of the 271,343 positive cases that were eligible for follow-up, 264,380 (97.4%) were reached and asked to provide details of their recent contacts
o blith y 271,343 o achosion positif a oedd yn gymwys i'w holrhain, cyrhaeddwyd 264,380 (97.4%) a gofyn iddynt ddarparu manylion y bobl y maent wedi dod i gysylltiad â nhw yn ddiweddar