The Health Service Executive has said that around 25 to 30 repeat PCR tests are conducted each month, after issues arise with the first test.
It said that repeating a PCR test and interpretation of the result can take into account the person's clinical history, their clinical condition and the reason for the first test.
The HSE said it may also take account of whether or not they were a close contact, if they had a previous positive test result and "various parameters within the test process itself." The HSE said that as a patient's test result can be reviewed by a GP and public health at a local level, the HSE Test and Trace programme will not necessarily be made aware of all individual patient cases where a repeat test is ordered.