 2013]) is the result of modeling that inferred the public health burden of the disease in 2010 by mapping the global distribution of dengue risk and pairing it with dengue cohort studies and population distributions. The international team of researchers predicted that dengue, which is transmitted to humans by Aedes mosquitoes, is ubiquitous throughout the tropics, with local variations in risk influenced by rainfall, temperature, and degree of urbanization. The researchers also stratified their estimates of infection by country, allowing for comparison with national dengue reporting.