Laboratory testing to identify HIV infection has been used throughout the world for over 20 years, and continues to be a major intervention in protecting recipients of blood and tissues (Constantine et al., 2005). Serological screening of donor blood for HIV antibodies remains a critical component in identifying and eliminating HIV infected blood donations (Nkengasong et al., 1999) but, this test rarely detect HIV antigen positive blood donors who are in the window period.
Detection of this early viraemic stage continues to be a challenge in transfusion medicine worldwide because of the possibility of transmitting HIV infection (Polywka et al., 2005). Many countries employ stringent blood donor selection criteria to defer potentially infectious donors with high risk of HIV infection and employ highly sensitive screening methods like Nucleic Acid Amplification Testing (NAAT) in a nationally coordinated Blood Transfusion Service. Following this approach, developed countries like the United States of America (USA), United Kingdom (UK) and France have successfully reduced infections through their blood supplies and the window period from an average of 22 days based on antibody ELISA to 11days using NAAT (Busch et al., 2003). In Africa where about 5 to 10% of cases of HIV are reported to have been acquired through blood transfusion (WHO, 2002), the use of sensitive testing assays has persistently posed a daunting challenge for most nations.
In Nigeria, the national prevalence of HIV among blood donors was reported to be 4.4% (PEPFAR, 2006) though, different researchers (Irene, 2002; Durosinmi et al., 2003; Imoru et al., 2003; Ejele et al., 2005) have reported varying prevalence from different parts of Nigeria depending on the setting, nature of blood donation, population prevalence, donor selection criteria and methods of assays employed in testing. Pre-transfusion screening of blood is aimed at reducing to the barest minimum the acquisition of transfusion transmissible infections like HIV through donated blood. Facilities for early detection of infection with newer technologies in asymptomatic carriers thereby narrowing the window period are not available in the study setting. Screening of blood donors rely on available antibody-based detection method for HIV infection. Local data from this centre on the percentage of post transfusion acquired HIV infection are lacking as far as the authors are aware.
1.2 Problem Statement
Detection of the early viraemic stage of HIV continues to be a challenge in transfusion medicine worldwide because of the possibility of transmitting HIV infection. Serelogical screening of donor blood for HIV antibodies remains a critical component of identifying and eliminating HIV infected blood donations but this test rarely detect HIV antigen positive blood donors who are in the window period. Hence there is need to assess the prevalence of HIV/AIDS among intending donors.