Two Decades of Dengue in Malaysia

Abstract

Dengue is endemic in Malaysia and the first case was documented in 1902. The disease was made notifiable in 1973 and the first outbreak of dengue haemorrhagic fever was reported in 1962. During the decade of 1973-1982, there were 12,077 dengue cases with a case fatality rate of 3.38%. In the following decade of 1983-1992, the number of reported cases increased to 26,361 but the case fatality rate dropped to 0.55%. The increase in incidence could be due to rising economy, rapid industrialization and urban migration. The reduction of case fatality rate could be due to patients seeking early medical treatment and to better case management. Based on 6,970 laboratory confirmed cases since 1983, the male to female ratio was 1.2: 1 and the ratio among the three major ethnic groups (Chinese: Malays: Indians) was 5.1: 2.9: 1. All four dengue serotypes are present in Malaysia but one serotype usually predominates for at least two years. The case fatality rate for dengue 3 outbreak is highest (0.77%), followed by dengue 2 (0.54%) and dengue 1 (0.35%). From our experince in the last two decades, it is possible to predict the severity of dengue outbreaks based on the circulating predominant serotype. The dengue situation in Malaysia during the last two decades has worsened with an ever increasing number of reported cases. Vector control measures have not been successful and it is unlikely that the situation will improve in the next decade. The only solution is through dengue vaccination which hopefully will come about in the not too distant future