Modelling Chlamydia Trachomatis Infection Among Young Women in Ghana: A Case Study at Tarkwa Nsuaem Municipality

Abstract

Chlamydia Genital infection has been a global health issue especially among most developing countries. Although, a lot of researchers have modelled CT infection to determine the impact of different intervals between Chlamydia infection and the development of Pelvic Inflammatory Disease (PID) on the cost-effectiveness of screening and the use of Chlamydia vaccine. This paper seeks to model the dynamics of Chlamydia Trachomatis (CT) infection among females who were diagnosed of vaginal discharge and the likelihood of developing PID complications. The model was formulated using a sexual network to explore the relationship between Chlamydia infection through diagnosed vaginal infection and PID. A sample of 147 females were diagnosed and screened of Chlamydia related symptoms on a routine check-up in the Tarkwa Nsuaem Municipality in the Western part of Ghana. Lyapunov functions was used to prove the necessary and sufficient conditions for Stability State of the system while Next Generation Method was also used to calculate the basic reproduction number (R0). The Stability Analysis of the Modified SIRS model shows that the system is locally and asymptotically stable at the Disease-Free Equilibrium (DFE) E0, when R0 1, the Endemic Equilibrium (EE) E*, was found to be locally and asymptotically stable at certain conditions. It was observed that, as the distribution increases sharply at a given contact rate (β) of 0.05, many of the patients were infected within the first three days as compared to when the contact rate was 0.001. Moreover, at contact rates (β) of 0.5, R0 was greater than one, this shows how CT infection spreads in the population using parameter values in Table 1. Thus, the effects of change in the various initial conditions of the parameters (λ) and (β) on vaginal discharge and PID infections, turn to increase sharply at a higher infection rate for the first ten days of infection especially with vaginal discharge and then become stable over a period of time. This confirms the incubation period which is usually 7 to 10 days of infection. The paper concludes that, young women aged 18-24 years are more at risk of Chlamydia Trachomatis infection if diagnosed of vaginal discharge or PID and suggest early medication which is highly subsidised will help curb the spread of CT infection in the Municipality.