Swansea East AM Mike Hedges was diagnosed with measles as a youngster, along with his sister.
While he escaped permanent damage, his sister wasn't so lucky - she was left profoundly deaf.
David Wood reports on the potential dangers of measles and the efforts being made to combat the spread.
2013 is expected to be the worst year for measles in the UK for the past two decades. Read more about the illness and how it is treated.
If the Government's top adviser on immunisation thinks the risk of an emergency in England is a possibility, I believe him.