The Irish Blood Transfusion Service Board has said the case is not due to a test failure, in a statement to media today. In the statement, they confirmed the case of transfusion transmitted infection of Hepatitis B. They wrote;
“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, and therefore the result is not due to a test 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,” said Dr Stephen Field, Medical and Scientific Director. “The IBTS has tested 1.2m donations to date and there has been no other confirmed transfusion transmitted infection of Hepatitis B.”
In the case, 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. The donation was shown to be negative for viral markers, including Hepatitis B. Subsequently the donor was found to have acute Hepatitis B infection. The IBTS was informed by the Public Health authorities immediately as the donor presented with this condition.
The statement continued;
“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.”
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). Most adults & individuals with normal immune systems will clear HBV infection.
However, those infected early in life or with immune deficits are more likely to develop chronic HBV infection.
Although treatment for HBV is available for those who become chronically infected; vaccination and screening is crucial in preventing onward spread.