Flu patients could suffer from symptoms similar to long Covid - study

28 September 2021, 23:19 | Updated: 28 September 2021, 23:29

A study has found that some patients suffer from 'long flu'. Picture: Alamy

By Daisy Stephens

People who get flu could have prolonged symptoms which are similar to those seen in some patients with long Covid, a new study suggests.

The research, led by academics from the University of Oxford and the National Institute for Health Research (NIHR), found that some people who had flu continue to experience symptoms three to six months after infection, although they are less likely to suffer long-term effects than people with Covid-19.

The long-term symptoms reported in the study included abnormal breathing, mental health symptoms such as anxiety or depression, chest pain, cognitive problems and abdominal symptoms.

All of the symptoms reported were more common in Covid sufferers than flu sufferers.

"We found in a cohort of patients with influenza that the same symptoms also tend to occur, but they tend to occur at lower rates," said NIHR academic clinical fellow Dr Max Taquet, who led the analysis.

The team estimated that symptoms linked to long Covid were around 50 per cent more common among those who had a Covid-19 infection compared to those who had flu.

Biden gets Covid-19 booster shot after authorisation

The study, which analysed health records of more than 273,000 people who had Covid and 114,000 who had flu in the US, outlined a total of nine long Covid symptoms people were suffering with between 90 and 180 days after initial infection.

The analysis found that around 30 per cent of people who had flu experienced some sort of symptoms three to six months later compared to around 42 per cent of those who had Covid-19.

Professor Paul Harrison, who headed the study which has been published in the journal PLOS Medicine, from the Department of Psychiatry at the University of Oxford, said: "There are various post-viral conditions recognised and many of us who have experienced flu know how you don't always feel completely better as quickly as you've been hoping or expecting to."

The study also looked at other contributing factors, such as age and gender, to try to determine whether these factors contributed to a person's likelihood of developing long Covid.

Caller still hasn't received Covid test result on return to UK

When looking solely at Covid-19, the researchers found that different groups were affected by long-lasting symptoms in different ways.

For example, older people and men had more breathing difficulties and cognitive problems, whereas young people and women had more headaches, abdominal symptoms and anxiety or depression.

Patients admitted to hospital were more likely to suffer cognitive problems like brain fog and fatigue compared to people who did not need to be admitted, and people who did not need hospital care were more likely to have headaches than those who needed to be admitted.

When taking all factors into account, the research team estimated that 37 per cent of people who had a Covid-19 infection had at least one long Covid symptom three to six months after infection.

The Office for National Statistics estimates that 970,000 British people are suffering ongoing symptoms after a Covid-19 infection.

The figures, based on self-reported symptoms, also suggest 384,000 people are still living with symptoms a year after infection.

Separate ONS estimates, based on data from participants of the Coronavirus Infection Survey who had a lab-confirmed case of Covid-19, suggest that between 3 per cent and 12 per cent of people have symptoms 12 weeks after infection.

'It's all right not to know' everything about pandemic

The authors of today's study stressed there were "important caveats" which meant the results might not be generalised - namely that people included in the study with both flu and Covid could have been "iller" than most because they had sought medical help for their symptoms.

As a result the percentage of people suffering prolonged symptoms may not be representative of the general population.

Dr Taquet said: "Over one third of patients were diagnosed with at least one of the long Covid symptoms between three and six months after their Covid-19 illness.

"The severity of the illness, age and sex affected the incidence and profile of long Covid symptoms.

"Similar symptoms were seen in people after influenza but they occur and co-occur less commonly."

Health officials have warned that this year's flu season could be particularly troublesome as immunity to influenza viruses waned during the pandemic.

The Government is hoping that more people than ever will get their flu jab, with over-50s and clinically vulnerable people being called forward to get a vaccine.