Analysis of mitigation strategies in three-age-group clustered pneumonia transmission dynamics

Pneumonia is a debilitating illness mostly prevalent among children under five, the elderly over 64, and individuals with pre-existing health conditions or weakened immune systems. Owing to the distinct transmission rates in different age groups, a 3-age-band clustered model is developed to capture the effect of inter- and age-group pneumonia transmission dynamics. The study established essential properties of the model, including positivity and boundedness of solutions, and the existence of steady states and the conditions under which the disease may be contained. Through global sensitivity analysis, it was observed that the processes described by parameters related to transmission and recovery rates were the most influential in changes in infection levels across all age groups. In addition, numerical results showed that interventions targeting the intermediate-age group are more effective in containing pneumonia infection in the population in the long term. Additionally, the results showed that while the intermediate age group is linked to high transmission of pneumonia, the children and elderly age groups experience a higher prevalence of the infection. However, by introducing interventions such as protective measures for the middle and elderly age groups, vaccination for children, and treatment across all three age groups, particularly focusing on treating a smaller number of middle-aged individuals, infection levels can be lowered, the time to peak infection values can be delayed, and the likelihood of eventual eradication can be enhanced.