Seven Years Experience in NAT Testing of Blood Donors in a Tertiary Care Centre

Abstract

Introduction: Nucleic acid amplification testing (NAT) is a very sensitive and specific test for viral nucleic acids.It reduces the window period for detection of viruses. It is highly beneficial in countries like India which has a high incidence and prevelance of transfusion transmitted infections. NAT is expected to identify many NAT yield cases which are not detected by other serological tests. Material and methods: A retrospective analysis of transfusion transmitted infection (TTI) reactive units in a tertiary care hospital was done over a period of seven years from Jan 2011 to Dec 2018. The blood units were tested by enhanced chemiluminesense technology and Individual donor nucleic acid testing (ID-NAT). NAT yield was calculated for Hepatitis B, C and HIV. Results: Out of 23,378 collected blood units, 380 units (1.62%) were found to be reactive for one or more transfusion transmitted viruses by chemilumunisense and/or NAT. 371 units (1.58%) were found reactive by chemiluminesense and 190 units (0.81%) by NAT. All the NAT yield cases were for hepatitis B virus and it was 9 (1:2597). Conclusion: NAT is more sensitive than chemiluminisense in detection of Hepatitis B. It detects both window period and occult infection.It has made a significant contribution towards ensuring safe blood transfusion by helping in reduction of window period transmission of Hepatitis B. It is important to implement NAT in developing countries like India to enhance transfusion safety.