Mathematical Assessment of Dengue Control Interventions in Cebu City, Philippines

Dengue remains a significant public health challenge in the Philippines, with Cebu City experiencing recurrent outbreaks. In this study, we utilized a modified SIR-SI dengue model to understand the transmission dynamics in Cebu City and to assess the impact of dengue control interventions. Parameters in the model were estimated using weekly reported dengue data obtained from the Philippines’ electronic Freedom of Information (eFOI) portal for the 20th to 52nd weeks of 2022. Our results indicate a substantial reduction in the reproduction number from 3.58, observed without any control measures, to 1.16 with the control interventions. Despite this reduction, the reproduction number remains above the critical threshold of 1, indicating a continued risk of outbreaks. Sensitivity analysis identified the mosquito biting rate and transmission rate as key parameters influencing dengue transmission. This suggests the need to enhance control interventions by focusing on reducing human-mosquito contact and lowering the mosquito population. We simulated dengue reduction scenarios with respect to two control measures: self-protective measures and vector control. The results reveal that implementing self-protective measures alone reduced hospitalized cases by 15.42%, while vector control measures led to a 49.38% reduction. Combining both strategies resulted in a substantial 98.6% reduction in hospitalized cases. These findings imply that the control interventions implemented in Cebu City during the 2022 dengue outbreak effectively reduced hospitalized cases (health-seeking individuals) by approximately 98.6%. To further reduce the number of infected individuals, the City government and regional health officials must enhance existing control measures by focusing on reducing human-mosquito contact and lowering the mosquito population through enhanced awareness programs.