Impact of COVID-19 Policies on the Post-pandemic Resurgence of Dengue Fever in Southeast Asia and Latin America

ABSTRACT Background Dengue fever, one of the most widespread mosquito-borne diseases, declined markedly during the early COVID-19 pandemic due to lockdowns and reduced mobility. However, the sharp resurgence in 2023 raised concerns about the long-term epidemiological effects of pandemic-era measures. This study examines the sustained impact of COVID-19 public health policies on dengue transmission across seven high-burden countries in Southeast Asia and Latin America. Methods Monthly dengue cases and COVID-19 policy indices from January 2020 to December 2023 were analyzed in seven countries with ≥2,000 dengue cases in 2020. Based on the Oxford COVID-19 Government Response Tracker (OxCGRT), countries were grouped as Strict COVID-Control (SCC: Singapore, China) or Less Strict COVID-Control (LSCC: Indonesia, Argentina, Brazil, Colombia, Mexico). Generalized linear models assessed lagged effects of the Stringency Index and policy sub-components, adjusting for climate and reporting bias. Findings Dengue cases declined by 41.3% (95% CI: 36.2–46.5; p < 0.001) in 2020 relative to pre-pandemic levels. In LSCC countries, public information and vaccination policies were significantly protective (β = −174,354; p < 0.001), reflecting indirect benefits of COVID-19 awareness infrastructure. In SCC countries, economic interventions showed mixed effects: debt relief reduced dengue risk (β = −0.783; p = 0.003), while income support increased it (β = 0.583; p = 0.003). Interpretation COVID-19 policies exerted lasting, heterogeneous effects on dengue transmission. Strengthening communication, vector control, and vaccination in LSCC settings, and maintaining vigilance and integrated surveillance in SCC settings, are crucial for sustainable dengue preparedness.