Mae Sefydliad Iechyd y Byd wedi cael gwybod am y clwstwr gan Iechyd Cyhoeddus Cymru o dan ei rwymedigaethau Rheoliadau Iechyd Rhyngwladol o ganlyniad i natur anghyffredin a difrifol yr achosion.
The World Health Organisation has been informed about the cluster by Public Health Wales, under its International Health Regulations obligations because of the unusual and severe nature of the cases.