Challenges in dengue surveillance and control

Globally, the challenge posed by dengue has escalated at an astonishing rate in the last three decades, with no sign of abating. It is estimated that dengue affects at least 50 million – 100 million people every year. With more than 120 dengue-endemic countries, 3.6 billion people are at risk of infection. More than 70% of those at risk reside in the Asia Pacific region, making this region an epicentre of dengue activity.In addition to making a comeback in places such as the Americas and Singapore, where dengue was previously successfully controlled for decades, the virus has also breached the subtropical-temperate barrier as it claims new territories. In the last decade, dengue transmission has extended its reach into places as far north as Nepal, Ningbo in China and France, and as far south as Bueno Aires in Argentina. The Pacific islands, with much lower population densities, have also not been spared, with increasing dengue outbreaks since the 1970s.The direct economic and social impact of dengue on dengue-endemic regions is high,9–12 and the burden in other aspects such as the security of blood supplies is increasingly being recognized. Dengue’s threat to travellers has also been systematically demonstrated by a 2008 study on 6957 travellers who returned ill and sought treatment from EuroTravNet centres. Of those travellers, 1.9% were diagnosed with dengue, and one of the three deaths reported was due to dengue shock syndrome