Analyzing Policymaking for Tuberculosis Control in Nigeria

Figure 1

The model: a compartment model for tuberculosis transmission in Nigeria. The model shows the dynamic flow of tuberculosis (TB) including susceptible population ; the latently infected population are discerned based on the time since they were infected; therefore stands for people latently infected for a period of one year, stands for people infected for 2 years, etc.; stands for people that have been infected for more than 7 years; two types of the nondiagnosed sick population are considered, and , and the sick under treatment is shown as . Birth occurs at constant rate . Transmission of Mtb depends on and probability leading to active TB is given as , where is the year of infection. indicate succession from one infected compartment to the next. A fraction of the sick, , will be detected and notified; is related to diagnosis time delay before starting treatment and indicates a fraction of relapse for the sick under treatment. Recovery rate is given as while represents the fraction of the infected population that gets rid of the disease spontaneously. We account for all courses of death, , , , and , and death due to active TB, .