O ddechrau’r achos ym mis Tachwedd 2012 hyd at 16 Mai 2013, mae 1,105 o achosion wedi’u nodi yn yr ardal, gyda 1,292 o achosion ledled Cymru. Cafwyd 87 o achosion o gyfnodau yn yr ysbyty.
From the start of the outbreak in November 2012 to 16 May 2013, there have been 1,105 cases notified in the outbreak area with 1,292 cases notified across Wales. There have been 87 hospitalisations.