A new zoonotic visceral leishmaniasis dynamic transmission model with age-structure

• Published in: Chaos, solitons and fractals solitons and fractals, 2020-04, Vol.133, p.109622, Article 109622
• Main Authors: Bi, Kaiming, Chen, Yuyang, Zhao, Songnian, Ben-Arieh, David, (John) Wu, Chih-Hang
• Format: Article
• Language: English
• Subjects: Age structure; Dynamic transmission; Epidemic; Partial differential equation; Zoonotic visceral leishmaniasis
• ISSN: 0960-0779; 1873-2887
• DOI: 10.1016/j.chaos.2020.109622

•PDE model was introduced to describe ZVL transmission with age composition of human.•Equilibrium, bifurcation and sensitivity analysis were discussed for the PDE system.•Simulation for multiple countries predicted the global ZVL epidemic in 2018–2021. Visceral leishmaniasis (VL) is a fatal, neglected tropical disease primarily caused by Leishmania donovani (L. donovani) and Leishmania infantum (L. infantum). According to VL infectious data reports from severely affected countries, children and teenagers (ages 0–20) have a significantly higher vulnerability to VL infection than other populations. This paper utilizes an infected function (by age) established from epidemic prevalence data to propose a new partial differential equation (PDE) model for infection transmission patterns for various age groups. This new PDE model can be used to study VL epidemics in time and age dimensions. Disease-free and endemic equilibriums are discussed in relation to theoretical stability of the PDE system. This paper also proposes system output adjustment using historical VL data from the World Health Organization. Statistical methods such as the moving average and the autoregressive methods are used to calibrate estimated prevalence trends, potentially minimizing differences between stochastic stimulation results and reported real-world data. Results from simulation experiments using the PDE model were used to predict the worldwide VL severity of the epidemic in the next four years (from 2017 to 2020).