A mathematical epidemiological model of gram-negative Bartonella bacteria : does differential ectoparasite load fully explain the differences in infection prevalence of Rattus rattus and Rattus norvegicus?

摘要

We postulate that the large difference in infection prevalence, 24% versus 5%, in R. norvegicus and R. rattus,respectively, between these two co-occurring host species may be due to differences in ectoparasite andpotential vector infestation rates.Acompartmental model, representative of an infectious system containingthese two Rattus species and two ectoparasite vectors, was constructed and the coefficients of the forces ofinfection determined mathematically. The maximum difference obtained by the model in the prevalenceof Bartonella in the two Rattus species amounts to 4.6%, compared to the observed mean difference of19%. Results suggest the observed higher Bartonella infection prevalence in Rattus norvegicus comparedto Rattus rattus, cannot be explained solely by higher ectoparasite load. The model also highlights theneed for more detailed biological research on Bartonella infections in Rattus and the importance of theflea vector in the spread of this disease.