Details of how hundreds of patients have been infected with coronavirus while in hospital have been published for the first time in Wales.
Public Health Wales (PHW) is following counterparts in Scotland in publishing data of so-called nosocomial cases.
It found nearly 1,800 patients where it was "probable" or "definite" that they caught Covid-19 after being admitted.
PHW said 11% of all cases were due to hospital infection but numbers had dropped "considerably" since the peak.
How are patients with Covid-19 defined?
It can be complicated to be certain where patients caught the virus, particularly as some people are known not to show any symptoms.
Some patients may have been admitted to hospital unaware they already had it.
Infections are broken down like this:
- Patients who are given a positive test within two days of being admitted - this is still put down to an infection in the community.
- The second category - "indeterminate" - a positive test between three to seven days of being admitted to hospital
- "Probable" - the first positive test between eight and 14 days of hospital admission
- "Definite" - the patient has been in hospital for 15 or more days when they are first tested.
The PHW figures show 1,172 patients were in the "definite" category - and another 616 in the "probable" group.
There are just under 500 more in the "indeterminate" group.
In the latest week in Wales, ending 19 July, there were 125 confirmed Covid-19 cases.
Of those, 28 (22%) were hospital patients in the "definite" category, with another eight (6%) "probable", and six (5%) indeterminate.
The Aneurin Bevan health board's early deaths - when it was seen as Wales' hotspot - have been put down to hospital infections in a recent mortality review by Welsh scientific advisers.
The PHW figures show around 60 "probable" and "definite" cases from the area's hospitals in the week ending 22 March, just before lockdown was announced and there were still 50 in the week afterwards.
Robin Howe, PHW incident director, said real progress had been made and rates have "come down considerably" since the peak, by more than 90%.
"This data shows that the spread of coronavirus in healthcare settings is under control, and it is safe for people to access health services in Wales," he said.
"As in other parts of the world, hospital transmission has taken place in Wales, and the infectiousness of the virus has presented challenges for the health service.
"There were significant numbers of hospital acquired infections early on in the pandemic, with cases peaking in the week of 5 April."
'I didn't think for a minute that he wasn't going to come home'
Carolyn Evans's husband of 35 years, David, a retired maths teacher, died with Covid-19 in May. She is convinced the 61-year-old contracted it in hospital after being admitted, initially for three days, following an infection in his back.
After returning home and receiving treatment, Mr Evans, from Pontypridd, developed sepsis and was readmitted to the Royal Glamorgan Hospital. He developed viral pneumonia and later tested positive for Covid-19 while he was in intensive care.
"They did everything they could but I had a phone call on the day he died that he's had a clot and a bleed on the brain and the images weren't good," said Mrs Evans.
"A couple of hours later he'd passed away. It was such a shock to hear that. He'd been such an active person till he had the bad back, but this all stemmed from when he went into hospital in the April."
Mrs Evans said he had texted her to say he was quite worried and frightened after a patient had been "whisked away" to another ward and the whole area was deep cleaned after their departure.
She said she did not believe he could have caught the virus anywhere other than hospital as the family were shielding because of other vulnerable family members.
"We haven't been anywhere since mid-March other than I took him to the hospital for the MRI scan. There's nowhere else I can think he would have possibly come in contact [with the virus]."
Mrs Evans says she believes her husband - a former assistant head teacher at Bryn Celynnog Comprehensive in Beddau - received excellent care while he was in intensive care but was astonished when she was told he had coronavirus.
She never saw him again.
"It was shock but I just thought he'd simply get over it," she added.
"I didn't think for a minute that he wouldn't. I didn't think for a minute that he wasn't going to come home"
Wales following Scotland
Scotland has already been publishing details of patients who had been tested for coronavirus in hospital.
Up to 28 June more than 18,250 people in Scotland have been tested for coronavirus.
Nearly 72% acquired it in the community and another 3,500 (19.3%) were patients who tested positive within two days of arriving in hospital, put down to community infection.
There were more than 1,000 patients (5.8% of infections) who definitely caught Covid-19 while in hospital.
Another 272 patients were "probable".
The figures were released after it emerged 870 hospital patients were confirmed cases and 218 had died.
In the most recent week, Scottish figures show only one definite and two "probable" infections acquired in hospital.
Chris Jones, deputy chief medical officer for Wales, said every country had found similar issues but there was now a "very, very low chance" of infection.
It had not been known early on that people could carry the virus without showing any symptoms.
"When people came in with Covid we segregated them but others went on to the general wards," he said.
"Now we know we have to be very careful about that. We've been learning all along about the nature of this pandemic but this is a unique, first-time experience of this infection."
He said infection rates were now very low but data would now be monitored closely so there could be tight controls in place going forward.