Up to 100 people who had coronavirus were told they were negative after receiving the wrong test results.
The HSE has confirmed that the people were initially told they did not have the virus due to indeterminate results from lab tests. It was not possible to retest in the required timeframe, the HSE said.
A statement from the HSE said: “The HSE identified that, on Saturday 11 of April, less than 100 people had been advised, in error, that their test did not detect Covid-19.
“On review these patients were, in fact, positive for Covid-19.”
Reviews by the National Virus Reference Laboratory showed that some samples tested as “weakly positive.”
“Unfortunately, these indeterminate cases were initially reported as not detected and consequently were notified to people as such in line with the results communication process.
The error was picked up by the HSE’s Contact Tracing Team and remedial action taken immediately.
“We are satisfied that no other patient has been impacted by this error,” said the HSE statement.
“The HSE apologises for this error, and every effort has been made to ensure that the correct information is communicated to these patients without delay.”