Prevalence of Aedes aegypti and Aedes albopictus and observations on the ecology of dengue haemorrhagic fever in several areas of Thailand
Pant, C.P.; Jatanasen, S.; Yasuno, M.
Southeast Asian Journal of Tropical Medicine and Public Health 4(1): 113-121
1973
ISSN/ISBN: 0125-1562 PMID: 4718121 Document Number: 60888
Surveys showed that Aedes aegypti (L.) has spread to all regions of Thailand, and it was recorded in all the towns and many villages examined. It was not, however, collected at the higher altitudes (1000-1700 m above sea level). A. albopictus (Skuse) was collected at all altitudes and had a more rural and suburban distribution. This species seems to occupy a different niche in the environment but one that overlaps partly with that of A. aegypti. Amongst the various indices of infestation of A. aegypti, the Breteau index (the number of water containers with larvae present per 100 houses) seemed to be the most sensitive and showed the widest range. This also gave a more quantitative level of infestation in relation to man. Dengue haemorrhagic fever occurred in all the areas where A. aegypti was present and many cases were reported where the Breteau index was higher than 50. Factors governing the onset of epidemics of dengue haemorrhagic fever are not known, and at present it is not possible to plan preventive measures efficiently. Rural areas will have to be included in any control programme. There is a need for the development of sensitive surveillance procedures, both serological and entomological, to predict epidemics so that economic and efficient vector control measures can be undertaken.