Factors associated with dengue outbreaks in Pulau Pinang, Malaysia from the eDengue Database: A cross-sectional study

Dengue is now endemic in over 100 countries, with Asia bearing over 70% of the global burden. In Malaysia, dengue cases have increased dramatically, particularly in Pulau Pinang, where cases rose from 1621 in 2022 to 7343 in 2023. This study aimed to examine factors associated with dengue outbreaks in Pulau Pinang in 2023 by comparing outbreak cases with single cases.

This is a cross-sectional study using eDengue database, the Malaysian National Dengue Registry.

The study included 1106 confirmed dengue cases, with 553 categorised as outbreak cases and 553 as single cases. Significant associations were found between dengue outbreaks and Priority Locality 1 (areas with Uncontrolled Outbreaks/ Hotspots/ Recurrent Outbreaks/ Dengue Deaths in the previous year) (aOR: 0.15, 95% CI: 0.06,0.37, p<0.001), Aedes Index ≥1% (aOR: 1.35, 95% CI: 1.02,1.77, p=0.031), patients initially visiting government clinics (aOR: 1.63, 95% CI: 1.10,2.43, p=0.015), hospitalized dengue patients (aOR: 0.70. 95%CI: 0.52,0.96, p=0.029), the time taken from notification to source reduction (aOR: 0.57, 95% CI: 0.50,0.66, p<0.001) and time taken from notification to investigation (aOR: 2.40 95%CI: 1.77,3.24, p<0.001).

This study identifies key factors associated with dengue outbreaks in Pulau Pinang such as Aedes Index, Priority Locality 1 areas and initial visits to government clinics. These findings underscore the need for targeted vector control and early intervention in high-risk areas to reduce outbreak risk. Early healthcare seeking behavior and timely intervention are critical in managing the spread of dengue. Further research is needed to explore additional factors and improve public health strategies.