00000000Since dengue became notifiable, there are data to suggest that major outbreaks of dengue occur every four years (1974, 1978, 1982, 1986). The dengue activity in 1986 appeared to spill over into 1987 when 2002 cases were notified with seven deaths.
A recent age stratified survey based on 5138 specimens collected from one dengue sensitive study site in Malaysia showed that children under one year of age had antibody to one or more dengue serotypes and that this declined to 8.6 per cent at one year due to loss of maternal antibody(26). The antibody prevalence then increased by an average of five per cent every year until the age of 18 when all subjects tested were positive. Of the 2620 males and 2416 females studied, there was no significant difference in antibody prevalence between the two sexes.
A socio-demographic survey and a survey on knowledge, attitude and practices of the study population were carried out. The data were analysed against the serological findings and the following were noted:

• Children from smaller families had lower antibody prevalence than those from large families.
  
• There was no difference in antibody prevalence based on income analysis.
  
• Twenty-eight per cent of children from families with good knowledge of the disease had antibodies to dengue compared to 51 per cent of those from families with little knowledge.
  
• Although piped water was available, 80 per cent of the households surveyed stored water in open containers.
  
• Children from homes with receptacles and containers in which mosquitoes could breed had a higher prevalence of antibody.
  
• Antibody prevalence was related to the A. aegypti Breteau and Premise indices.

00000000The epidemiology of dengue in Malaysia is related to two rainy seasons, the SW monsoon in the first half of the year and the NE monsoon in the second half of the year. The endemicity is low from January to April and increases, reaching a peak in July/August. Smaller peaks may appear between October and November. This variation may be related to the storage of water during the drought season from January-April and the drizzling rainfall before the heavy monsoons, which create suitable breeding places for the vectors.