Dengue haemorrhagic fever in Malaysia: a review

The historical background, epidemiology and changing pattern of clinical disease as seen in Malaysia is reviewed. The preliminary results of the longitudinal study of epidemiology of dengue in Malaysia is also presented. Studies led by Rudnick et al. over some 18 years have established that the disease is endemically transmitted by both Aedes aegypti and Aedes albopictus causing illnesses ranging from mild febrile episodes through classical dengue fever, dengue haemorrhagic fever and the dengue shock syndrome. The first epidemic occurred in 1962 in Penang, and the second major epidemic in 1974 in Selangor. From then on epidemics seem to occur every 4 years, i.e. 1978, and then in 1982. With increasing number of cases being seen from the end of 1985 and in 1986, and with the increasing numbers of positive virus isolates, another epidemic may occur this year. Though in the early years, mainly children were affected, recently more cases are being seen in 16-30 years age group. There is also a changing pattern in the clinical presentation of the cases. The clinician has to be aware of the various modes of presentation of this sinister disease. A high index of suspicion is needed for early diagnosis, as management is mainly symptomatic and there is no specific drug as yet to combat the shock and bleeding manifestations.