Dengue prevention and control

Overview

Dengue is the most common and wide-spread arthropod-borne viral infection in the world. There are 4 distinct virus serotypes, each capable of producing a wide spectrum of signs and symptoms that characterize dengue fever, ranging from subclinical infection, to a debilitating but self-limiting illness with symptoms resembling influenza, to severe disease known as dengue haemorrhagic fever. Without proper hospitalcare, the latter can lead to clinical shock and death in less than 24 hours.

The geographical spread, incidence and severity of dengue fever and dengue haemorrhagic fever are increasing in the Americas, the Eastern Mediterranean, South-East Asia and the Western Pacific. Before 1970, only 9 countries had experienced dengue haemorrhagic fever. Since then, the number has increased more than fourfold and continues to rise. Some 2.5-3 billion people live in areas where dengue viruses can be transmitted. A pandemic in 1998, in which 1.2 million cases of dengue fever and dengue haemorrhagic fever were reported from 56 countries, was unprecedented. Preliminary data for 2001 indicate a situation of comparable magnitude. However, only a small proportion of cases are reported to WHO; it is estimated that each year 50 million infections occur, with 500 000 cases of dengue haemorrhagic fever and at least 12 000 deaths, mainly among children, although fatalities could be twice as high.