Thiourea Derivatives: A Promising Class Against HIV/TB Co-Infection

Nowadays, the Human Immunodeficiency Virus (HIV), which is the causative agent of Acquired Immune Deficiency Syndrome (AIDS), represents a serious public health problem. According to the World Health Organization (WHO), in 2009 there were 33.3 million people living with HIV worldwide, and more particularly in sub-Saharan Africa, where the overwhelming majority (67%) of cases appear. Furthermore, 2.6 million people have been recently infected with the virus in 2009, when HIV/AIDS was estimated to have caused 1.8 million deaths (United Nations Program on HIV/AIDS [UNAIDS], 2010). Due to the impairment of their immune system, HIV bearers are more susceptible to opportunistic infections, such as Tuberculosis (TB), which is a leading cause of HIV-related deaths worldwide. The risk for TB is 20-37-fold greater among HIV-infected individuals, depending on the status of the HIV epidemic. According to WHO, one-third of people living with HIV are infected with TB, and there was an estimate of 1.4 million new TB cases per year among said population. Moreover, one in four TB deaths occurs in HIV-positive patients, while TB was responsible for 23% of AIDS-related deaths (WHO, 2010a). This situation becomes especially alarming in view of the number of challenges in the control and management of TB in HIV-infected individuals, such as the difficulties to conclude a TB diagnosis, as well as the complexity involved in the treatment of HIV infection-related TB. Due to their great relevance to the subject matter of this work, the above factors will be emphasized in the next section.