Dengue is the most rapidly spreading mosquito-borne viral disease in the world. In the last 50 years, incidence has increased 30-fold with increasing geographic expansion to new countries and, in the present decade, from urban to rural settings (Figure 1.1). An estimated 50 million dengue infections occur annually (Figure 1.2) and approximately 2.5 billion people live in dengue endemic countries (1). The 2002 World Health Assembly resolution WHA55.17 (2) urged greater commitment to dengue by WHO and its Member States. Of particular signif cance is the 2005 World Health Assembly resolution WHA58.3 on the revision of the International Health Regulations (IHR) (3),
which includes dengue as an example of a disease that may constitute a public health emergency of international concern with implications for health security due to disruption and rapid epidemic spread beyond national borders.