Consecutive reactive results in screening of transfusion transmitted infections: Family history of blood donors is also important

Background: Enzyme linked immunosorbent assay (ELISA) test is used for screening of transfusion transmitted infections (TTI) in blood donors. Consecutive reactive results in ELISA is due to sample/reagent carryover or donor related. In this study we tried to find out the possibilities of family history/close contacts with patients of hepatitis among these consecutive reactive donors. Aim To analyze the consecutive reactive results in ELISA tests for TTI testing on samples of healthy blood donors. Material and methods: A retrospective observational study was conducted from January 2016 to July 2018 in a tertiary care hospital, North India. Consecutive reactive results by fourth generation ELISA for TTIs screening were evaluated for possible reasons. Confirmation tests were not done. Reactive donors were contacted telephonically for relevant history of close contact with infected personnel. Results: Out of 53,740 donations 1,061 were reactive for TTIs during our study period. Prevalence of Hepatitis B (HBV), Human Immunodeficiency (HIV) and Hepatitis C (HCV) virus infection in blood donors were 1.27%, 0.20% and 0.50% respectively. Consecutive reactive results for HBV were 9.20% (63/685), for HCV 6.0% (16/266) and nil for HIV. There was no sample carryover in this. Out of 79 consecutive reactive donors 69 donated for same patients and 32 were related with infected patient which are statistically significant (p < 0.0001). Discussion: This study recommends that in analysis of consecutive positive results in ELISA along with looking for procedure/sample error, there is also a need to take retrospective history of donors for close contact with infected patients.