New research suggests that anywhere between 10% and 20% of Covid-19 patients are still unwell, and require ongoing medical treatment, at least 12 weeks after becoming infected.
In Ireland, there have been 269,793 Covid-19 cases, so 53,958 of these people could develop long Covid-19 and the associated health problems.
But what do we know about the condition?
Long Covid, also known as post-Covid syndrome, is used to describe the effects of the virus that continue for weeks or months beyond the initial illness.
The most recent study from Imperial College London suggests the most common symptoms were tiredness and muscle aches.
While in a second group they were shortness of breath affecting normal activities, tightness in the chest and chest pain, with more people reporting that they had severe symptoms.
Previous research has indicated a range of other symptoms, including fatigue, problems with memory and concentration, insomnia, dizziness, pins and needles, joint pain, depression and anxiety, tinnitus, earaches, feeling sick, diarrhoea, stomach aches, loss of appetite, a high temperature, cough, headaches, sore throat, changes to sense of smell or taste or skin rashes.
Long Covid is higher among women, people who are overweight or obese, those who smoke, people who live in deprived areas, or those who had been admitted to hospital.
The prevalence of the condition also increases with age.
According to the research, persistent Covid-19 symptoms were lower in people of Asian ethnicity.
It is not yet known how long symptoms may last, but previous research has found people reporting effects 36 weeks – or nine months – after infection.
Elsewhere some people have reported catching Covid in March 2020 and still suffering long-term effects now.
Scientists from the UK’s National Institute for Health Research suggest ongoing Covid may not be one illness but at least four different syndromes.
These have been broadly categorised as: post-intensive care syndrome, post-viral fatigue syndrome, permanent organ damage and long-term Covid syndrome.
There are currently no dedicated long Covid units within the HSE, although there have been calls for one.
People are urged to contact their GP if they are worried about symptoms four weeks or more after having Covid-19.