The effect of reinfection with the same serotype on dengue transmission dynamics.

Highlights • We develop a multi-strain dengue model assuming reinfection with the same dengue serotype. • We found a novel criteria for the stability of endemic equilibrium. • The reinfection parameter contributes to an increasing number of primary and secondary infections. Abstract Dengue is worldwide problem with around 390 million cases annually. Dengue is caused by four dengue serotypes: DEN1, DEN2, DEN3, DEN4. Individuals obtain lifelong immunity to the serotype they are infected with. This becomes the main underlying assumptions of most modeling work on dengue. However, data from West Java, Indonesia, showed that there is a possibility for individuals to be reinfected by the same strain, which may result in significantly different dengue transmission dynamics. In this paper, we develop a novel multi-strain dengue model taking into account the reinfection with the same dengue serotype. We examine the effects of reinfection with the same serotype, study symmetric epidemiological characteristics and investigate the effects of antibody-dependent enhancement on dengue transmission dynamics by using a mathematical model. We analyse the stability of the model and perform global sensitivity analysis to determine the most influential parameters. We found that the model has four equilibrium points: disease-free, two partially endemic and coexistence equilibria. We also presented two Basic Reproductive Ratio R i associated with the first and the second strain of the viruses. The stability of the model is determined by the condition of basic reproductive ratio. We found that when the degree of immunity to the same strain, κ , is between zero and one, the existence of endemic equilibrium is determined by κ ℜ i , where ℜ i is the basic reproductive ratio. Furthermore, we found that reinfection with the same serotype contributes an increase in the number of primary and secondary dengue cases. The results suggest that it is likely that reinfection with the same serotype may be one of the underlying factors causing an increase in the number of secondary infection. [ABSTRACT FROM AUTHOR]