CHAPTER ONE
INTRODUCTION
1.1 Background to the Study
 There are 36.7 million (34.0 million – 39.8 million) people estimated to be living with Human Immunodeficiency Virus (HIV) Worldwide in 2015, with 15.7 million and 2 million of these being women and children younger than 15 years of Age respectively, with a global HIV prevalence of 0.8% (WHO, 2015). It has also been established as the leading cause of mortality among women of reproductive age worldwide, a major contributor to maternal, infant and child Morbidity and mortality (UNAIDS 2009; UNICEF, 2009). In 2015, it was estimated that 1.8 million pregnant women living with HIV in low- and middle-income countries, most especially in sub-Saharan Africa, gave birth but without treatment the infants are at risk as one third of children living with HIV die before the age of one year and over 50% die by the second year of life (UNAIDS, 2009).
Of all people living with HIV globally, 9% of them live in Nigeria, with the size of the population of Nigeria, this means 3.5 million people were living with HIV in 2015. (UNAIDS, 2014). Since the beginning of the epidemic in the mid-1980s, a total of 2,200,000 new HIV infections have been reported in 2014 (WHO, 2015). Most cases were adults over the age of 15 years. Nigeria is now the second largest HIV disease burden in the world with 3.2 million after South Africa which has 6.8 million burden of the disease though prevalence is stable at 3.4% (Federal Ministry of Health, 2013; Nigeria National Agency for the Control of AIDS, 2012). Ogun State has been rated as the state with the second highest prevalence rate of Human Immunodeficiency Virus (HIV) in the South-West zone of the country with the prevalence of the disease in the state, it was gathered, increased from 1.5 percent in 2003 to 3.1 percent in 2010 (UNAIDS, 2010).
Mother-to-child HIV transmission occurs intrauterine (during pregnancy), intra-partum (at birth) and during breastfeeding and it is the leading cause of infant mortality in Africa where 1700 children are infected each day principally by mother to child transmission (WHO & UNICEF 2013), without antiretroviral treatment, the risk of an infected woman transmitting the virus to her child is between 16 and 40% with breastfeeding contributing at least 10% risk of transmission (De Cock, Fowler, Mercier , de Vincenzi, Saba, Hoff,  et al, 2000). An effective Prevention of Mother to Child Transmissions (PMTCT) programme requires mothers and their babies to receive antenatal services and HIV testing during pregnancy, have access to antiretroviral treatment (ART), and practice safe childbirth practices and appropriate infant feeding.
In developing countries where replacement feeding is generally not feasible or safe, hundreds of thousands of infants acquire HIV infection during breastfeeding (Bhandari, Bahl & Mazumadar, 2000). While breastfeeding improves child survival especially in resource settings, breastfeeding by HIV infected women however increases the incidence of HIV infection among breastfed infants (Pilay & Kam Kuhn, 2001; Coutsouchis, Goga, Rollins & Coovadia, 2002;Chopra, Piwoz & Sengwai, 2002; WHO, 2006). Mixed feeding has also been established to be more risky for HIV transmission than exclusive breastfeeding, this is partially due to damage to the epithelial integrity of the infant intestine that facilitates entry of the virus and because of breast engorgement that increases the viral load in breast milk between 3 to 6 months (Goga, Rollins & Coovadia, 2002; WHO, 2009).
Breastfeeding remains a common practice in parts of the world where the burden of HIV is highest. The difficult dilemma faced by HIV positive mothers is whether to breastfeed their infants in keeping with cultural norms, knowing the risk of transmitting the virus through breastfeeding, or to pursue formula feeding, which also comes with its own set of risks including a higher rate of infant mortality from diarrheal illnesses, while reducing transmission of HIV (Kruger & Gericke, 2001; Iliff, Piwoz, Tavengwa & Clare, 2005; WHO & UNICEF, 2013).
Breast milk transmission of HIV can occur at any time during the entire duration of breastfeeding and the risk of late postnatal transmission which occurs after 2.5 months of age into breastfeeding is revealed to be 3.2 per 100 child (Bulterys, Ellington & Kourtis, 2010). Breast milk contains immunoactive cells, antiinfectious substances, immune globulins, cytokines, and complement factors, however, HIV has been found in breast milk from HIV-infected mothers as both cell-associated and cell-free particle. Increased maternal ribonucleic acid (RNA) viral load in plasma and breast milk is strongly associated with increased risk of transmission through breast-feeding, and it has been suggested that exclusive breast-feeding could be associated with lower rates of breast-feeding transmission than mixed feeding of both breast- and other milk or feeds, (WHO, UNFPA & UNAIDS, 2010). Transmission through breast-feeding can take place at any point during lactation, and the cumulative probability of acquisition of infection increases with duration of breast-feeding WHO (2009).
