Trends of dengue infections in Malaysia, 2000-2010

To analyze trends of dengue incidences and deaths in Malaysia from 2000 to 2010 as well as the predominant dengue virus serotypes during the last decade.

We used the national data on annual reported cases, deaths, incidence rate, mortality rate, and case fatality rate of dengue fever (DF) and dengue hemorrhagic fever (DHF) as well as dengue virus serotypes prevalent in Malaysia during the last decade. Trend/ regression lines were fitted to investigate the trend of dengue incidences and deaths due to the disease for a 11-year period (2000-2010). For the distribution of national incidence rate, mortality rate, and case fatality rate of DF and DHF, descriptive statistics using mean and 95% confidence intervals (CI 39) for means, and range were applied.

The number of dengue cases and number of deaths have increased, on average, by 14% and 8% per year respectively. The average annual incidence rate of DF per 100 000 populations was higher as compared to that of DHF. Conversely, the yearly mean mortality rate of DHF per 100 000 populations was greater than that of DF. The simultaneous circulation of all four dengue serotypes has been found in Malaysia. But a particular dengue virus serotype predominates for at least two years before it becomes replaced by another serotype.

The dengue situation in Malaysia has worsened with an increasing number of reported cases and deaths during the last decade. The increasing trend of dengue highlights the need for a more systematic surveillance and reporting of the disease.