Written Answers. - Hepatitis C Testing.

Noel O'Flynn


98 Mr. O'Flynn asked the Minister for Health and Children the average and longest delays in the Blood Transfusion Service Board receiving donor HCV (hepatitis C) PCR testing results from Edinburgh; and whether blood or blood components have been released for patient usage without HCV PCR clearance since this testing was introduced. [10269/00]

Current serological tests for hepatitis C are extremely robust and sensitive and are applied in respect of the release of all components at the BTSB. In addition, PCR testing is a further safeguard aimed at detecting hepatitis C during the window period between infection and the production of antibodies which are detected by the standard serological tests. The typical length of the window period without PCR testing is ten-14 weeks. Following introduction of PCR testing, this window period is reduced to approximately two weeks. To date, no donation has tested positive for hepatitis C by the PCR test.

The introduction of PCR testing for hepatitis C is being applied internationally in response to the European committee for proprietary medicinal products (CPMP) requirement that all manufactured blood products released for use within the EU must be derived from plasma pools that have tested negative for hepatitis C by a validated PCR test. This requirement arose from the transmission of hepatitis C associated with HCV screened intravenous immunoglobulin products which involved plasma pools from numerous donors. PCR testing for other blood components is not mandatory. However, in order to further improve safety, PCR testing for the hepatitis C virus is currently performed on all blood donations collected by the Blood Transfusion Service Board. In November 1999, the BTSB entered a contract with the Scottish National Blood Transfusion Service (SNBTS) to carry out PCR testing on its behalf and all donations after that date have been tested.

PCR testing for blood components for individual patients e.g. plasma, red cells and platelets is being developed internationally on a phased basis. The use of PCR results as a release criteria for blood and blood products by the BTSB is being phased in as follows. At the present time, the majority of PCR test results are returned to the BTSB on the fourth day after the donation has been taken. The assay test format being used requires two to three working days in the laboratory after donation. A small number of samples require further analysis because of difficulties associated with this test. The test results are currently faxed to the BTSB. Electronic exchange of data when the BTSB's new computer system is implemented will improve turnaround time in transmission of results. In the case of platelets, which have a shelf life of five days, improvement in assay and turnaround times will be required before PCR test results can be used to determine release of these products. The BTSB and the SNBTS are committed to implementing PCR testing as one of the criteria for release of red cells later this year. From next month, PCR results will be used as one of the release criteria for fresh frozen plasma.
Approximately 160,000 donations are tested annually by the BTSB. Donations found positive in serological tests are discarded and not issued. In the unlikely event that a PCR positive result is observed, e.g. a window period donation, appropriate follow up, including product recall, will be initiated. The risk of transmission of hepatitis C in the window period is currently estimated as one in 500,000. As already stated, no such reactive result has been observed to date.
The Irish Medicines Board, which is the regulatory authority, is satisfied with the current position regarding the implementation of PCR testing by the BTSB. All mandatory tests are performed on all components before issue by the BTSB. The BTSB plan to perform PCR testing at its own laboratory at the National Blood Centre. It will be at least a year before the testing system is validated and becomes fully operational.