The Health Information and Quality Authority (HIQA) has published advice it gave to NPHET on the coronavirus pandemic in relation to testing and restrictions.
It says the current 14-day period of restriction of movements for close contacts of a COVID-19 case should remain in place.
The National Public Health Expert Team had asked HIQA to examine if the current evidence supported a 14-day isolation.
HIQA said it examined the available evidence on the incubation period - which is the time from exposure to symptom onset of COVID-19.
They concluded that in the absence of testing, a 14-day period of restriction of movements is "likely to capture 95% of individuals who will become symptomatic."
Dr Máirín Ryan is HIQA's deputy chief executive: "Without changes to the current testing strategy, we advised NPHET that the 14-day period of restriction of movements should remain.
"It is essential that people who are exposed or potentially exposed to COVID-19 restrict their movements to minimise community transmission as it has been shown that people with no symptoms can spread the infection."
NPHET also asked HIQA to explore the potential impact of testing to reduce the period of restricted movements for close contacts.
But HIQA's advice said that any reduction presented "an increased risk of transmission."
However Dr Ryan added: "If, at a later stage in the response, changes are made to the current testing strategy for those restricting movements, these changes need to come with a clear communication strategy.
"It is important that people understand the reasons for the two tests and the implications of receiving a 'not detected' first test result, as many people at this early stage may still be in the incubation phase of the disease.
"Irrespective of any changes, it is vital that people continue to adhere to all COVID-19 public health guidance."
