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Variable endemicity
for DF/DHF in countries of SEA Region
Although Dengue/Dengue Haemorrhagic
Fever is endemic in most countries of the region, all four serotypes have
been detected in all the countries . The
transmission potential, however , is different both
at the macro- and micro levels.
The current situation of DF/DHF in countries of
the South East Asia Region can be stratified
as follows:
Category A (Indonesia, Thailand,
Sri Lanka
and Timor- Leste)
 Major public health problem
Leading cause of hospitalization and death
among children
Cyclical epidemics in urban centers
Spreading to rural areas
Multiple virus serotypes circulating
Category B (Bangladesh, India,
Maldives)
Cyclical epidemics are becoming more frequent
Multiple virus serotypes circulating
Expanding geographically within countries
Category C ( Bhutan and Nepal )
Endemicity uncertain
Bhutan: First outbreak reported
in 2004
Nepal: Reported dengue cases for
the first time in November 2006.
Category D ( DPR Korea
)
No evidence of endemicity.
While the ecological and climatic factors influence the
seasonal prevalence of the species, factors related to human ecology
determine the extent and intensity of breeding. On the basis of climatic
factors, the countries oft the Region can be divided into four distinct
climatic zones with different DF/DHF transmission potential. These are as
follows:
Tropical Monsoon and Equatorial Climatic Zone
Deciduous Dry and wet Climatic Zone
Sub-Himalayan foothill Region
Temterate Climate Region
Tropical Monsoon
and Equatorial Climatic Zone
This zone includes four countries, viz. Indonesia, Myanmar,
Thailand
and Timor-Leste. The annualrainfall
in this zone is >150 cm. Aedes aegypti is widespread in both urban and rural areas.
Transmission is extended and DHF epidemics occur in 3-5 years cycles,
associated with high morbidity in children.
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