The worst affected areas are: Abertawe Bro Morgannwg, which as well as Swansea also includes Neath, Port Talbot, and Bridgend; there are also cases in Powys and the Hywel Dda Health Board area, which covers Carmarthenshire, Ceredigion, and Pembrokeshire.

Uptake of MMR vaccine has improved recently and almost 600 immunisations were carried out last week. Health officials estimate that around 3800 children are not fully immunised against measles. The immunisation campaign will continue in schools when the pupils return following the Easter break.

Advice for Travellers

It should be confirmed that children have received their recommended doses of MMR at 12-15 months of age and again pre-school around 3 years 6 months, while unimmunised adults who have not had the disease themselves may consider vaccination if thought to be at risk. Two doses of MMR vaccine are required to give adequate protection.