Transmission Dynamics of Lassa fever with Variability in Infectiousness and Awareness Levels

Classical mathematical models with enhanced 
flexibility have been used extensively to 
simulate and analyse the course and effect of 
intervention programmes on the dynamics of 
several infectious diseases. Lassa fever is one of 
such diseases whose outbreak is often witnessed 
in West Africa. This work presents a 
mathematical model that investigates the impact 
of awareness levels of susceptible individuals as 
well as the diagnosis and treatment of both 
symptomatic and asymptomatic individuals on 
the transmission dynamics of Lassa fever in a 
population. The model developed in this paper 
divided the host population into two: the human 
host population and the non-human primates 
(animal reservoirs). The total human host 
population was further sub-divided into eight 
human compartments according to the prevailing 
level of awareness, diagnostic status and the 
resulting treatment action plan. Our analysis 
showed that the model has a disease-free 
equilibrium (DFE), which is locally 
asymptotically stable whenever the reproduction 
number is less than unity. Numerical simulations 
of the model, using relevant demographic data 
from Nigeria, revealed that increasing the 
fraction of susceptible individuals with 
reasonable awareness will help in reducing the 
cumulative number of new Lassa fever cases. 
The simulation also suggests that increasing the 
fraction of symptomatic individuals that are 
diagnosed, isolated and treated will result in the 
reduction of the number of individuals infected 
with the disease in the population. However, the 
impact of diagnosis will be more positively felt 
if there are robust treatment and isolation