How worried should I be about measles? A doctor’s guide to a highly infectious disease

Measles spreads very easily among those who are unvaccinated. In some children it is very serious, leading to hospitalisation and even death in rare cases

There is an air of concern about the threat of a national outbreak of measles in Ireland following the death of a man this week.

Both the Chief Medical Officer and Minister for Health Stephen Donnelly say they are particularly worried about the threat, especially with a marked rise of measles cases having occurred in the UK and across Europe.

Q. It is unusual to hear of the death of an adult in an Irish hospital due to this disease. Should we be worried about this?

A. While vaccination programmes are primarily aimed at protecting infants from measles, cases do occur in adults. The infection is generally more severe in adults. The man who died may have been older or may have had a condition that weakened his immune system, rendering him less able to fight the infection. He may also have been in the cohort of young men (one in five aged 18-21) who we know are vulnerable because they are not inoculated against the highly contagious virus.


Q. Measles, mumps and rubella vaccination (MMR) was introduced in the mid 1980s – do people born before then have any protection against measles infection?

A. For people born before 1957, immunisation is not recommended because they were likely infected naturally as children and are presumed to be protected against measles, mumps and rubella. However, adults born between 1957 and the introduction of the MMR vaccine in 1985 may not be protected against measles. They should consider attending their GP for MMR vaccination, which consists of two shots given 28 days apart. Two doses of the vaccine gives lifelong protection – it is never too late to catch up.

Q. How is measles spread?

A. Measles is one of the most infectious viruses in the world. It is much more contagious than either Covid or influenza. It is transmitted person-to-person via droplets when infected people sneeze or cough. It is spread by contact with infected nasal or throat secretions when a person with the disease coughs or sneezes, or by breathing air that was breathed by someone with the disease. The virus can stay active and contagious in the air or on surfaces for up to two hours.

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Measles spreads very easily among those who are unvaccinated, especially in creches and schools. It can be an unpleasant illness and in some children is very serious, leading to hospitalisation and even death in rare cases. People in certain at-risk groups, including babies and young children, pregnant women, and people with weakened immunity, are at increased risk of complications from measles.

Q. What symptoms should you look out for?

A. Initial symptoms usually occur 10–12 days after infection and comprise high fever, runny nose, bloodshot eyes and tiny white spots on the inside of the mouth. Several days later, a rash develops on the face and neck, and will gradually spread to the rest of the body. The most severe complications of measles include blindness, encephalitis (an infection that causes brain swelling), severe diarrhoea and pneumonia.

Q. How can I protect myself from measles?

A. The best protection is by immunisation. Between 97 and 99 per cent of those who have two doses of the MMR vaccine will be protected against measles. But we are also reliant on a sufficient percentage of the population partaking in the national vaccination programme. We need at least 95 per cent vaccine coverage to achieve a state of herd immunity, whereby the virus cannot cause outbreaks. There is no specific treatment for measles infection.

Q. Could Covid-19 have played a role in the current outbreaks?

A. The closure of schools, shops and other settings during the Covid pandemic would have reduced transmission of measles. Combined with reduced vaccination rates due to the allied disruption of immunisation programmes, it meant that once Covid restrictions were eased, there was a larger pool of susceptible people. It is likely the pandemic is at least partially to blame for the current worldwide outbreaks of measles.

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