Modelling Infectious Diseases: SEIR-SEI Compartmental Model on Malaria

Infectious diseases such as bacterial, viral, fungal and parasitic diseases continue to have a significant impact on global health. Hence, knowledge on how infection spread, population vulnerable to it and factors that determine where and when these infectious diseases occur is crucial for improving clinical trials and proffer effective treatment. This research work seeks to model disease incidence of malaria using the SEIR-SEI compartmental model. Secondary data on the incidence of Malaria disease from the World Malaria Report for Nigeria for 2023, Coefficients from Macro trends, were used to study the behavior of the Compartmental SEIR-SEI model. The results from the study show that since R < 1, then disease-free equilibrium for malaria transmission can be achieved as the number of infected individuals eventually declines in the population. Our herd immunity threshold decreases to about 0.3582 at t = 4 which means that the number of infected individuals decreases as a result of increase in vaccination of the population from the onset of disease incidence. Nevertheless, there will always be new infectious viruses, bacteria, fungal and parasites with their corresponding outbreaks. However, Compartmental modelling on how infectious diseases progress in an epidemic can inform how effective intervention will be.