WHO Report on Global Surveillance of Epidemic-prone Infectious Diseases - Dengue and dengue haemorrhagic fever
- The Americas, South-East Asia and the Western Pacific are most seriously affected. Some 2.5 billion people - two-fifths of the world's population - are now at risk for acquiring dengue.
- A rapid rise in unplanned urbanization is bringing ever greater numbers of people into contact with Ae. aegypti mosquitos by increasing favourable breeding sites for the mosquitos. These include peri-urban and slum areas where household water storage is common and where solid waste disposal services are inadequate.
- Infection with one serotype predisposes individuals to DHF when subsequently infected with a different serotype. DHF now occurs regularly in countries that previously reported only DF because of the introduction and circulation of multiple dengue virus serotypes.
- Without proper treatment, DHF case fatality rates can exceed 20%. With supportive therapy, it can be reduced to less than 1%.
Map 6.1 The general distribution of dengue fever and/or dengue haemorrhagic fever, 1975-1996