Virtual Math. Colloq. Apr. 16 3:30pm

Friday, April 16th at 3:30pm, Virtual Room (Zoom Meeting ID: 824 5840 4119)

"Continuous-Time and Discrete-Time Models of Cholera Infections In Cameroon"
Professor Dr. Eric Ngang Che, Howard University of Louisville


Since 1991, Cameroon, a cholera endemic African country, has been experiencing large cholera outbreaks and cholera related deaths. The population of Cameroon and the reported cholera cases in Cameroon are censused at discrete-time annual intervals. In this talk, we use “fitted” continuous-time and discrete-time demographic equations (disease-free equations) to capture the total population of Cameroon, and then use fitted continuous-time and discrete-time low-high risk structured cholera mathematical models to study reported cholera cases in Cameroon from 1987-2004. For simplicity, our risk structured models have no spatial structure. The two risk structured cholera models have approximately the same value for and both predicted cholera endemicity in Cameroon. We use our fitted risk structured cholera models to study the impact of vaccination, treatment and improved sanitation on the number of cholera infections in Cameroon from 2004. Furthermore, we use our fitted models to predict future cholera cases. We obtain that each of the three strategies, vaccination and treatment, or vaccination and improved sanitation, or the combined strategy of vaccination, treatment and improved sanitation is capable of eliminating cholera in Cameroon with the combined strategy having the lowest value for the effective reproduction number,, and the highest percentage decrease in the number of cholera cases. The discrete-time cholera intervention strategies results confirm the results of the ODE model. However, the discrete-time model predicts a significant decrease in the number of cholera cases in a shorter period of cholera intervention (2004-2019) as compared to the ODE model’s period of intervention (2004-2022). Finally, using sensitivity analysis, we study the impact of our model parameters on the demographic threshold, basic reproduction number, effective reproduction number and on the total number of our model’s predicted cholera cases.