Confused by health words? Check out our new plain English guide

April 5, 2020

Covid-19: A-Z plain English guide to words and terms


Asymptomatic, herd immunity and super spreader – just some of the terms explained in new A-Z guide

Many people find health information difficult to understand at the best of times, but over the last month we have been presented with a whole new set of medical words and terms. This is especially difficult for the one in six adults in Ireland who have literacy issues.

That’s why the National Adult Literacy Agency (NALA) has produced a plain English guide to many of the new words that we are hearing every day.

From asymptomatic to clusters, herd immunity to mitigations phases, and super spreaders to virologists, there are over 70 words and terms explained.



NALA is also making its tutors available on the phone to anyone who needs additional help understanding this information.

“The HSE is doing an amazing job at explaining everything to do with the Coronavirus (Covid-19). Their communications has been very clear and easy to understand. In Ireland there are over 500,000 people with low literacy and numeracy levels, and who will have greater difficulty understanding health information. That is why we produced this plain English guide to words and terms being used. Also, if anyone needs help reading or understanding health information please call us on our Freephone 1800 20 20 65 and we will try to help,” said Dr Inez Bailey, NALA CEO.


Have you heard of a Covidiot?

Apparently this refers to a stupid person who stubbornly ignores social distancing or who hoards things like toilet roll.

“Are you seriously going to visit granny? Don’t be such a covidiot.”
“See that guy with the 200 toilet rolls? What a covidiot.”


Selection of words explained:



This is where you are not showing any symptoms that you have COVID-19. However, you can still pass the virus on to others.

Chain of infection

This is how an infection spreads from one person to another. This can also be called chain of transmission.


This refers to a small group of people in a particular space who all have the same disease. For example, a cluster of people in nursing homes or hospitals.


This is where certain groups of people (such as over 65s and people with health issues) will stay in their homes to avoid contact with any person who may have COVID-19.

Community transmission

This occurs where a person who gets COVID-19:

  • has not travelled to an affected area, and
  • has no connection to a known case.

Herd immunity

This is when a high percentage of the community is immune to a disease, usually through vaccination and/or prior illness.

Incubation period

The time between when you are exposed to the virus and when symptoms and signs become obvious.


A state of isolation or restricted access put in place by the State to keep people safe against the spread of COVID-19.

Morbidity rate

This is the percentage of people who have a disease in the population.

Personal Protective Equipment (PPE)

This is equipment that will protect the user against health or safety risks at work. It includes for example masks, gloves, gowns and eye protection.

Super spreader

This is a person who infects significantly more people than usual. This is not a scientific term and has been used by the media.


This is a small piece of cotton wool used by a doctor or nurse for taking a specimen (sample of something).

If you need a test for COVID-19 a healthcare worker will take a sample from inside your mouth and nose using a swab.


A scientist or doctor who studies viruses and the diseases viruses cause.


For a full list of words see:

The words and definitions are taken and adapted from:


Need more help?

The National Adult Literacy Agency has tutors on the phone that can help adults with:

  • Reading, writing and spelling
  • Filling in forms, for example for social welfare benefit
  • Helping kids with school work
  • Understanding health information
  • Understanding financial information, for example applying for mortgage relief

Call us on Freephone 1800 20 20 65 or Text LEARN to 50050 and we will ring you back with more information and set you up with one of our friendly distance learning tutors.

Our phone is answered Monday to Friday 9.30am-5pm and we will reply to all texts within two days.




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