Estimating the basic reproduction number for single-strain dengue fever epidemics

Area of Science:

• Epidemiology
• Mathematical Biology
• Infectious Disease Modeling

Background:

• Dengue fever is a significant global mosquito-borne viral disease.
• The 2011 Pakistan dengue epidemic provides a case study for disease transmissibility analysis.
• Understanding dengue's spread is crucial for public health interventions.

Purpose of the Study:

• To assess dengue transmissibility during the 2011 Pakistan epidemic.
• To estimate the basic reproduction number (R0) using diverse methodologies and models.
• To evaluate the robustness of R0 estimates across different analytical approaches.

Main Methods:

• Retrospective analysis of the 2011 dengue epidemic data in Pakistan.
• Fitting deterministic ODE vector-host and direct-transmission models using Ordinary Least Squares (OLS) and Generalized Least Squares (GLS).
• Formulating a direct-transmission stochastic model and employing Markov Chain Monte Carlo (MCMC) for parameter estimation.

Main Results:

• Initial R0 estimates exceeded unity, indicating epidemic potential.
• Implemented control measures effectively reduced R0 below one, leading to disease elimination.
• Strong agreement was found for pre-control R0 estimates across models and methods.
• Significant discrepancies were observed in post-control R0 estimates between the two models.

Conclusions:

• Robust R0 estimates were obtained for the pre-control phase of the 2011 dengue epidemic.
• Close agreement exists for post-control R0 estimates across different methodologies.
• Differences in post-control R0 estimates highlight model-specific variations in assessing intervention impact.