The government has promised to step up testing for coronavirus in care homes where symptoms of the virus have been found.
But is it possible to get accurate figures about the scale of the problem?
How many deaths have there been in care homes?
This is difficult to calculate - there are more than 15,000 care homes in England, compared with about 200 hospitals.
Two of the UK's largest care home companies have provided the most up-to-date picture of what is happening in residential and nursing homes.
On Monday, HC-One, which operates 350 homes, said it had had 311 deaths linked to Covid-19, with outbreaks in two-thirds of its homes. The Methodist Homes Association reported 210 deaths in its 131 homes. Outbreaks occurred in about half of those homes.
There is a two-week time lag in the data collected for official statistics. The most recent figures from the Office for National Statistics are for the week ending 3 April. At that point, there had been 217 Covid-19-related deaths in care homes in England and Wales.
This means that about 5.3% of all COVID-19 deaths to that point had occurred in care homes - a high proportion, considering they house less than 1% of the country's population.
The time delay in these statistics has led some politicians to call for efforts to be made to provide daily figures, as with hospital deaths.
In Scotland, nearly a quarter of the 962 coronavirus deaths recorded up to 12 April were in care homes.
Northern Ireland's statistics body doesn't currently provide this breakdown.
England's care home regulator, the Care Quality Commission (CQC), already has to be notified when there is a death in a care home. From this week it will also ask care providers to give daily updates on deaths and the number of confirmed and suspected coronavirus cases.
How many people live in care homes?
Most care homes in the UK are privately run, and there is no official data on the exact number of residents.
The CQC says there are 15,517 residential and nursing homes providing support for older and disabled people in England, with an estimated 457,361 beds available.
Occupancy rates seem to be about 90% which would suggest there are about 411,000 people living in care homes in England and Wales.
At the 2011 census, 60% of the elderly care home population were 85 or older - but this is now likely to be higher, given the ageing population.
How many people receive care in their own homes?
Each week in the UK, it is estimated that 540,000 people receive support in their own home. That adds up to a million home-care visits happening each day.
What's provided on these visits can range from help going to the toilet, to preparing a meal or support with medication.
Care workers can at times see up to 20 clients during a day. This has raised concerns about the danger of spreading coronavirus if the workers do not have enough personal protective equipment (PPE).
How much PPE do social care staff have?
The government's advice to care homes on personal protective equipment (PPE) is almost identical to that given to hospital workers - they should have single-use disposable gloves, aprons and face masks.
Care providers have been saying for some weeks that it is difficult to get enough of these items to keep their staff and clients safe.
The government says it has already delivered seven million items of PPE, meaning every registered care home should have received 300 face masks each.
From 6 April, 34 million items of PPE have been scheduled to be distributed to care homes via local authorities (although some equipment is earmarked for other key services).
These items include eight million aprons, four million masks and 20 million pairs of gloves.
The government has also released £1.6bn of funding to local authorities - which are in charge of providing social care - with instructions that most of this should reach the adult social-care sector.
How many tests are being carried out in care homes?
There is no current breakdown, but the government has now announced that as laboratory capacity increases, all care home residents who develop symptoms will be tested.
So far, only the first five residents in a care home who show symptoms of coronavirus are tested to confirm whether there is an outbreak within a home.
Patients returning to care homes from hospitals will also be tested for Covid-19, even if they have no symptoms.
Are staff being tested?
Testing was made available to social-care staff just before Easter.
To date, the government has tested 1,000 care staff and is due to test a further 1,000 who are currently self-isolating.
The government has said as capacity increases it will roll this out so that every care worker who needs a test can get one.
The care sector has always struggled to recruit enough staff because of its reputation for low pay and a lack of recognition - it's estimated that there are currently 122,000 full-time equivalent vacancies in England.
Those problems have been made more acute with staff having to self-isolate if they or a member of their family have shown potential symptoms.
Some care providers have reported having at least a quarter of their staff off as a result.
The government says it aims to recruit 20,000 extra social care staff over the next three months.