00000000In 1976, a World Health Organization (WHO) short-term consultant was sent to develop a surveillance system. A small scale serological survey revealed that dengue virus was present in many parts of the country.

00000000During 1982 - 83, a survey was carried out among school children in Dhaka Metropolis. Of 2465 blood samples taken, 278 were found positive for dengue 1 (DEN-1) infection by the HI test(3).

00000000From May 1983 to April 1984, ovitrap surveys (one indoors in houses and ten outdoors) were carried out in Dhaka city to detect the presence and prevalence of Aedes aegypti and Aedes albopictus. These surveys were carried out both in the old and new areas of the city. Of the 23 areas sampled, 22 have a positive result. The A. aegypti index was 16.2 and the A. albopictus index was 5.3. These indices were definitely low. The number of mosquitoes in the traps was also exceedingly low (A. aegypti per trap = 4.6;A. albopictus per trap = 9.48). The A. aegypti index in indoor ovitraps was 13.84 and that for A. albopictus was 2.74. Comparatively higher indices were found outdoors (A. aegypti = 20.03; A. albopictus = 9.58). More ovitraps were found positive in the congested old city areas where the water supply is sporadic and irregular. In these areas the sanitation is also poor and collection of water in gutters, discarded tins, old tyres, etc., is common. The low density of probable vector mosquitoes in said to be the cause of the absence of severe forms of dengue.

00000000During the period 1984 - 1986, 21 blood samples were collected from the shishu (children's) hospitals and the Sir salimullah Medical College Hospital, and three were found positive by the HI test. It is unfortunate that regular monitoring of the Aedes index, the collection of statistics of clinical cases of DHF, and the taking of serological blood samples are not carried out by the medical institutions of the four major cities,
Up to 1986, the major cities of Bangladesh, namely Dhaka, Chittagong, Rajshahe and Khulna, were free of dengue haemorrhagic fever(3).

Myanmar

00000000A dengue-like illness has been reported in Yangon (formerly Rangoon) since 1954. An epidemic of dungue-like disease with marked arthralgia occurred in Yangon and several parts of the country in 1963(4). Since 1965, the Central Epidemiology Unit has been documenting the number of DHF cases admitted to hospital (Table 1)(5). There is some serological evidence to suggest the presence of chikungunya virus infection. Serological stuties conducted in Yangon in 1968 revealed that 79 per cent of children under 12 years of age had antibody to dengue virus type 4 (DEN-4) and lower percentages had antibody to dengue types 3, 2 and 1.

Table 1. Number of hospitalized cases of dengue haemorrhagic fever in Burma from 1965 to 1978

CFR = Case fatality rate.