“…By forming epidemic models, one mainly tries to simulate and reveals the nature of epidemics and provides theoretical rules and results for preventing and controlling diseases (www.nncc626.com/2016-02/18/c 128731173 2.html., www.nncc626.com.) (Cen, Feng, & Zhao, 2014;Fang, Li, Martcheva, & Cai, 2014;Feng, Cen, Zhao, & Velasco-Hernandez, 2015;Huo, Chen, & Wang, 2016;Mulone & Straughan, 2009;Mushanyu, Nyabadza, & Stewart, 2015;Nyabadza, Njagarah, & Smith, 2013;Saha & Samanta, 2019a, 2019bSamanta, 2011;Samanta, Sen, & Maiti, 2016;White & Comiskey, 2007). White and Comiskey (2007) first studied a simple heroin model where the authors divided the total population into susceptible, heroin addicts who were not in treatment and heroin addicts who were under treatment.…”