Key facts

• Measles is a highly contagious airborne infection which primarily affects children but can occur at any age.
• Symptoms include fever, cough, runny nose, and a characteristic red rash.
• In some cases the disease can be fatal or lead to life-changing complications, particularly in very young children
• The disease is preventable through vaccination but cases are rising due to a fall in the number of children receiving the jab

Overview

Measles is an acute viral illness which, before the widespread introduction of the measles vaccine, caused major epidemics every two to three years. Outbreaks of this highly infectious disease continue to occur, largely due to low vaccination rates.

The disease is characterised by an initial phase of non-specific symptoms followed by a distinctive rash. While many cases are mild and will clear up on their own, measles can be dangerous, especially in young children, those with weakened immune systems and pregnant women.

Signs and symptoms

The first few days after infection is marked by a feeling of general tiredness and non-specific symptoms. Common symptoms include:

• High fever
• Cough
• Runny nose
• Red, watery eyes
• Small white spots inside the mouth
• Fatigue and general malaise.
• Red blotchy rash spreading from face to body (this occurs about seven days after infection)

Dangers and complications

Measles can lead to serious complications, particularly in young children, pregnant women, and individuals with weakened immune systems. In the United States, one in five unvaccinated people who get measles ends up in hospital.

Complications may include:

• Ear infections, potentially leading to hearing loss
• Diarrhoea and dehydration
• Pneumonia, which is the most common cause of death from measles
• Encephalitis, causing brain swelling and possible long-term damage such as deafness or intellectual disability
• Eye damage or blindness
• Subacute sclerosing panencephalitis (SSPE), an incredibly rare but fatal progressive neurological disorder occurring years after infection.

Transmission

Measles is one of the most contagious of all diseases. It spreads through respiratory droplets when an infected person coughs or sneezes. The virus can remain in the air or on surfaces for up to two hours.

People can spread the disease from around four days before they start showing symptoms and are typically infectious four days after the rash appears. Unvaccinated individuals in close contact with an infected person are at very high risk of contracting the virus.

Treatment

There is no specific antiviral treatment for measles. Management focuses on reliving symptoms and preventing complications. Care includes:

• Ensuring adequate hydration and nutrition
• Fever control
• Treating secondary bacterial infections with antibiotics if necessary
• If a patient is hospitalised they may also be given vitamin A supplements to prevent eye damage.

Prevention

Vaccination is the most effective method of preventing measles. In the UK the measles vaccine is given in a three-in-one jab with mumps and rubella – and from January 2026 will be in a four-in-one jab with varicella (chicken pox). The first dose is given at one year and the second has recently been brought forward to be given at 18 months of age. In the UK children born on or before June 30 2024 will receive their second dose at three years four months.

Other preventive measures include:

• Ensuring high vaccination coverage in communities to maintain herd immunity
• Isolation of infected individuals to prevent spread
• Good hygiene practices such as frequent handwashing and covering the mouth when coughing or sneezing
• Prompt vaccination of susceptible individuals during outbreaks to contain transmission

History

Measles has been around for millennia, with the first reported account by a ninth century Persian doctor. The Scottish physician Francis Home discovered it was an infectious agent in 1757 and the first vaccines were developed in the US in the 1950s, with mass vaccination introduced from the 1960s onwards.

Before widespread vaccination global outbreaks of the disease took place every two to three years, leading to millions of cases and deaths. But cases are still high: in 2023 an estimated 107,000 people – mostly children under the age of five – died from the disease.

The disease is a threat wherever vaccination levels are low and in 2023 the number of children globally receiving a first dose of measles vaccine was 83 per cent, down from 86 per cent in 2019. The WHO says 95 per cent of children need to be vaccinated to prevent outbreaks.

The MMR vaccine became a touchstone for the anti-vax movement after the 1998 publication of fraudulent research linking it to autism. However, most experts attribute falling vaccination rates to a lack of access rather than scepticism.

The UK lost its measles elimination status in 2019 and in August 2025 the government warned nearly one in five children had not received their pre-school vaccine booster.

Useful links

cdc.gov/measles/signs-symptoms

who.int/fact-sheets/measles

nhs.uk/conditions/measles

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