A changing donor landscape revealed by 12.5 years of residual risk estimates of TTIs using the NAT-yield/window period model with public health cost rationale for scale-up in India.

BACKGROUND AND

OBJECTIVES

Despite mandatory serological screening, transfusion safety in India is challenged by the ongoing burden of HBV, HCV, and HIV. This 12.5-year study assessed Nucleic Acid Test (NAT) performance, estimating yield, residual risk (RR), and cost-effectiveness, with a focus on repeat blood donors (RBDs).

MATERIALS AND

METHODS

This retrospective study (Jan 2013-June 2025) was conducted at a tertiary care blood centre in a metropolitan city (North India). A total of 142,710 seronegative whole-blood units were screened using Cobas TaqScreen MPX v1.0/2.0 (MP6), with serology performed on CMIA. NAT-only reactivity used to estimate incidence and RR using virus-specific window period models. Post-donation counselling was used to assess risk disclosure, while cost modelling evaluated NAT implementation against the treatment burden.

RESULTS

Fifty-seven NAT-only reactive cases were identified (NAT yield: 1 in 2504), comprising 49 HBV, 7 HCV and 1 HIV. NAT reduced RR to 109.41(HBV), 4.18(HCV) and 4.97(HIV) per million donations (>90% risk reduction). RBDs comprised comparable proportions of NAT-yields. Among the 44 donors (77.19%) who returned for post-donation counselling, 30(68.18%) disclosed high-risk behavior out of which 28(93.33%) donors were RBDs. Cost analysis showed NAT implementation though costed ₹17.1 Cr (USD 2.06 million), could prevent an adjusted burden of ₹66.39 Cr (USD 8.0 million), yielding net savings of ₹49.29 Cr (USD 5.94 million).

CONCLUSION

NAT markedly reduces RR and detects previously unreported risks, particularly among RBDs. Its implementation is both clinically and economically justified, supporting nationwide NAT scale-up and a transition to universal NAT implementation in India.