Measles is a highly infectious viral disease which can lead to serious complications such as pneumonia and encephalitis (inflammation of the brain). In addition, measles infection damages and suppresses the whole immune system. This means that people who have had measles are more likely to catch other infectious diseases. This effect can last for as much as three years after they recover from measles (see 'More Information' below).

In high income regions of the world such as Western Europe, measles causes death in about 1 in 5000 cases, but as many as 1 in 100 will die in the poorest regions of the world. Worldwide, measles is still a major cause of death, especially among children in resource-poor countries. In 2016 about 90,000 people died of measles. This was the first year on record when global measles deaths fell below 100,000 a year. However, in 2017 global measles deaths rose by over 20% to 110,000 deaths - over 300 deaths a day. This increase was due to gaps in vaccination coverage. See the World Health Organization report .

Over the last twenty years vaccination has dramatically reduced the number of deaths from measles. Since 1990 (when measles killed 872,000 people), it is estimated that over one in 5 of all child deaths averted have been due to measles vaccination. Since a measles vaccine was introduced in the UK in 1968, Public Health England estimates that 20 million measles cases and 4,500 deaths have been averted in the UK.

Current measles risks in the UK and Europe

Between 2001 and 2013 there was a sharp rise in the number of UK measles cases, and three people died. Numbers of cases have fallen since 2013, but rates of measles are still higher than they were in the late 1990s. In 2018 there were 966 laboratory confirmed measles cases in England - nearly four times as many as the total number confirmed in 2017 (259 cases). The majority of measles cases have been in people who are not vaccinated, especially young people aged 15 and over who missed out on MMR vaccination when they were younger. About 30% of those infected have been admitted to hospital.

At the moment most UK measles cases are linked to travel in Europe. Measles cases have also been linked to music festivals and other large public events. Public Health England is advising people to check that they are vaccinated against measles before they travel abroad or go to large public events in the UK or elsewhere.

Numbers of measles cases are currently high in several European countries. There were over 82,500 measles cases in Europe in 2018 . This is more than three times as many as in 2017, and 15 times as many as in 2016. In 2016 and 2017 there were 49 deaths from measles in Europe, and 2018 saw another 72 deaths. Some countries have reported that over 60% of measles cases have been hospitalised. There have been particularly serious outbreaks in Serbia, Ukraine, Georgia, Greece, Romania, Italy, and France, with over 40% of cases in Europe occurring in adults over the age of 20. See the regular reports from the European Centre for Disease Prevention and Control.

Travellers have brought a number of measles cases into the UK recently, and these are expected to continue. All travellers are advised to check that they are up to date with MMR vaccination before they travel. If you are travelling with a baby, the MMR vaccine can be given from six months of age before travelling to a country where measles is a risk or where an outbreak is taking place. See the Travel Health Pro website for more information.

In the short film below, experts talk about measles and its complications, and the importance of the MMR vaccine.