Background. Tuberculosis (TB) is one of the top ten causes of death worldwide. The World Health Organization adopted the “End TB Strategy”, whose goal is to end the global TB epidemic by 2035. However, achieving this goal will be difficult using current prevention and control measures.
Methods. A Susceptible-Exposed-Infectious-Recovered (SEIR) model that distinguishes drug-sensitive (DS) and drug-resistant (DR) TB in the entire Chinese population was established. Goodness-of-fit tests and sensitivity analyses were used to assess model performance. Predictive analysis was performed to assess the effect of different prevention and control strategies on DR-TB and achieving the goal of the End TB Strategy: 90% fewer cases of DR-TB by 2035.
Results. We used parameter fitting to determine the basic reproduction number of the model as R0 =0.6993. Chi-square test results indicated good model fits for the reported incidences of DS-TB (χ2=0.144, P=1.000) and DR-TB (χ2=0.076, P=1.000). The predictive analysis led to four major projections for the number of cases by 2035. First, if the transmission rate of DR-TB patients reaches 0 during the infectious period, there will be 208,754 fewer cases (failure to achieve to goal). Second, if the progression rate of latently infected people reaches 10%, there will be 255,075 fewer cases (92.2% lower than in 2015). Third, if the overall treatment and cure rate of patients with DS-TB improves to 100%, there will be 150,482 fewer cases (failure to achieve the goal). Fourth, if the cure rate of DR-TB increases to 40%, there will be 253,198 fewer cases (91.5% lower than in 2015).
Conclusions. We assessed several prevention and control measures for DR-TB. Interventions that target acquired DR and improvement of the cure rate of DS-TB have limited efficacy. However, interventions that target primary DR-TB, such as reducing the probability of transmission and the rate of disease progression in patients with DR-TB, have better efficacy. Improving treatment compliance and the cure rate of patients with DR-TB can also contribute to attaining the goal of the End TB Strategy.