Introduction: Transfusion transmitted infections (TTI) are major risk factors for blood transfusion. To increase the blood safety IDNAT has been introduced along with compulsory donor screening tests in all NACO assisted blood banks by Government of Karnataka and KSAPS from Dec. 2011. To evaluate the safety benefits of introducing IDNAT and to estimate the seroprevalence of infectious markers TTI and their yearly trends among blood donors, a retrospective studywas conducted at Blood bank of Hassan Institute of Medical sciences, Hassan, Karnataka. Materials and Methods: Blood bank records were reviewed retrospectively from January 2013 to December 2016. Results of mandatory serological tests and NAT Yield cases were compared. Descriptive statistics were used to estimate the prevalence of TTI and to show their yearly trends for four consecutive years. Result: Total numbers of blood units collected during study period were 18,694. Voluntary donors were 69% and Replacement donors were 31%. Out of 176 infective cases detected 23 were serologically non reactive but NAT reactive giving a high NAT yield of 1 in 812 cases.Overall prevalence of TTI was 0.94% and seroprevalence of HIV (0.08% ), HBV ( 0.80%), HCV (0.06% ), Syphilis (0.01% ). An increasing trend of HBV infection and decreasing trend of HIV, HCV were observed among blood donors in these four consecutive years. Conclusion: The present study population showedcomparatively low prevalence of Transfusion transmitted infection and it clearly indicated the benefits of IDNAT screening for the improvement of blood safety.

Keywords: IDNAT; Blood Safety; Blood Transfusion.