The measles symptoms you need to know – as UK health chief Jenny Harries says urgent action is needed to stop the infection’s spread across the country

A measles outbreak will spread across Britain unless more people take the vaccine, health officials have warned.

Authorities have declared a national emergency in light of falling vaccination rates, highlighting the growing risk to public health.

Dame Jenny Harries, chief executive of the UK’s Health Security Agency, said vaccination rates were “well below” what is recommended by the World Health Organisation.

With vaccination rates falling to a decade low, only half of children in parts of London have had a measles, mumps and rubella (MMR) vaccination.

In addition to London, there are particular concerns around regions such as Liverpool, Manchester and the West Midlands.

Measles usually starts with cold symptoms before causing a rash consisting of small red spots, some of which may feel slightly raised. According to the NHS, it usually starts on the face and behind the ears before spreading further

White spots in the mouth also often appear a few days after the first symptoms.  These last a few days

White spots in the mouth also often appear a few days after the first symptoms. These last a few days

Symptoms of a measles infection:

The first symptoms of measles include:

  • A high temperature
  • A runny or stuffy nose
  • To sneeze
  • A cough
  • Red, painful, watery eyes

The second phase includes:

Small white spots appear in the cheeks and on the back of the lips

The final and third phases include:

A red, blotchy, non-itchy rash that starts on the face and behind the ears before spreading to the rest of the body

People are being urged to get the MMR jab against the potentially deadly virus, with pop-up clinics being introduced to get more children vaccinated as cases continue to rise.

Measles is a highly contagious disease that spreads through coughing and sneezing, with a series of symptoms manifesting in a series of stages.

It can take up to two weeks for symptoms to even appear.

The infection usually starts with cold symptoms, followed by a rash a few days later, with some people developing small spots in their mouths.

The cold-like symptoms may include:

  • A high temperature
  • A runny or stuffy nose
  • To sneeze
  • A cough
  • Red, painful, watery eyes

Typically, patients with the next stage of measles, which occurs a few days after cold symptoms, develop white spots in their mouths.

These can appear in the cheeks and on the back of the lips, according to the NHS, and usually last a few days.

The telltale measles rash appears a few days later.

The rash usually starts on the face and behind the ears before spreading to the rest of the body, with the spots of the rash sometimes raising and joining together to form blotchy patches. They usually don’t itch.

On white skin the rash looks brown, but on brown and black skin it can be harder to see.

Seven to fourteen days after the measles infection, the first symptoms appear, including high fever or fever (Photo: Getty/iStockPhoto)

Seven to fourteen days after the measles infection, the first symptoms appear, including high fever or fever (Photo: Getty/iStockPhoto)

The infection usually starts with cold symptoms, including sneezing and a runny, stuffy nose (Photo: Getty)

The infection usually starts with cold symptoms, including sneezing and a runny, stuffy nose (Photo: Getty)

It is estimated that one in five children who become infected will be hospitalized, with one in fifteen developing serious complications such as meningitis or sepsis.

At least 95 percent of the population must be vaccinated to prevent outbreaks, guided by public health.

But nationally the percentage of five-year-olds fully vaccinated has fallen to 84.5 percent – the lowest in more than a decade.

Dame Jenny pleaded with parents to check their child’s vaccination status, warning that the public had ‘forgotten what measles is like’ and that it was still a ‘serious disease’.

She also called on the “Wakefield generation” – adults born in the late 1990s or early 2000s – to check their own medical records.

Meanwhile, the measles hotspots in England have been revealed by MailOnline in an interactive map, showing the number of cases detected in each local authority in England, Wales in December.