Factors determining dengue outbreak in Malaysia.

Area of Science:

• Medical Entomology
• Epidemiology
• Environmental Science
• Public Health

Background:

• Dengue outbreaks pose a significant public health challenge in Malaysia.
• Understanding the interplay of entomological, epidemiological, and environmental factors is crucial for effective control.

Purpose of the Study:

• To elucidate the relationships among entomological, epidemiological, and environmental factors contributing to dengue outbreaks in Malaysia.
• To develop a predictive model for dengue outbreak forecasting.

Main Methods:

• Large-scale field study over 81 weeks in high-incidence areas (Selayang and Bandar Baru Bangi).
• Entomological data collection using ovitraps for Aedes mosquito larvae and RT-PCR for dengue virus detection.
• Epidemiological data included notified cases and interventions; environmental data comprised rainfall, temperature, humidity, and air pollution index (API).
• Correlation and Autoregressive Distributed Lag (ADL) models were employed for analysis.

Main Results:

• Notified dengue cases showed indirect relationships with environmental factors, with a time lag of 1-4 weeks.
• Intervention timing was found to be delayed, allowing for dengue transmission.
• The ADL model achieved high prediction accuracy: 84.9% for Selayang and 84.1% for Bandar Baru Bangi.

Conclusions:

• A significant relationship exists among entomological, epidemiological, and environmental factors in dengue outbreaks.
• The developed ADL model can serve as an effective early warning system for predicting dengue outbreaks.
• Early implementation of preventive interventions based on such a system can help avert outbreaks.