With this World Health Day, WHO is drawing attention to a group of diseases that are spread by insects and other vectors, the heavy health and economic burdens they impose, and what needs to be done to reduce these burdens. Many of these diseases have been historically confined to distinct geographical areas, but this situation has become more fluid due to a host of ills, including climate change, intensive farming, dams, irrigation, deforestation, population movements, rapid unplanned urbanization, and phenomenal increases in international travel and trade. The control of vector-borne diseases can make a major contribution to poverty reduction, as it precisely targets the poor