Dengue fever – Sri Lanka
Disease Outbreak News
19 July 2017
From 1 January to 7 July 2017, the Epidemiology Unit of the Ministry of Health (MoH) Sri Lanka reported 80 732 dengue fever cases, including 215 deaths. This is a 4.3 fold higher than the average number of cases for the same period between 2010 and 2016, and the monthly number of cases exceeds the mean plus three standard deviations for each of the past six months. Based on sentinel site surveillance for the past seven years the expected peak months of May to July coincides with the south-western monsoon which commences in late April.
Approximately 43% of the dengue fever cases were reported from the Western Province and the most affected area with the highest number of reported cases is Colombo District (18 186) followed by Gampaha (12 121), Kurunegala (4889), Kalutara (4589), Batticaloa (3946), Ratnapura (3898), and Kandy (3853). Preliminary laboratory results have identified Dengue virus serotype 2 (DENV-2) as the circulating strain in this outbreak. Although all four DENV have been co-circulating in Sri Lanka for more than 30 years and DENV-2 has been infrequently detected since 2009.
The current dengue fever outbreak occurs in a context of massive heavy rains and flooding and is currently affecting 15 out of 25 districts in Sri Lanka where almost 600 000 people have been affected. Heavy monsoon rains, public failure to clear rain-soaked garbage, standing water pools and other potential breeding grounds for mosquito larvae attribute to the higher number of cases reported in urban and suburban areas.