The number of contacts of confirmed new cases of Covid-19 is "drifting upwards", an official disease modeller in Ireland warned.
The reproductive rate of the coronavirus remains below 1.
A third of contacts in a household subsequently tested positive, Professor Philip Nolan added.
The case number reduction is slowing down after weeks of lockdown, public health experts said.
The proportion of cases in highly-populated Dublin has increased as the more virulent UK variant dominates new infections.
The test positivity rate and hospital admissions is "plateauing", Professor Nolan added.
He said: "That is giving us some cause for concern."
The health service has been notified of a further 47 deaths related to Covid-19.
Another 901 cases were confirmed.
Professor Nolan said people had adhered to the public health guidance and case numbers have declined since the middle of January.
"We are maintaining suppression but it is precarious," he added.
The reproductive rate of the virus is at between .65 and .85.
The expert said: "There has been some drift upwards in contacts."
The modelled number of cases has been revised upwards for the coming weeks.
Professor Nolan urged: "Resist that tendency to mix more. It remains a dangerous thing to do.
"We have a fundamental concern that while we continue to suppress transmission, disease levels are still very high.
"We need to bring them down further. The rate of decline is slowing."
Deputy chief medical officer Dr Ronan Glynn said he did not want to see people returning to workplaces or increased household mixing.
He said: "It really is phenomenal to see the levels of compliance we have seen maintained since the end of the year.
"We continue to be enthused or gratified to see the response of the general public and their willingness to stick to it."
Professor Nolan said the number of deaths had finally started to ease off.
The authorities have recorded 35 newly-confirmed deaths per day over the last seven days.
Professor Nolan added: "We are coming towards the end of the wave of mortality."