Parents in Wales have been warned to make sure their children are vaccinated after an outbreak of measles.
Health officials have reported an increase in measles cases in Ceredigion, while more possible outbreaks are being investigated in Swansea, Pembrokeshire, the old Gwent area, Powys, Carmarthen and Neath Port Talbot.
There are believed to be 10 cases in Ceredigion and a further 20 elsewhere.
Dr Rolan Salmon, regional epidemiologist for Public Health Wales, revealed that most of the sufferers being investigated had not been given their scheduled vaccinations.
Children aged under five are especially vulnerable to complications caused by measles, with the disease having the potential to be fatal.
Dr Salmon said: "We are urging parents throughout Wales who have not arranged immunisation for their children to act immediately to get them vaccinated."
Dr Richard Roberts, who is head of the vaccine preventable disease programme run by Public Health Wales, stressed that MMR is a "safe and effective vaccine".
He said that the only way to make sure the measles outbreaks could be restricted and prevented in future is if 95% of children in Wales receive two doses of the MMR vaccine.