Significance of Adopting Nucleic Acid Amplification Technique for Blood Donor Screening in a Resource Limited Setting: A Study from a Single Centre in South India.

ABSTRACT

Nucleic acid Amplification testing (NAT) has helped improve blood safety and detect window period and Occult Hepatitis B infections (OBI) This study was aimed at determining the following in blood donors 1. seroprevalence of HIV, HBV & HCV, malarial parasite and Syphlis 2. NAT and seroyield for HIV, HBV and HCV 3. viral load in NAT yield donations 4. Pattern of HBV serological markers in HBV NAT yield donations 80,809 blood donations were screened over an 8 year period (2012-2019) for antiHIV I and II, HBsAg, antiHCV antibodies, malarial parasite and VDRL. Seronegative samples were tested by NAT using a multiplex PCR in a pool of six. NAT yield samples were tested for viral load and HBV serological markers. Seropositive samples were tested for NAT and checked for seroyield. SPSS windows version 24.0 was used for statistical analysis. 1.07% of blood donors were found to be seropositive with 0.08%, 0.86%, 0.09%, 0.03% and 0 for anti HIV I and II, HBsAg, antiHCV, VDRL and Malarial parasite respectively. Out of 79,938 seronegative samples, 20 samples (0.025%) were NAT positive for Hepatitis B with a NAT yield OF 13997. Out of the 20 NAT positive samples, 17 were OBI and three were window period infections. 14 NAT yield samples subjected to a HBV viral load assay showed a range of < 6-146 IU/ml. Minipool NAT in pools of six is able to indentify both OBI and window period infections. NAT could significantly improve the blood safety in a resource limited setting like India.