• Tropical & sub-tropical regions.

• Urban & peri-urban areas.

• 4 factors for highly favourable epidemiological conditions for viral transmission by Aedes aegypti:

- population growth (doubled in last 27   years).

- rural-urban migration.

- inadequacy of basic urban infrastructure.

- exponential growth of consumerism.

• DHF first recognised in1950s.

• Leading cause of childhood mortality in several Asian countries.

• Endemic in >100 countries in Africa, the Americas, the Eastern Mediterranean, South-East Asia & the Western Pacific. Latter two are most seriously affected.

• 2.5 billion people – 2/5 of the world population – are at risk

• 50 million cases of dengue infection worldwide every year.

• 616.000 cases in the Americas in 1998 – of whom 11.000 were DHF.

• 475.000 cases in Brazil in 1998.

• 500.000 cases of DHF/DSS require hospitalisation each year – of whom 24.000 dies (5%) with large proportion of children.

• Depending on proper clinical management, DHF case fatality rate can be >20% to <1%.

• 3 medium-term priorities (4-6 years) as per WHO consultation of global strategy review in October 1999:

• strengthening surveillance for planning & response (DengueNet, a global surveillance system for dengue fever on the internet).

• reducing disease burden (training & adoption of WHO standard clinical management guidelines for DHF, improving emergency preparedness & response).

• Changing behaviours (package of tools, individual/household/community/ institutional/political levels, intra & inter-sectoral partnerships).