Dengue is endemic in Asia, Southeast Asia, several
southern and central Pacific countries and the
Americas, with several outbreaks in India.Over 2.5
billion people (more than 40% of the world’s population)
are now at risk from dengue. WHO currently
estimates that 50–100 million dengue infections
may be occurring worldwide each year. An estimated
500 000 people with severe dengue require hospitalisation
annually, a large proportion of whom are
children and about 2.5% of those affected die.
Recent studies indicate higher incidence in
infancy,although the severity of illness among
adults is increasing and has higher case-fatality
rates (CFR); this age shift is obvious in some
endemic Southeast Asian countries.There are
racial differences in mortality and morbidity with
lower infection rates and case fatality in black
than in white patients.It has also been reported
that the disease is more severe in females than
males, although the incidence is higher in males.
This has been attributed to more competent
immune responses in females, resulting in greater
production of cytokines and a tendency of capillary
beds in females to increased permeability.
The overall CFR in the South-East Asia Region is
now less than 1%.