Assessing the dengue vector breeding characteristics in Sibu district, Sarawak, Malaysia using cluster analysis

Dengue fever that are caused by dengue virus has currently emerged as one of the major threats to public health in Malaysia. The incriminated vector species for the diseases were caused by Ae. aegypti and Ae. albopictus. This study was initiated to determine the effect of size of breeding containers that contribute towards the development of Aedes immature abundance in urban residential areas in Sibu District, Sarawak, Malaysia. The study areas were divided into high-risk areas and low-risk areas. Therefore, cluster analysis was utilized by using self-organizing map (SOM) to visualize, partitioning and mapping the Aedes immature abundance in relation with different size capacity of the containers in the selected areas. In addition, limited studies were conducted to explore and visualize the multi-variable data by using SOM technique toward dengue vector abundance. Accordingly, majority of the studies have proposed the distribution pattern of the dengue vector abundance based on statistical analyses. For statistical analyses such as Chi-Square and Kruskal-Wallis test were also done to evaluate the abundance pattern of potential breeding containers in relation with the prevalence of Aedes immature stages. Based from the results, the Chi-Square indicated that there was statistical difference between the number of potential breeding containers and size (p < 0.05). The Kruskal-Wallis test indicated that there were no statistically significant associations were found among both of the study areas (p > 0.05) for Ae. aegypti and Ae. albopictus in the number of breeding abundance. The results from the unsupervised clustering techniques indicated that Ae. albopictus contributed strongly to the Aedes mosquito abundance for both areas identified in Sibu District, Sarawak. The abundance of the Aedes immature stages mainly occur in the class of large containers in low-risk areas whereas for high-risk areas, in the class of small containers for both species identified. The findings indicated a need to take action by eliminating the breeding containers which subsequently reducing the distribution of the Aedes immature stages for dengue control efforts and preventing dengue fever.