The manufacturers of the blood-testing kit currently at the centre of an alert over babies in Ireland potentially being given the wrong blood group at birth issued a warning about possible problems with the kit back in June, it has emerged.

A UK safety agency posted an alert on its website about the incorrectly labelled blood kit in the first week of July.

However, the public here was only informed by the HSE about the blood test kit issue today, nearly two months after the alert from the company, and the Irish hospitals involved only started contacting affected mothers last Monday.

The HSE has moved to reassure anxious parents after it emerged that a number of mothers and babies have been told by hospitals that there may be a small chance the baby has been given the wrong blood group at birth as a result of a batch of around 540 mislabelled kits being issued.

There is a chance too that some of the mothers and babies may have been given treatments they did not need or else did not receive treatments they needed as a result of the mislabelling. The HSE says there are no immediate safety concerns and that the chances of babies being assigned a wrong blood group are extremely low.

However, the manufacturers of the Ortho BioVue System Cassettes kit, Ortho Clinical Diagnostics, a subsidiary of Johnson & Johnson, issued an alert in a letter to customers from its European office on June 25 informing them that it had identified 'isolated occurrences' of improperly positioned cassette labels on some of these kits.

Customers, which would mostly include hospitals and health authorities, were told that they may have been shipped some potentially affected products.

The alert states that the occurrence rate of the issue is very low. It warns, however, that the use of an affected multi-reagent cassette may lead to false negative or false positive results, causing a potential misclassification of the patient or donor blood groups, or incorrect antibody detection results.

Those using the kit were asked to inspect all cassettes from the potentially affected lots remaining in their facility prior to use, and were told not to use cassettes with an incorrectly positioned label.

It is not clear at this stage when hospitals in Ireland would have been informed of the incorrectly labelled cassettes, nor when the regulatory authority here, the Irish Medicines Board (IMB) or the HSE first became aware of the issue.

The HSE said today it was 'recently' informed by the IMB that a field safety notice had been issued on the blood testing kits involved.

It said the a small number of the testing kits supplied worldwide had been incorrectly labelled.

The alert from the manufacturers was posted in a list of safety notices on the website of the UK medical devices safety agency, the MHRA, in the first week of July.

However, there is currently no safety notice on the Ortho BioVue product on the IMB's website.

Alert over blood test mix-up.