During the three fatal outbreaks at Craigavon Area Hospital (CAH) and Daisy Hill Hospital (DHH) in 2020, which were examined for the report, 15 of the 32 affected patients died.
The wards involved cared for haematology, medical and surgical patients - and many patients and healthcare workers were affected.
The report follows the establishment of an independent expert panel by the Southern Health and Social Care Trust, chaired by Dr Guduru Gopal Rao, a consultant microbiologist from the London North West University Trust
It found that in the Haematology Ward outbreak, seven of the 14 patients with Covid-19 (50%) died; in the Male Medical Ward outbreak, six of the 13 patients with Covid-19 (46.2%) died and in the 4S Ward outbreak, two of the five patients with Covid-19 (40%) died.
The age range of the deceased was between 65 and 84 years. There were 11 males and four females.
Many of the deceased patients had severe pre-existing comorbidities (the existence of more than one disease or condition within a body at the same time) and limited life expectancy prior to contracting Covid-19.
The panel concluded that Covid-19 appears to have contributed to the premature death of 12 of the 15 infected patients.
Poor ward environments exacerbated difficulties in managing social distancing for patients and healthcare workers, the report found.
The report also states that inconsistent and inadequate information was provided to patients and family regarding the outbreaks.
In the wards, there was insufficient and inadequate isolation and toilet facilities, as well as poor ventilation.
While patients were screened on admission, there was no screening of inpatients or healthcare workers at regular intervals.
This hampered early detection and the implementation of control measures before the spread of infection.
In addition, symptoms of sepsis and fever occur commonly in immunosuppressed haematology patients - making it difficult to clinically diagnose Covid-19 in these patients.
In CAH, relaxing of restrictions for ward visits at the time of the outbreaks and the use of fans are likely to have contributed to the outbreak.
The panel found instances of inconsistent and inadequate communication with patients, families and healthcare workers.
In many cases, there were no records of communication of Covid-19 test results to the patients or their families.
Patients and their families were provided with little specific information regarding the outbreaks, which the report found may have led to confusion regarding isolation requirements and visiting restrictions.
The report states: "The impact of the outbreaks was catastrophic, with profound implications for the patients, families and healthcare workers involved.
"It resulted in the loss of loved ones, treatment delays, extended admissions and prolonged effects in some patients and healthcare workers.
"Patients, families, and healthcare workers also reported ongoing emotional impacts of the outbreak."
Families and patients commented on delays in accessing care; the lack of continuity of care as a result of transfers between wards and hospitals; prolonged hospital stays, too many visitors on the wards, overcrowding and lack of social distancing amongst healthcare workers and patients, improper use of PPE, poor infection control practice, excessive use of temporary healthcare workers, and poor communication.
Healthcare workers commented on the poor state of the wards and poor ventilation, the inability to maintain adequate social distancing on the wards and in healthcare workers' facilities, inadequate and inappropriate supply of PPE, excessive number of visitor, difficulties in trying to keep up with changing and sometimes conflicting infection control guidance, and poor communication regarding the progress of the outbreaks.
A Southern Trust spokesperson said: "The review referred to the catastrophic impact of these outbreaks and we fully recognise the enormous distress experienced by the families and hospital staff affected."
The Department of Health welcomed the publication of the report, saying it contains helpful recommendations for strengthening infection prevention and control measures as well as the systems for overseeing and ensuring best practice across Health and Social Care in Northern Ireland.