GOV.WALES uses cookies which are essential for the site to work. Non-essential cookies are also used to tailor and improve services. By continuing to use this site, you agree to our use of cookies.
You are here:
Noun, Masculine, Singular
achosion cyfeirio
Yr achos cyntaf a ddogfennir gan yr awdurdodau o glefyd mewn poblogaeth benodol.
Cymharer รข 'primary case' / 'achos gwreiddiol'.