The coronavirus test, trace and protect system in Northern Ireland is "failing", the chairman of Stormont's health committee said.
In a recent week in November, 94% of close contacts of cases were traced, Health Minister Robin Swann said.
Colm Gildernew called for an overhaul of the system.
Sinn Féin's health committee chairman said: "What we need to do is increase our test and tracing capacity and we need to recruit more contact tracers at a quicker level.
"Will the minister commit to a new strategy to replace the failing test, trace and protect system?"
The minister responded to questions at the Assembly as well as the suggestion the health service was working at 106% of capacity.
He said: "Even with high numbers coming into our test, trace and protect system they were achieving high levels."
He said the system needed support from people following the public health advice.
"Test, trace and protect works best when you have a low number of cases.
"That needs to be our strategy, not how we increase test, trace and protect but how we reduce the people with Covid in our community."
He listed a series of measures put in place ahead of the second wave, including creation of a step down facility for those recovering at Whiteabbey in Co Antrim which is due to open soon.
"What I can never have planned was for the scientific and medical advice given to the Executive being blocked, because only when the spread of the virus is minimised can we hope to reduce the Covid-19 pressures on our health service and that is what is really needed and it is needed now."
He said non-Covid outpatient activity was 73% greater in October than during the first wave of infection in April.
Mr Swann said: "That is because of our surge and rebuild plans.
"That is the truth of the matter, it is testament to the dedication of our health and social care staff."
Deputy First Minister Michelle O'Neill also raised concerns about the level of planning done by the Department of Health for the second surge.
"The message the public needs to hear, even from this chamber this week, is that we are working together, that we're going to try and chart our way through this so that we can get to the other side of this," she said.
"The best way we do that is with the most first-class find, test, trace and isolate system in place.
"I don't think enough was done in terms of the Department of Health preparation for where we are now. We always knew winter was coming, that was a certain.
"We didn't know when the second wave would come and I think it came quicker than people actually expected."
