Seasonal Distribution and Climatic Correlates of Dengue Disease in Dhaka, Bangladesh

Dengue has been regularly reported in Dhaka, Bangladesh, since a large outbreak in 2000. However, to date, we have limited information on the seasonal distribution of dengue disease and how case distribution correlates with climate. Here, we analyzed dengue cases detected at a private diagnostic facility in Dhaka during 2010-2014. We calculated Pearson cross-correlation coefficients to examine the relationship between the timing of cases and both rainfall and temperature. There were 2,334 cases diagnosed during the study period with 76% over the age of 15 years. Cases were reported in every month of the study; however, 90% of cases occurred between June and November. Increases in rainfall were correlated with increases in cases 2 months later (correlation of 0.7). The large proportion of adult cases is consistent with substantial population susceptibility and suggests Dhaka remains at risk for outbreaks. Although cases occurred year-round, public health preparedness should be focused during peak months.