Backwards contact tracing of those who test positive for Covid-19 will be extended from two to seven days from next week.
The extension of contact tracing will only be offered to those who are infected through community transmission, where the source of transmission is unknown, which is in about 20 per cent of all cases.
It is part of the "end-game strategy" along with the vaccine to eliminate Covid-19 from Irish society, according to the Health Service Executive's head of contact tracing Greg Martin.
He said moving from two days to seven will identify more cases. As the vaccination rollout continues and numbers fall, “we will have a mechanism now where we can aggressively chase down every last case”.
It will also provide greater information as to how the virus is spreading in communities.
“As restrictions are lifted that becomes increasingly important so that we have an evidence base to make public health advice and recommendations,” said Dr Martin.
Those who test positive will be asked who they were in close contact with over the previous seven days. Their close contacts will not be asked to self-isolate or restrict their movements, but will be invited to take a Covid-19 test.
He said seven days was the threshold that will give greatest “bang for the buck” in terms of the resources needed to track and trace.
There are 850 contact tracers and this is sufficient for the number of cases that are around at present. They have made a million contact tracing calls to date.
He said it will be data driven as to whether the process is turned on or off because widespread community transmission, as arose after Christmas, makes contact tracing very difficult.
Infections spike
Extended periods of contact tracing have been called for since the beginning of the pandemic.
It was introduced on a trial basis in early December when numbers were at 200 a day, but abandoned when infections started to spike during the third wave.
When asked why it had not been introduced earlier, Dr Martin said he was not involved in the decision-making around it.
“Whatever intervention that you introduce in a pandemic like this, it is probably always the case that you should have done that sooner,” he said.
“At every point in the pandemic, the HSE is responding with the resources that it has. Of course we would have liked to see everything that we have done to have done it sooner, but we were doing something else.”
Dr Martin said the UK variant of the Covid-19 virus has had a much greater impact on transmission than previous variants and that the same socialising this year yielded a much greater level of cases.
He said it was “almost like a different battlefield”.
