The look-back exercise involved locating and reviewing a significant number of case notes to identify those patients who may have been exposed to this infection.
Yn ystod yr ymarfer adolygu, cafodd nifer sylweddol o nodiadau achos eu lleoli a’u hadolygu i adnabod y cleifion hynny a allai fod wedi dod i gysylltiad â’r haint hwn.