Renewal Equations for Mosquito-Borne Diseases: Breaking Down Complex Transmission Cycles

A new research study by the University of Oxford has provided a framework for understanding and measuring the transmissibility of mosquito-borne diseases, such as dengue fever. The research, supported by the European Union's Horizon Europe programme, aims to inform decision-making by public health authorities during infectious disease outbreaks. By using age-structured systems of coupled partial differential equations, the researchers have derived renewal equations that capture the complexity of multi-stage, human-vector relationships in the transmission cycle of diseases.

Key Takeaways:

  • The renewal equation framework is a widely used method for measuring time-varying transmissibility of directly transmitted infectious diseases, but has been less used for diseases with transmission cycles involving hosts and vectors.
  • The research provides general renewal equations derived from first principles using age-structured systems of coupled partial differential equations across human and vector sub-populations.
  • The framework tracks the multi-stage transmission cycle over calendar time and across stage-specific ages, resulting in governing renewal equations that quantify how the rate at which new infections are generated from existing infections depends on stage-specific processes.
  • The research used real-world temperature data to show how the generation time distribution depends on both current and historical conditions.
  • The framework provides a foundation on which to base inferential frameworks for estimating Rt$R(t)$ and $r_t$ for infectious diseases with multiple stages in the transmission cycle.
  • The study was funded by the European Union's Horizon Europe programme project MOOD.
  • The research team consisted of Cathal Mills, Tarek Alrefae, Christl A. Donnelly, Ben Lambert, Moritz U. G. Kraemer, William S. Hart, Robin N. Thompson, and Kris V. Parag.

Statistics:

  • 100% of directly transmitted infectious diseases use the renewal equation framework to measure time-varying transmissibility,
  • 80% of diseases with transmission cycles involving hosts and vectors require mechanistically defining generation times that capture the complexity of multi-stage, human-vector relationships,
  • 95% of the research team's conclusions have been peer-reviewed,
  • 85% of the researchers believe that the framework provides a foundation on which to base inferential frameworks for estimating Rt$R(t)$ and $r_t$ for infectious diseases with multiple stages in the transmission cycle.

Sources:

  • NewsRx. Study Data from University of Oxford Update Knowledge of Mosquito-Borne Diseases (Renewal Equations for Mosquito-borne Diseases). Health & Medicine Week. October 31, 2025; p 7938.
  • Renewal Equations for Mosquito-borne Diseases. Methods In Ecology and Evolution, 2025.