Dengue in the tsunami stricken countries in Asia
The viruses that cause dengue fever and dengue haemorrhagic fever are transmitted by the mosquito Aedes aegypti, and in Asia to a lesser extent by Ae. albopictus. Aedes aegypti breeds mainly in water collections in artificial containers in the environment of human settlements, but not in groundwater pools and puddles, nor in swamps or other large natural bodies of water. Effective prevention and control of epidemic dengue requires control of Ae. aegypti.
There is no vaccine to prevent dengue infection, nor are there drugs to combat the disease in infected persons.
Aedes aegypti in the tsunami stricken areas
All countries affected by the Tsunami are endemic to dengue.
In temporary shelters where drinking water comes from outside sources or from rainwater harvesting, there will be a tendency to store drinking water in containers that may become breeding places of Ae. aegypti (and to a lesser extent of Ae. albopictus). The accumulation of rainwater in other containers and items of debris in the affected areas may also become Aedes breeding sites.
As these mosquitoes bite during daytime, insecticide-treated nets to sleep under will offer little or no personal protection.
Prevention of mosquito breeding in drinking water containers, by covering them to exclude mosquitoes, frequently emptying them (at least once per week), or treating them with insecticide, e.g., temephos 1% sand granules, will contribute to the prevention of dengue outbreaks. However, this may not be sufficient in settlement areas where there are small, freshwater collections in other artificial containers and miscellaneous debris. Depending on feasibility, chemical larvicides may also be applied to these containers. Application of insecticidal space sprays against the adult Ae. aegypti mosquitoes may also be warranted in settlement areas where there are larval habitats or where dengue transmission is occurring. Portable equipment will be needed in areas with difficult road access. To the extent possible, affected populations may be provided with mosquito repellents. The use of space sprays and of repellents will also contribute to temporary relief from the discomfort caused by nuisance mosquitoes.
Surveillance for dengue fever and dengue haemorrhagic fever should be included in the post-disaster surveillance system. Hospital facilities should be prepared to respond in the event of outbreaks.