Environmental and Social Conditions Prevailing Dengue Fever Outbreak in Pasir Mas District, Kelantan State, Malaysia, 2010

Abstract

A dengue outbreak occurred in Pasir Mas District, Kelantan, Malaysia during 2010. We conducted an investigation to describe the clinical and epidemiological characteristics of cases, determine risk factors for transmission and recommend appropriate control measures. A dengue case was defined as an individual with acute febrile illness and two or more of the following symptoms: rash, arthralgia, headache, myalgia, retro-orbital pain, hemorrhagic manifestation or leucopenia. Environmental surveys were done to search for Aedes species. A matched case-control study was done. From 5 May to 12 Aug 2010, total 465 cases were identified, with male to female ratio as 1.2:1. Most cases (34%) belonged to 11-20 years old group, followed by those aged 21-30 years (14%). Cases were mostly students (40%) or rubber tappers (15%). Aedes aegypti and Aedes albopictus species were identified in the district while many cases resided in areas with Aedes index of more than 1% and breteau index of more than 5%. Risk factors for getting dengue infection were presence of discarded containers within household premises (adjusted OR = 15.1, 95% CI = 5.41-41.97) and not using protective measures (adjusted OR = 3.9, 95% CI = 1.21-12.55). Control activities focused on mass clean-up and health education campaigns in affected communities. As a conclusion, this outbreak involved active individuals, and contributed by presence of breeding containers and not using personal protective measures.