image captionHundreds queued around the leisure centre in Merthyr Tydfil to get tested in November
People queued around the side of a leisure centre to be mass-tested for Covid when Merthyr Tydfil was considered a hotspot in November, and the Army was drafted in to help.
UK Health Secretary Matt Hancock has credited this method of “lateral flow” testing for asymptomatic people with lowering case rates in Liverpool, another Covid hotspot.
He has since announced these regular rapid tests would be used in communities across England.
But are they likely to be rolled out across Wales?
What is a lateral flow test?
image captionThe lateral flow tests give a result within half an hour
It is a quick way of testing for coronavirus symptoms and returns a result in about 30 minutes.
This means those who have been in close contact with someone who has tested positive will not have to self-isolate if their test comes back negative.
Instead of having to self-isolate, they could remain at work or in the classroom if they tested negative with a lateral flow test each morning.
How effective are the tests?
image captionTest centres in the Lower Cynon Valley were open until 20 December
An article in the BMJ medical journal raised concerns about the effects of rapid testing in Liverpool, where a pilot scheme was carried out.
The lateral flow tests, which do not require processing in a laboratory, were reported to have missed half of all cases and a third of those with a high viral load who were likely to be the most infectious.
Angela Raffle, a consultant in public health at the University of Bristol medical school, also said increasing lateral flow testing was “very worrying” and warned the benefits of finding symptomless cases “will be outweighed by the many more infectious cases that are missed by these tests”.
However Susan Hopkins, chief medical adviser to NHS Test and Trace in England, said the lateral flow tests could identify many cases of infection in people without symptoms.
While she admitted there were “false” negatives” and the method had “limitations”, Dr Hopkins said its use was a “gamechanger”.
Where have they been piloted in Wales?
image captionCouncil and military personnel helped with a mass testing pilot in Merthyr Tydfil
Mass testing pilots were run in two Covid hotspots in Wales at the end of last year.
On the first day of testing in Merthyr Tydfil in November, 977 people were tested and nine of them were positive.
Mass testing followed in the Lower Cynon Valley in December.
Across both areas, a total of 1,100 positive Covid cases were identified after 50,000 lateral flow tests were carried out.
The Welsh Government also started a four-week pilot of routinely testing asymptomatic South Wales Police officers on 23 December.
Its aim was to reduce the numbers off work self-isolating, despite not being infected, following contact with a person who has tested positive.
While the trial is still ongoing, the Welsh Government said results so far showed a steady decline in Covid-related absences.
Regular testing of asymptomatic health and social care workers has also begun, and a pilot scheme is under way at the Tata Steel site in Port Talbot.
There were also plans to roll it out in schools and colleges across Wales in January, if they had opened as originally planned.
What is happening elsewhere?
image captionThe lateral flow testing method has been used widely during the pandemic
Lateral flow tests have been made available in all 317 of England’s local authority areas from this week as part of a community testing regime.
Councils have been encouraged to prioritise tests for those people who cannot work from home during the lockdown.
The Scottish government is also offering community testing in areas that have high prevalence of coronavirus.
What has the Welsh Government said?
image captionMass community testing has been trialled in Covid hotspot Merthyr Tydfil
A Welsh Government spokeswoman said officials were evaluating the results of pilots and initiatives, and looking at what was happening in other parts of the UK as it develops its approach to community testing.
However, a number of more targeted schemes are currently operating.
“We have announced regular asymptomatic testing of health and social care workers, in education and daily contact testing in South Wales Police,” the spokeswoman added.
“A pilot has also started at the Tata Port Talbot site.
“We are also exploring other opportunities for regular testing to support critical services.”
What have opposition parties said?
image captionRhondda Cynon Taf has had the highest number of Covid-19 deaths in Wales
The Welsh Conservatives have called for lateral flow testing to be “ramped up” in hospitals.
Health spokesman Andrew RT Davies said in December: “Hospitals are reporting high percentages of staff self-isolating, and therefore putting increasing strain on services and remaining staff.”
Plaid Cymru leader Adam Price has raised the need for “Covid Support Areas” - saying research from the north of England suggested post-industrial communities may be disproportionately affected by the virus.
In line with this, he called for mass testing as well as more financial support in areas such as Merthyr Tydfil, Blaenau Gwent and Rhondda Cynon Taf.