Public health doctors are increasingly trying to hunt down Covid-19 in hidden places across the country.
New figures yesterday revealed the source of a large number of new cases of the virus could not be found.
These cases of community transmission amount to some of the biggest threats to handling the pandemic.
As many as 21 of the newly diagnosed 79 people diagnosed with the virus could not say where they picked it up, signalling it is spreading in the community.
Earlier this week it emerged this level of community transmission of coronavirus in Ireland had doubled in the previous 10 days.
Yesterday's figure also revealed that the virus is continuing to spread across a wide swathe of the country.
It emerged that 43 of the new cases were diagnosed in Dublin and nine in Kildare, which remains in semi-lockdown.
Another 12 people were diagnosed in Cork and Tipperary while the remaining 15 cases were in Clare, Donegal, Laois, Limerick, Louth, Mayo, Roscommon, Wexford and Wicklow. The majority are aged under 45.
Around 30 cases are associated with known outbreaks of the virus, such as workplaces.
But yesterday it was confirmed a 23-year-old female inmate has become the first prisoner in the prison system to be diagnosed with the coronavirus.
The positive test was confirmed at the Dóchas Centre facility for women in Dublin.
The homeless woman was remanded in custody earlier this week by a district court judge in relation to an offence of threatening and abusive behaviour.
Like all prisoners who go into the jail system, she was required to self-isolate for 14 days and was tested for the virus.
"She was asymptomatic but was still put in mandatory quarantine and yesterday the test results came back as positive," a source explained.
Sources say it is "truly amazing" and an issue of "first class governance" that it has taken until now that there has been a Covid case in the prison population.
Meanwhile one of the key messages to the public this weekend is to limit social contacts because it is people who spread the virus.
Acting chief medical officer Dr Ronan Glynn said: "We as a nation must show solidarity with Kildare in our collective efforts, especially over the next two weeks, by working together to suppress this virus.
"We can protect each other by following the public health advice.
"I am asking all households across Ireland to play your part, reduce your social contacts, wash your hands, keep a two-metre distance from each other and wear a face covering in shops and on public transport.
"These actions are vital to protect our families and safeguard those who are most vulnerable to the disease."
Taoiseach Micheál Martin said an advanced payment had been approved to ensure the country receives a share of any successful vaccine that might emerge from ongoing trials.
The World Health Organisation (WHO) said yesterday it hoped the coronavirus crisis will be over in less than two years.
The international public health body also recommended that children over 12 wear masks in the same contexts as adults in the bid to curb the spread of the virus.
"Children aged 12 and over should wear a mask under the same conditions as adults, in particular when they cannot guarantee at least a one-metre distance from others and there is widespread transmission in the area," the WHO advised.
Visit our Covid-19 vaccine dashboard for updates on the roll out of the vaccination program and the rate of Coronavirus cases Ireland