Public Health Wales say that the number of cases of measles in the Swansea area has reached 252.
Within the past week, 43 new cases have been reported.
The disease has now spread to children in 64 secondary and primary schools and nurseries across the area, with numbers of new cases doubling weekly.
The majority of the new cases are in the Swansea area, but cases are being reported across South East Wales.
– Dr Marion Lyons, Director of Health Protection for Public Health Wales
The continuing spread of the disease in the Swansea area means that it is only a matter of time before we have a child whose health is seriously damaged by measles.
We are urging parents of unvaccinated children to make immediate arrangements with their GP for their children to receive the safe and highly effective MMR vaccine.