Abstract
BACKGROUND: In Mexico, the detection of hepatitis B virus (HBV) in blood donors is achieved by screening for hepatitis B surface antigen (HBsAg). However there is still a residual risk of HBV transmission by blood components of donor suffering from occult HBV infection (OBI) or during the window period before seroconversion; in both the antigen expression can be undetectable. CLINICAL CASE: A 55 year old female donated whole blood in our blood bank,at health history and physical examination no health risk factors were detected. The whole blood was screened, the NAT assay was reactive therefore is screened by discriminatory assay for specific probes, resulting reactive for HBV. A second sample is tested for Hepatitis B serological markers, the sample was reactive for NAT HBV assay, anti-HB core IgG positive, non reactive HBsAg; these results reject a window period. Five months later a third sample was taken, NAT HBV and HBsAg test results were not reactive. We conclude this was a probable OBI infection or probable phase in clinical resolution for Hepatitis B case. CONCLUSION: This type of cases demonstrates the need and advantage the availability of sensitive and specific methods for the detection of viral genome or serological markers that increase blood safety for the recipients of whole blood, hematopoietic stem cells and tissues.