Another 12 deaths have been linked to hospital infections in the Cwm Taf Morgannwg health board area, bringing the total so far to 69.
The deaths have happened at its three general hospitals in Llantrisant, Merthyr Tydfil and Bridgend.
It comes as official figures report another 47 deaths in Wales involving Covid-19 registered in the latest week.
This is the highest weekly figure since mid-May reported by the Office for National Statistics (ONS).
It is 10 more deaths than reported the week before.
Cwm Taf Morgannwg health board said there were now 366 cases linked to outbreaks at the three general hospitals and two community hospitals in Rhondda and Maesteg.
Deaths included in the outbreaks are patients whose deaths are associated with the virus, not necessarily directly due to Covid-19.
There have now been 47 deaths at the Royal Glamorgan Hospital, 11 at the Prince Charles Hospital and 11 at the Princess of Wales Hospital.
Rhondda Cynon Taf has the ninth highest total death rate per 100,000 people involving Covid-19 across England or Wales, with a total of 353 deaths registered so far in the pandemic.
Analysis by the BBC shows the area now also has one of the fastest-rising case rates in the UK for Covid-19 infections, based on positive results.
Health board medical director Nick Lyons said: "Infection rates continue to rise at a concerning rate in our communities.
"It is up to all of us as individuals to take seriously our responsibilities and to adhere to the restrictions of the 17-day lockdown period. By doing this, you will be helping us to get this virus under control and protect everyone, including the most vulnerable, in our communities."
Conservative health spokesman in the Senedd, Andrew RT Davies, who repeated his call for an inquiry into hospital-acquired infections, called for a "serious focus" on the issue.
"Deaths linked to hospital-acquired Covid infections is turning into a real scandal in the second wave and my deepest sympathies go to the families of those who've tragically died," he said.
The separate ONS figures, covering the week ending 16 October, reveal 15 deaths happened in hospitals in the Cwm Taf Morgannwg area, 10 in Aneurin Bevan, five each in Betsi Cadwaladr and Cardiff and Vale and three in Swansea Bay.
There is a time lag in the ONS figures being published, compared to the daily Public Health Wales bulletin, to allow for deaths to be registered.
But the ONS also gives deaths in care homes, hospices and people's own homes, as well as hospitals.
Ten of the hospital deaths involved patients from Rhondda Cynon Taf. Across England and Wales, Liverpool saw the most deaths in hospital for this week with 29.
So-called excess deaths, which compare all registered deaths with previous years, are above the five-year average in Wales.
Comparing with the number of deaths we would normally expect to see at this point in the year is seen as a useful measure of how the pandemic is progressing.
In Wales, the number of deaths rose to 688 in the latest week, which was 58 deaths higher than the five-year average.