Mechanistic modelling of the large-scale Lassa fever epidemics in Nigeria from 2016 to 2019

• Published in: Journal of theoretical biology 2020-05, Vol.493, p.110209-110209, Article 110209
• Main Authors: Musa, Salihu S., Zhao, Shi, Gao, Daozhou, Lin, Qianying, Chowell, Gerardo, He, Daihai
• Format: Article
• Language: English
• Subjects: Data fitting; Lassa fever; Mechanistic modelling; Stability analysis
• ISSN: 0022-5193; 1095-8541
• DOI: 10.1016/j.jtbi.2020.110209

•We proposed a compartmental model with both human and rodent population to study the Lassa fever epidemics.•The model exhibits the phenomena of forward bifurcation that the stability between the disease-free equilibrium and the endemic equilibrium exchanges.•The model fits the Lassa fever epidemics from 2016-19 with same reconstructed rodent-borne transmission rate.•The estimated initial susceptibility increased across the epidemics from 2016 to 2019, which indicates the increase in the case prevalence rate. Lassa fever, also known as Lassa hemorrhagic fever, is a virus that has generated recurrent outbreaks in West Africa. We use mechanistic modelling to study the Lassa fever epidemics in Nigeria from 2016-19. Our model describes the interaction between human and rodent populations with the consideration of quarantine, isolation and hospitalization processes. Our model supports the phenomenon of forward bifurcation where the stability between disease-free equilibrium and endemic equilibrium exchanges. Moreover, our model captures well the incidence curves from surveillance data. In particular, our model is able to reconstruct the periodic rodent and human forces of infection. Furthermore, we suggest that the three major epidemics from 2016-19 can be modelled by properly characterizing the rodent (or human) force of infection while the estimated human force of infection also present similar patterns across outbreaks. Our results suggest that the initial susceptibility likely increased across the three outbreaks from 2016-19. Our results highlight the similarity of the transmission dynamics driving three major Lassa fever outbreaks in the endemic areas.