Cwm Taf Health Board says patients who may have been treated by a healthcare worker infected with Hepatitis C at the old East Glamorgan Hospital in Pontypridd will be asked to ring a dedicated helpline to arrange an appointment in a specialist nurse clinic.
Nicola John, director of public health at Cwm Taf Health Board, said: "We know this will be a very worrying time for patients who may have received obstetric and gynaecology treatment at East Glamorgan General Hospital between May and July 1984."
"However, we want to stress the risk of transmission to patients is small. But it is important that we get in touch with patients who may have been in contact with this worker during their treatment, which is why we are writing to some former patients, to ask them to contact the helpline."
The appointments helpline is open from today, from 8am to 8pm, seven days a week. Specialist clinics will start taking place from 13th September 2013 and patients who have tests will get their results in approximately two weeks.
A hospital in Rhondda Cynon Taf will be temporarily reducing the number of beds on its dementia assessment ward while refurbishment work is carried out.
The number of beds in the Seren ward at the Royal Glamorgan Hospital will go down from 30 to 20 from the start of January.
The hospital says the work, which will involve removing existing walls and building new ones, is necessary to ensure patients "continue to be treated in a high-quality environment".
The health board says that patients who need a hospital assessment during the refurbishment work will be admitted to Seren ward if beds are available or to a bed elsewhere in Cwm Taf Health Board area until one becomes free on Seren ward.
A woman who complained to Cwm Taf Health Board about her mother's treatment has had her complaint upheld by the Ombudsman for Wales.
The daughter complained that after taking her mother to Royal Glamorgan Hospital clinicians failed to take appropriate action after a blood test result indicated that she could have thrombosis.
Her mother died two days after she was discharged in May 2010.
Pulmonary thromboembolism was recorded as the main cause of death.
The Ombudsman said that the daughter believes if prompt action had been taken after the result came back as positive then her mother's death could have been prevented.
An investigation found that the test was seen by a nurse before the mother was discharged and that her blood result was positive.
It found that the test result did not seem to have been "appropriately considered, if at all" by the doctor who made the decision to discharge her, or by the consultant who had overall responsibility for her care.
The Ombudsman concluded:
"The failure to consider and act on the positive test result before making the decision to send the mother home fell below an acceptable standard of care. This failing gave rise to a missed opportunity to make the correct diagnosis and to treat her appropriately.
" The treatment that should have been given might have prevented her death.The investigation also identified a number of additional failings on the part of the health board."
The complaint was upheld by the Ombudsman and it was recommended that the health board should provide explanations and an apology to the patient's daughter.
The health board was told to pay £5,000 to Mrs Y's family.