A healthcare worker infected with Hepatitis C is known to have transmitted the virus to two patients.
Now, further patients who may have been treated by them are being contacted and offered advice and blood tests.
The healthcare professional worked at:
- Caerphilly District Miners’ Hospital, between May 1984 and July 2003
- East Glamorgan Hospital, in Pontypridd, between 28 May 1984 and 17 July 1984
- Maelor General Hospital, in Wrexham, between 15 May 1978 and 27 June 1978
More top news
Plaid Cymru demands an urgent Senedd debate and Labour launches a consultation on the UK's future as the process of leaving the EU begins.
Last year, more than 10,500 complaints of abuse were investigated by the charity.
French presidential candidate Francois Fillon's wife has been handed preliminary charges in connection with the alleged "fake jobs" scandal.