A mathematical model of the impact of crack-cocaine use on the prevalence of HIV/AIDS among drug users

We propose a dynamic model to study the impact of the introduction of crack-cocaine among illicit drug users, considering the population divided into susceptible to drug use, crack-cocaine users, intravenous drug users, and users of both types of drugs. With respect to HIV infection status each one of these classes can, in turn, be susceptible to or infected with HIV or have already developed full-blown AIDS. Simulations were performed considering different transmission intensities for both parenterally and sexually transmitted HIV in each class of drug use. Differential mortality rates for each class of drug use and of HIV infection status was also considered.