It was confirmed on Wednesday that measles is circulating in Leeds, so here is how to spot the disease.
We reported yesterday how Public Health England (PHE) has reported an increase in measles across the country and said there are three confirmed and four suspected cases of measles in Leeds since the beginning of October.
Those affected are said to be recovering, but the agency is encouraging people in the city to check they and their children have had two doses of MMR vaccine.
Here are NHS guidelines on how to spot the highly infectious disease that is most common in young children and what to do if you are concerned:
Symptoms of measles
The initial symptoms of measles develop around 10 days after you're infected. These can include:
cold-like symptoms, such as a runny nose, sneezing, and a cough
sore, red eyes that may be sensitive to light
a high temperature (fever), which may reach around 40C (104F)
small greyish-white spots on the inside of the cheeks
A few days later, a red-brown blotchy rash will appear. This usually starts on the head or upper neck, before spreading outwards to the rest of the body.
When to see your GP
You should contact your GP as soon as possible if you suspect that you or your child may have measles.
It's best to phone before your visit as your GP surgery may need to make arrangements to reduce the risk of spreading the infection to others.
You should also see your GP if you've been in close contact with someone who has measles and you've not been fully vaccinated (had two doses of the MMR vaccine) or haven't had the infection before – even if you don't have any symptoms.
Is measles serious?
Measles can be unpleasant, but will usually pass in about 7 to 10 days without causing any further problems.
Once you've had measles, your body builds up resistance (immunity) to the virus and it's highly unlikely you'll get it again.
However, measles can lead to serious and potentially life-threatening complications in some people. These include infections of the lungs (pneumonia) and brain (encephalitis).
Read more about the complications of measles.
How measles is spread
The measles virus is contained in the millions of tiny droplets that come out of the nose and mouth when an infected person coughs or sneezes.
You can easily catch measles by breathing in these droplets or, if the droplets have settled on a surface, by touching the surface and then placing your hands near your nose or mouth. The virus can survive on surfaces for a few hours.
People with measles are infectious from when the symptoms develop until about four days after the rash first appears.
How measles can be prevented
Measles can be prevented by having the measles, mumps and rubella (MMR) vaccine.
This is given in two doses as part of the NHS childhood vaccination programme. The first dose is given when your child is around 13 months old and a second dose is given before your child starts school.
Adults and older children can be vaccinated at any age if they haven't been fully vaccinated before. Ask your GP about having the vaccination.
If the MMR vaccine isn't suitable for you, a treatment called human normal immunoglobulin (HNIG) can be used if you're at immediate risk of catching measles.
There are several things you can do to help relieve your symptoms and reduce the risk of spreading the infection, including:
taking paracetamol or ibuprofen to relieve fever, aches and pains – aspirin should not be given to children under 16 years old
drinking plenty of water to avoid dehydration
closing the curtains to help reduce light sensitivity
using damp cotton wool to clean the eyes
staying off school or work for at least four days from when the rash first appears
In severe cases, especially if there are complications, you or your child may need to be admitted to hospital for treatment.
How common is measles?
The effectiveness of the MMR vaccine means that cases of measles are uncommon in the UK nowadays. However, the number of cases has risen in recent years and there have been some high-profile outbreaks.
For example, between November 2012 and July 2013 there was an outbreak in and around Swansea, during which more than 1,200 cases were reported.
It's thought the rise in the number of cases of measles is the result of parents not getting their child vaccinated with the MMR vaccine, probably because of speculation linking MMR to autism.
Publicity in 1998 highlighted a report claiming there was a link between the MMR jab and autism. However, numerous studies undertaken to investigate this claim found no link between the MMR vaccine and autism.