Unraveling Lassa Fever Persistence: A Compartmental Model with Environmental Virus-Host-Vector Interaction

Lassa fever (LF), a severe viral hemorrhagic disease transmitted by rodents, particularly Mastomys natalensis, is endemic in West Africa, notably Nigeria, with substantial morbidity and mortality rates. Existing mathematical models on LF lack integration of the crucial environmental component, overlooking transmission through contaminated surfaces. Moreover, none address vertical transmission or the seasonal migration of humans and rodents, factors contributing to observed seasonal patterns. Our ongoing project aims to fill these gaps, with preliminary results emphasizing the efficacy of LF control measures focusing on systematically eliminating virus contamination from surfaces, leading to a notable reduction in the reproduction number (by approximately 75%) and incidence in both vector and human populations by over 95%. These results may explain the observed decrease in LF cases in 2021 due to stringent surface-cleaning COVID-19 measures implemented in 2020. Even in scenarios where surface cleaning is challenging, controlling rodent vital rates can still effectively manage LF.