Implications of the COVID-19 Lockdown on Dengue Transmission in Malaysia

Area of Science:

• Epidemiology
• Vector-borne disease control
• Public health interventions

Background:

• Large-scale human movement restrictions, such as COVID-19 lockdowns, can impact infectious disease dynamics.
• Dengue fever, a significant public health concern, is transmitted by Aedes mosquitoes.

Purpose of the Study:

• To evaluate the effect of COVID-19 lockdown measures on dengue transmission and vector populations.
• To compare dengue incidence during lockdown periods with historical data and predictive models.

Main Methods:

• Comparative analysis of weekly dengue incidences during lockdown against 2015-2019 data.
• Utilized a Seasonal Autoregressive Integrated Moving Average (SARIMA) model to simulate dengue trends without movement restrictions.
• Identified predominant mosquito species and correlated their occurrence with dengue incidence.

Main Results:

• Dengue incidence decreased significantly in the initial weeks of lockdown, falling below the SARIMA model's lower confidence level.
• The rate of dengue incidence decline was substantially steeper during lockdown compared to previous years and the simulated model.
• Dengue cases rebounded earlier than expected and exhibited exponential growth from the second stage of lockdown.
• Aedes albopictus was identified as the primary vector, showing a strong correlation with dengue incidence.

Conclusions:

• Movement restrictions effectively reduced dengue transmission in the short term.
• The predominant Aedes albopictus vector's behavior, potentially including diffusive effects, contributed to the accelerated resurgence of dengue incidence.
• Findings highlight the complex interplay between human movement, vector ecology, and dengue transmission during public health crises.