Parents across North Wales are being urged to ensure that their children are up to date with both doses of the MMR vaccination following an increase in the number of measles cases across Gwynedd.
There are 37 laboratory confirmed cases with a further 16 cases under investigation bringing the total number associated with the outbreak to 53. There were just 19 laboratory confirmed cases of measles across Wales throughout 2011.
The majority of cases are in older primary or young secondary school children who are not up to date with their MMR dose.
Dr Chris Whiteside, consultant in communicable disease control for Public Health Wales, said: 'Measles is highly infectious and spreads very easily. Complications are quite common even in healthy people and can be very serious.
'The measles virus is now circulating in the community. Therefore, all those not protected by two doses of MMR vaccine are at risk of catching the disease.'
Children should receive their first dose of the vaccine at around one year old, and the second dose at around three years and four months of age.
General practices across North Wales are offering vaccinations to local children who have not had both doses of the MMR vaccine. Children who have not been vaccinated will be contacted by the NHS.
Dr Whiteside continued: 'The only way to prevent outbreaks of measles is to ensure that at least 95 per cent of children in Wales have received two doses of the MMR vaccine. Although more children are having the vaccine now, we still have some way to go before we can guarantee the safety of children in Wales from measles.'
More information about measles is available from the Public Health Wales website.