CHAPTER ONE
INTRODUCTION
The human immune deficiency viruses (HIV) are two species of lentivirus (a sub group of retrovirus) that causes HIV infection and over time acquired immune deficiency syndrome (AIDS). AIDS is a condition in humans in which progressive failure of the immune system allow life threatening opportunistic infection and cancers to thrive.(UNAIDS and WHO, 2007). Two types of HIV have been characterized: HIV-1 and HIV-2. HIV-1 is the virus that was initially discovered and termed both Lymphadenopathy associated virus (LAV) and human T- lymphotropic virus 3 (HTLV-III). HIV-1 is more virulent and more infective than HIV-2, (Glibert et al, 2003) and the cause of the majority of HIV infections globally. The lower infectivity of HIV-2, compared to HIV-1, implies that fewer of those exposed to HIV-2 will be infected per exposure. Due to its relatively poor capacity for transmission HIV-2 is largely confined to West African (Reeves and Doms, 2002).
In must cases, HIV is a sexually transmitted infection and occurs by contacts with or transfer of blood, pre ejaculate Semen and vaginal fluid. Research has shown (for both same sex and opposite- sex couples) that HIV untransmissable through condomless sexual intercourse if the Hiv positive partner has a consistently undetectable viral load. (Rodger et al, 2009; Eisinger et al, 2019) contaminated blood transfusions, hypodermic needle and from mother to child during pregnancy, delivery or breastfeeding (Rom and Markowitz, 2007). Some body fluids, such as saliva and tears do not transmit HIV (CDC, 2006).
The HIV attacks the body’s immune system specifically the CD4 cells (T cell), which helps the immune system fight off infections. Untreated, HIV reduces the number of CD4 cells (T cell) in the body, making the person more likely to get other infection, or infection related cancers. Over time, HIV can destroy so many of these cells that the body can’t fight off infections and disease. These opportunistic infections or cancer take advantage of a very weak immune system and signal that the person has AIDs, the last stage of HIV infection (CDC, 2017).
In topical and low income countries, HIV disease and AIDS is a major public health problem, socio-economic burden, and a serious treat to development. At the end of 2008, the joint United Nation program on HIV/AIDS (UNAIDS), estimated that globally there were 33.4 million of people living with HIV/AIDS. An estimated 2.7 million new infections, occurred, 2.3 million being adults and 430,000 been children under the age 15 years. About 67% of the total number of infected people live in sub-Saharan African an estimated 2.0 million deaths occurred during 2008.