When a house party blew in and out of Kerry two weekends ago, hangovers were not the only unpleasant aftermath. It has left quite the mark on the local community. The group consisted of up to 30 friends, who travelled from various counties, including Dublin, to stay in rented accommodation. Most travelled by car but one of them came by public transport.
Mercifully they didn't go to the local pubs for food and a pint, public health officials were later told. Instead, they partied in their rented pad. According to Dr Gary Stack, a local GP, the weekend was in full swing when one of the party-goers received the dreaded message from contact tracers: you have been in contact with a confirmed case. That didn't seem to stop the party.
The group broke up, party-goers returned to their home counties after the weekend, and a small number of them - including some Kerry locals who had been at the party - decided to go for a Covid-19 test. Dr Gary Stack said that in the two weeks since, three local people have tested positive for the virus and all three cases have been traced to that house party. The last Covid-19 case in the county before then was in April.
Dr Stack said it will be another week or so before the contacts of those three new cases find out whether they are in the clear or not. So far, it is known that there are four down - including the source of the infection, who is from another county.
The extent of the fall-out from that single house party of 30 people is not yet known. As public health officials described it in a letter to local GPs, efforts to contain the cluster were now spread across several parts of the country. Public health sources say most of the group have been traced and referred for testing, as were their close contacts - and on it goes.
The Kerry house party can't be blamed for the surge of Covid-19 cases recorded in recent days and observed with alarm by public health experts. But it is almost certainly a factor and a lesson in the potential of the virus to mushroom from one location to multiple sites across the country.
Two weeks out from the reopening of restaurants, coffee shops and hairdressing salons, cases of Covid-19 are on a worrying upward trajectory.
GPs first noticed the increase in cases on Monday, July 7, according to a web platform that allows GPs to track community health issues, GPbuddy. The referrals and requests for tests have climbed steadily since, said Dr Darach O Ciardha, one of its co-founders. More than 90pc of cases were acquired in the community, rather than from travel, or hospitals or nursing homes.
In Monaghan, GP Illona Duffy said that although her own practice has not had a confirmed case in three weeks, the virus is still circulating. She is aware of two staff members at a nursing home who recently became infected, although the residents are safe.
"When the virus is in a cluster, you can track it within a group. When it's just out there, sporadic, it is harder to contain," she said.
At his Ranelagh clinic on Friday morning, GP Maitiu O Tuathail spent the morning referring around a dozen patients with flu-like symptoms for Covid-19 tests - levels he has not seen since March. They were all under 40 and "quite open" about being out socialising, he said.
"There is fear that people are not coming forward for testing because of the stigma/shame that people will say you were not following the rules - which is just not true," he said. "You can follow the rules and still get Covid-19."
On Friday evening, the National Public Health Emergency Team recorded the highest spike in new cases in months: 34 new cases of Covid-19. Yesterday, 21 more cases were recorded, bringing the total to 25,750.
An increase in cases was always inevitable as restaurants and pubs serving meals open, people are able to travel, and holidays - even if they are staycations - became possible again. But not at this level. The sharp rise during the past two weeks has alarmed public health officials and the country is on a Covid-19 knife-edge.
Ireland has one of the lowest prevalences of Covid-19 in Europe but the incidence is rising. The reproductive rate of the coronavirus, the R number, in Ireland is now between 1.2 and 1.8 when the aim was to keep it below one.
Dr Ronan Glynn, the acting chief medical officer and chair of the National Public Health Emergency Team (Nphet), said it was time to redouble efforts to suppress the virus. We live in "uncertain" and "precarious times", he warned.
The Government has stalled the reopening of all pubs until August 10 and face masks are finally being introduced in shops and businesses.
The tourism industry is a mess and embroiled in more mixed-messaging. Public health experts say don't travel if you don't need to.
The Government says if you must, then go, but you must quarantine unless you travel to one of the "green list" of countries it is due to publish tomorrow. But will many travel?
A public opinion survey for the Department of Health last week showed 78pc believe a second wave of Covid-19 is coming.
With Ireland on the cusp of a second wave, how much do we know about who is getting the virus and how it is spreading?
Nphet has rolled out the daily toll of the coronavirus in Ireland every single day since the first case in February 29. But are we any closer to understanding the journey that brought it here and how it travels from one person to the next across the country?
While contact tracing can link up cases that have passed from one individual to the other, a sizeable number of infections are classed as "unknowns", random one-offs that can't be traced to any particular source.
In recent weeks, the public narrative has been around young people and tourists. Clusters of the virus in private houses increased by 96 at the start of the month, many believed to be linked to house parties.
While Nphet warns against foreign travel, the government Covid data hub shows that cases related to travel abroad have been low to date, with just two cases recorded on Friday, compared with 52 at the outset of the pandemic on March 16.
An academic who drilled down into the figures said most of those contracting Covid-19 are not young people partying or people flying in from overseas. They are, in fact, health workers.
Mark Roe, a post-doctoral researcher at UCD School of Public Health, Physiotherapy and Sports Science, analysed Covid-19 cases over 37 days since phase two of lifting the pandemic restrictions began on June 8.
The total increase in cases over those 37 days was small, just 2pc in those aged between 15 and 54.
Given Nphet's concern about younger people contracting the virus, Roe took a closer look at the figures.
Yes, there was a 5pc increase in the numbers of Covid-19 cases in children and young people up to age 24. But the biggest increase by far - and the one least commented on - was in health workers.
"Young people had been away from their friends/peers for close to 100 days when phase two began, so with more interaction it's predictable to see cases pop up here. But there has been a total of 101 cases in these two age groups, and just four of them have ended up in hospital. Not one required ICU," he said.
"The most worrying statistic is that healthcare workers, accounting for 32pc of cases before phase two, have accounted for 48pc of all cases since."
Why are health workers still contracting the virus?
Some medical commentators believe that it is an "occupational hazard" simply because they are more exposed to it than most. Roe said it is important to find out.
"If anyone was to ask me what has changed since phase two, I'd say nothing … they still haven't figured out the basic pattern of who the disease is affecting most."
Other countries have been tracking the virus as it moves through societies, using a process called genomic sequencing. The process identifies mutations or changes in the sequence of the virus as it passes from human to human, which then allows scientists to investigate how it spreads, whether there is one or many sources of an outbreak and sometimes where it came from.
In Melbourne, Australia, where new cases spiked by 428 on Friday, genomic sequencing has been credited with mapping the city's second surge.
By examining the genetic make-up of the virus identified in individuals, the scientists could trace many disparate outbreaks.
The discovery has caused political headaches for the local government authorities. But from a public health point of view, it allowed officials to focus their energies on stamping out the infection at source, rather than fighting multiple infection battles across the city.
Now that first wave of Covid-19 has passed, Irish scientists have quietly embarked on some genetic detective work of their own and their work is gathering pace.
Professor Seamus Fanning, who heads the Centre of Food Safety at University College Dublin, is working with other researchers on a pilot project conducting genome sequencing on Covid-19 positive patients. "If you can understand how the virus transmits, then the infection control experts can respond, being armed with more detailed information that could be helpful to them."
Work is still in progress, so Prof Fanning is not able to share any findings. However, he confirmed researchers have identified distinct Irish strains of the virus.
"We can recognise clusters of Irish Covid-19 viruses when we compare them against a global database," he said. "There might not be one, there could be a number of Irish clusters sitting in among other global clusters. When you drill down further and look at that more locally, this information can be helpful by telling you how that virus is transmitting."
The finding is significant because it means that scientists may be able to detect whether outbreaks here stemmed from one source or were caused by different carriers, simply by analysing the genetic code of the virus.
The viral genome is made of thousands of bits of nucleic acid, or RNA. The RNA is decoded to reveal the protein structures that make up the virus and scientists look for differences in the RNA sequence across the genome. These differences, said Prof Fanning, can help to track the virus, giving a broad picture of where it came from and may have spread from one person to another.
As the virus hops from one human to the next, it changes slightly or mutates with each move. But the more similarities the sequencing reveals, the more likely the samples of the virus originated from the same source.
As the virus travels further afield, more differences in the sequence will emerge.
Heading UCD's Centre for Food Safety, Prof Fanning ordinarily uses genetic sequencing to track bacteria of importance to public health from food-producing animals to the food chain to humans, where they may cause serious infections, and to predict the bacteria's behaviour.
"We are trying to use the same approach here so that we can start to develop a picture that might be of help to people on Nphet and those involved in infection control," said Prof Fanning. "What we are trying to do here is put our skill set to work in the national interest."
The need for genomic sequencing of the virus becomes even more urgent given health officials concerns that imported cases from tourists or returning holiday-makers could trigger a second wave.
It can help tell public health officials if indeed the virus was imported, from which country and potentially the specific holiday resort location.
Early genomic testing on a small number of samples by the National Virus Reference Laboratory showed that most of the cases came in from the European Union.
Meanwhile, an Irish academic in Nottingham, Prof James McInerney, found similarities in the virus in Irish laboratories and tested in labs in Birmingham, Boston and Copenhagen.
The Birmingham connection led to speculation that Cheltenham could have been a source of one of the Irish strains.
Dr O Tuathail, who treated only last week at a Covid-19 testing hub two visitors to the country who tested positive, said: "I personally think that the fact that people are allowed to enter the country without restriction is madness."
According to one of the infectious disease consultants who has been at the front line of the coronavirus battle, community transmission remains the key source of infection in Ireland.
"This is not Americans coming in from Texas with Covid-19 - the problem is Covid-19 is circulating in the community and that is 88pc of the problem," said Dr Jack Lambert, a consultant at the Mater hospital in Dublin.
"I think we need to have a balanced view on this and understand where our priorities are. If you have a crack in the dam and there's a little one downstream, are you going to fix the one downstream and let the big one break?
"The big problem is still Ireland and the young adults that are spreading the virus. How do we tackle that? The police won't work, so we have to think about how we can address that.
"That is the issue we need to focus on."
Life will never be quite the same for any of us after 2020. When Boris Johnson appointed me Secretary of State for Northern Ireland in February, I was honoured to be given a chance to take forward the huge advances which have been made in Northern Ireland.
We're now almost seven months into the Covid-19 crisis. And time keeps dragging on. Early on, the world turned to experts to explain what was going on. Politicians brought them in to advise on what to do. Terms like 'epidemiology', 'R number' and 'cytokine' now trip off many people's tongues. And everybody now knows the name of an immunologist: Tony Fauci.
The respected Belfast-based physiotherapist Shea McAleer tweeted last week: "Does anyone know where I can enroll on a cure/faith healer course? This is quite popular currently among GAA club managers. A client with a G2 ankle syndesmosis went for 'a cure of the sprain' with a healer which didn't end well. 'Cure of the hamstring' seems popular too."