Cluster analysis of spatial and temporal distribution of dengue disease in Sri Lanka from 2012 to 2017

Dengue is a vector borne disease that has been neglected over many years. It is the most rapidly spreading mosquito borne disease, currently present in most tropical regions in the world. Sri Lanka is one of the worst affected countries with an increasing number of dengue cases recorded every year. In Sri Lanka, the highest number of confirmed cases in a year was reported last year, in 2017. Due to non-existence of a specific treatment or a vaccination, the controlling strategies are only technique to reduce the dengue risk. Therefore, understanding the patterns of the dynamics that influence the dengue disease is of utmost importance to identify the effective control strategies. In this study, the current situation of dengue in Sri Lanka is analyzed in relation to the population density of each district using clustering. Through results, it is observed that there is a strong relationship between the population density and the number of dengue cases reported from 2012 to 2017 in Sri Lanka. Further, in every year, there exist four distinct clusters when population density and dengue cases were clustered. It was also observed that the districts always belonged to the same cluster, with an exception of Kurunagala and Rathnapura districts moving between adjacent clusters in 2012 and 2017. The geographical mapping of the clustered results also indicates a pattern, Colombo being the center with the highest dengue intensity, around which other districts are arranged in decreasing order of the same, Jaffna being the only exception.