IBTS confirms a transfusion transmission of Hepatitis B (HBV)
Wednesday 30th August 2017
The IBTS today (Wednesday) confirmed that there has been a case of transfusion transmitted infection of Hepatitis B. This does not represent a test failure but represents a donation made in the window period when the presence of the virus cannot be consistently detected even by the most sensitive tests available.
An investigation carried out by Grifols/Hologic, the manufacturer of the assay used to test for hepatitis B virus (HBV), confirmed the assay performed to the expected standard of sensitivity for the detection of HBV. (i.e. this was not due to a test/assay failure).
“The IBTS wishes to stress that this is a rare one in two million event - and does not have any implications for blood that will be transfused to patients in the future. The IBTS has tested 1.2m donations to date and there has been no other confirmed transfusion transmitted infection of Hepatitis B.” said Dr Stephen Field, Medical and Scientific Director.
A blood donation was taken and the red cells were transfused to a patient, as a standard medical procedure. At the time the donation was tested, using one of the most sensitive molecular screening assay available internationally (Nucleic Acid Testing) in individual donation format. The donation was shown to be negative for viral markers, including Hepatitis B.
Subsequently the donor was found to have acute Hepatitis B infection and the IBTS was informed by the Public Health authorities immediately the donor presented with this condition. The archived sample of the donation again tested negative on the ID NAT screening test as before. However, an additional discriminatory test for HBV virus DNA was positive when tested.
The IBTS contacted the patient’s clinician who was informed of the test result. The patient was recalled for testing and was found positive for HBV. The patient is being managed appropriately by a medical team.
Note to editor
Hepatitis B virus (HBV) is a common infection of the liver, causing millions of infections worldwide every year. The virus is transmitted through exposure to HBV infected blood and body fluids (e.g. semen, vaginal secretions). The most common routes of transmission relate to close contact (e.g. sexual, mother to child, household) with an infected individual, sharing of needles for injecting drug use, or exposure to HBV in the setting of healthcare.
Transmission of HBV by transfusion is now rarely encountered with highly accurate/sensitive laboratory testing of every blood donation -see above. Overall, there is a low prevalence of HBV in Ireland compared to many countries and blood donors are amongst those with the lowest prevalence of HBV infection.