From today contact tracing team will start  asking  additional questions to help identify the source of cases identified as community transmission. Currently, 80 per cent of cases of Covid-19 are traced to a specific source through the Health Service Executive’s contact tracing centres or through HSE public health teams. The remaining 20 per cent are classified as cases of community transmission. For the 20% of cases categorised as community transmission, additional questions will be asked about their movements over the previous seven days.

If a case has been categorised as community transmission, the person will be asked an additional set of questions. These questions will be based on the various events or settings they have been in over the previous seven days.

“There’s additional questions about when you were there, what was the date, what was the time and there’ll be questions about that setting. It’s actually a detailed set of questions that’s asked,” Dr Greg Martin HSE clinical lead for contact tracing said during a briefing today.This information will be passed on to public health departments and they will then decide whether the case requires a more detailed investigation.

“The purpose of that investigation will be to identify the source, so it might be that we actually find the original index case, but perhaps equally or more importantly we will identify other close contacts who were exposed at the same time,” Martin said.

These people will receive a text message offering them a test, but will not be required to restrict their movements while waiting for the results, Dr Martin said, because there is no firm information that this was necessarily the transmission setting. If they test positive, they will then be given the guidance on self-isolation.

Public health departments are already doing this kind of source investigation locally, particularly where there are larger outbreaks connected to particular locations or events. In some cases public health departments have been able to bring down the level of cases categorised as community transmission to 10% using this more detailed process. This will see the process become a more routine part of the contact tracing process to pick up more cases and to provide health officials with additional data on risks associated with certain settings. Chasing down every live case is going to be an important part of the endgame of our public heath response to this pandemic