Between 10,000 and 15,000 people who may have been exposed to Covid-19 were not informed due to the latest HSE fiasco which caused its contact tracing service to be swamped.
This increased the chances of people who caught the virus unknowingly passing it on to others.
A proportion of these people who were in contact with a confirmed case may be in danger of developing symptoms themselves and also of unwittingly spreading the disease.
The latest scandal followed an admission by the HSE that between 2,000 to 2,500 people who tested positive at the weekend could not have their close contacts traced because public health departments were swamped.
Instead, they yesterday appealed to people who tested positive to personally alert their close contacts and advise them to seek a test through their GP.
A leading GP said last night he believed a proportion of these people are still unaware they are at risk.
Dr Denis McCauley, spokesman for the Irish Medical Organisation (IMO) said he did not believe all of those who tested positive for the virus on Friday, Saturday and Sunday listened to the HSE when they were asked to inform their close contacts. He said the move by the HSE would have mitigated the risk of the virus spreading, but it would not have eliminated the chance that people who have the virus are still not aware they pose a danger of developing symptoms or passing it on.
"A decision was made by the National Health Protection Team (Nphet) that only one test was needed among this cohort," Dr McCauley said.
He said the outcome would not be as good as it would be if contact tracers in the HSE made contact with all of those people and that there would be a percentage of people who would be missed and in danger of spreading the virus.
"There are more than there should be if the system was perfect but there are less than if they asked us to do this hybrid method," he added.
The HSE said the decision to ask people who tested positive to personally alert their close contacts was a "one-off temporary measure" in response to an unprecedented rise in positive cases confirmed across the country.
"Over the past six months, we have rapidly built a robust testing and tracing capacity to meet Irish demand," a spokeswoman said.
"We increased our laboratory testing capacity both on and off island. We implemented major process and technology changes on how we do our testing and tracing, deployed our Covid Tracker App and automated major elements of the process.
"A significant recruitment campaign for testing and tracing, requiring engagement and negotiations with trade unions and role profiles, was initiated.
"Some 600 new contact tracers are through the interview process.
"We plan to recruit up to an initial 800 contact tracers, and then review the requirement for further recruitment. At present, we are increasing our contact training staff by 70 per week.
"All staff are provided with comprehensive contact tracing training. Our contact tracing centres currently have 500 resources," she added.
"More than 130 new community swabbers are in place, with a further 226 new community swabbers starting imminently.
"The appointment of new staff will continue through November to meet staffing requirements."
There were three additional deaths and 1,167 new cases reported yesterday.
Some 263 of the cases were in Dublin, 142 in Meath, 137 in Cork and 86 in Cavan, which remains the county with the worst fourteen day incidence.
"We are facing into a big challenge but we have faced it before," Chief medical officer Dr Tony Holohan said.
As the country begins a second national lockdown today, gardaí will be out in force staging hundreds of rolling checkpoints to ensure people stay within 5km of their homes. These are in addition to the more than 130 static checkpoints on the country's motorways.
Evictions will be banned for more than seven weeks from this Saturday under new legislation agreed by Cabinet.
The ban will be in place for the next six weeks plus an additional 10 days. The legislation means the eviction moratorium automatically kicks in any time the Government introduces a 5km travel ban.