School-based interventions to control dengue vector in the Gampaha district

Abstract

This study was conducted to determine the effectiveness of school-based interventions to control dengue vectors in the Gampaha District, Sri Lanka. Sixty schools were selected randomly from the school registry in four selected educational zones (15 each) as interventional (Kelaniya and Gampaha) and control (Negombo and Minuwangoda). A baseline and three follow-up entomological surveys were conducted in all selected schools at 6-months intervals during 2016-2018. The intervention consisted an activity plan with entomological field surveys, larval control interventions followed by a structured awareness programme of dengue covering general epidemiology, clinical symptoms, prevention, vector control and waste management. Focus group discussions were conducted with stakeholders at 30 intervention schools to identify limitations in current control approaches. The level of awareness of dengue disease was assessed before and after the awareness programme using a structured questionnaire. Awareness levels were categorized as very poor (< 20%), low (21-40%) moderate (41-60%), good (61-80%) and excellent (> 80%). The change in awareness level was determined using General Linear Model. The effectiveness of the vector control interventions were assessed by the total number of dry, water-holding, and infested containers at follow-up survey compared to the baseline. Over, 46.31% (n=1016) of students had good level of awareness prior to the structured awareness programme and reached to the excellent level (41.84%; n=918) after the awareness programme. The improvement of the awareness level was identified as statistically significant according to the chi-square test of independence. At the base-line survey, Aedes albopictus was the predominant species in both control (60%; n=18) and intervention (63.33%; n=19) groups. Leaf axils were the leading breeding habitat followed by discarded plastic and metal containers in the control group. The number of discarded containers was reduced drastically in the interventional schools in the follow-up surveys. There was a statistically significant difference in dry (p<0.001), water-holding (p=0.027), and infested (p=0.006) containers after the last follow-up survey at interventional schools compared to the controls. This study warrants the need of sustainable participation of school community for dengue control. Therefore, strengthening Environmental Pioneer Programme will improve the capacity in dengue control interventions.