Image copyright Getty Images Image caption One in four kids, in the UK and US, has the virus that causes measles
Kids are getting measles at a higher rate than they did a few years ago.
Several outbreaks have occurred recently, in the US and UK, and there are concerns this could get worse as it has spread throughout Europe.
Last year – the last year for which there are complete figures – more than 2,300 people in Europe had measles.
However, there are several factors that may be responsible for this.
They include the measles vaccine, which is now covered by most countries’ vaccines programmes, and fast-rising immunisation rates among those under 15.
The World Health Organization says unvaccinated children are largely to blame, however – and it estimates that a number of unvaccinated children being raised in families where the disease is not brought up is a contributor.
Experts also believe some of the outbreak may be accidental, as unvaccinated people may simply fall ill and then become infected again – just as it happened in 2013, when a hepatitis A outbreak in Texas exposed unvaccinated people to a measles vaccine which they hadn’t got.
This week, Dr Kevin Emery from Public Health England told the BBC that there were about 1,500 measles cases in England in 2016, equivalent to about 400 cases annually.
Earlier this year, the UK recorded its highest number of cases in 17 years – 1,200 cases of measles, defined as having three or more symptoms over a seven-day period.
The Health Protection Agency (HPA) said it had been busy alerting doctors and other public health professionals about the outbreak, because MMR coverage rates for this age group has steadily decreased, from about 95% in 2010 to about 80% in 2016.
The HPA estimates that as many as 500 young people aged between five and 14 may have been exposed to the disease in England.
Vaccines may be increased
Public Health England said that the “very unusual” measles outbreak in the United States last year, where there were 1,175 measles cases, could help to stop more people in the UK from catching the disease.
Several anti-vaccination campaigns were thought to have contributed to the outbreak, including a measles-mumps-rubella vaccination campaign and social media messages urging families to forgo vaccinations.
How the virus spreads
Image copyright Getty Images Image caption The most common symptoms are high fever, cough, runny nose and red eyes
Image copyright Getty Images Image caption Handwoven wall hangings used in Pakistan are infected by the virus
Image copyright Getty Images Image caption Symptoms of measles normally start with high fever, cough, runny nose and red eyes. Little kids can also have mumps
Image copyright Getty Images Image caption By the time rash appears around six to 10 days later, it is a contagious condition
Image copyright Getty Images Image caption Severe symptoms can include bloody diarrhoea, eye and ear infections and pneumonia
Image copyright Getty Images Image caption The virus isn’t airborne
Image copyright Getty Images Image caption MMR vaccine offers an 90% protection against measles, with immunity building up gradually
Image copyright Getty Images Image caption People at high risk from measles are young children, pregnant women and people with existing health conditions
Image copyright Getty Images Image caption Infection and treatment can be life-threatening, particularly for young children
Image copyright Getty Images Image caption Vomiting can happen within a few hours of an infection and the rash may not appear for a couple of days after
Image copyright Getty Images Image caption Ribs and fingers become swollen and infected after measles is ingested
Image copyright Getty Images Image caption People with measles are contagious for a few days before symptoms appear
Image copyright Getty Images Image caption Symptoms of measles are often similar to flu, but start on a different day
Mixed-use items such as cutlery, towels and other towels containing polyurethane materials are also involved in spreading the virus in homes, schools and hotels.
Dr Emery said that because measles has developed a “return to host” virus such as rubella, infections may start inside the community rather than through deliberate contact with infected people.
“It may not be as severe or as long lasting as a more acute disease.”
Image copyright Getty Images Image caption Measles vaccination is recommended for those between 12 and 17 years old, with boosters for teenagers and adults after that
Image copyright Getty Images Image caption There was one confirmed measles case in Wales last year, and 22 across the rest of the UK
Image copyright Getty Images Image caption UK measles cases recorded last year