Understanding Rabies Transmission Dynamics and Control in the Three Administrative Districts of Davao City Using a Modified SEIV Model

Abstract

Despite the control programs of the City Veterinarian’s Office (CVO), rabies is still geographically widespread across Davao City. Hence, a modified SEIV model incorporating different control strategies and adding population compartments focusing on reported rabies cases was formulated to understand dog rabies transmission dynamics. The model was fitted to the datasets of CVO from 2006–2020, such as the cumulative monthly positive rabies cases and the number of examined positive rabies samples in Talomo, Buhangin, and Poblacion districts. Results showed that the Talomo district had the highest rabies transmission rate but the lowest castration rate. On the other hand, the Poblacion district had the highest impounding rate and castration rate but the lowest birth and vaccination rate. Finally, the Buhangin district had the highest birth rate and vaccination rate but the lowest impounding rate and transmission rate. Sensitivity analysis (SA) was performed on over 10,000 samples of parameter space by the LHS method to obtain PRCC values. Results of the SA revealed that dog vaccination had a significantly strong influence among many interventions in mitigating rabies transmission – consistently in Talomo, Poblacion, and Buhangin districts. The results obtained in this study support the CVO’s ongoing mass canine rabies vaccination campaign in the city as a method of rabies control. Despite this, dog population control strategies (i.e. castration and impounding) must still be implemented in addition to intensifying vaccination strategy, as the birth rate also strongly contributes to increasing rabies transmission. Through the model and data fitting approaches, this study has provided information on the level of control measures implemented in three districts and can also be utilized to develop future rabies epidemiological models in Davao City and other locations.