ABSTRACT
The Human immunodefi ciency virus (HIV) infection for almost the past three decades, has continued to be one of the greatest intriguing health challenges of the century. From its discovery in 1981 to 2006, HIV/AIDS has claimed the lives of more than 25 million people of the global population. Even though not fully proven, HIV is thought to have originated in non-human primates in sub-Saharan Africa and was transmitted to humans late in the 19th or early in the 20th century (Worobey et al. 2008). The condition was fi rst clinically observed between late 1980 and early 1981. Various studies have confi rmed that injection drug users and ‘gay’ men with no known cause of impaired immunity showed symptoms of Pneumocystis carinii pneumonia (PCP), a rare opportunistic infection that was known to present itself in people with severe compromised immune systems (Masur et al. 1981).
