Medical Journal of Malaysia

MJM, Vol 70 Supplement 1 September 2015

Dengue Vector Density in Outbreak Localities of Section 7, Shah Alam, Selangor

Ahmad Nadzri J*, Mohd Hazrin H*, Norzawati Y*, Faizah P*, Jamsee O*, Sayan P*, Khadijah K**, Ahmad J**, Tee Guat Hiong*

*Institute for Public Health, Ministry of Health Malaysia, **Petaling District Health Office, Ministry of Health Malaysia


Introduction: Dengue fever infection will only happen when these three components which are virus (flavivirus), vector (aedes mosquitoes) and host (human) occur in a same place at the same time. The infection cannot occur if one of the components such as vector is not present. Therefore vector surveillance can be used as a tool for determining the risk for dengue infection to occur. The objective of the study was to determine the presence of the dengue’s vector and predicting its impact on the localities.

Methods: Section 7 Shah Alam Selangor was chosen for the study because of the high number of dengue cases registered in 2014 (1450 cases) with 21 outbreak localities. Vector surveillance was carried out by installing ovitrap after the episode ended in all the outbreak localities. Information about the outbreak localities such as number of dengue cases, number of epidemic localities, number of episodes of the epidemic and the duration of an epidemic episode were obtained from the ‘eDengue. ‘eDengue’ is the dengue surveillance system used by the Disease Control Program, Ministry of Health Malaysia.

Results: All 21 outbreak localities showed positive ovitrap index. Five localities had ovitrap index of more than 30%, fifteen localities showed between 10%-30% and one locality had 8%. Four localities showed the presence of both Aedes species, Aedes aegypti and Aedes albopictus outdoor. One locality showed the presence both Aedes species, Aedes aegypti and Aedes albopictus outdoor plus Aedes albopictus indoor. The remaining 16 localities indicate only Aedes albopictus out door.

Conclusion: Dengue vector could still be found especially in outdoor area after the outbreaks had ended. As such, all epidemic localities in section 7 Shah Alam is at risk of becoming an epidemic again. Therefore, destroying the breeding places of mosquito outside the premises should be emphasised.

Keywords: dengue, vector surveillance, ovitrap, outbreak, Seksyen 7 Shah Alam