Scientists say they have found evidence that people may experience “long colds”, acute respiratory infections with long-term symptoms.
Some of the most common symptoms include coughing, stomach pain, and diarrhoea more than four weeks after the initial infection. The severity of an illness appears to be a key driver of risk of long-term symptoms.
The study, led by Queen Mary University of London (QMUL), was published in the Lancet’s EClinicalMedicine journal.
The findings suggest there may be long-lasting health impacts after non-Covid acute respiratory infections such as colds, influenza, or pneumonia, that have been going unrecognised.
However, the researchers do not yet have evidence suggesting that the symptoms have the same severity or duration as long Covid.
Prof Adrian Martineau, a clinical professor of respiratory infection and immunity at QMUL, said: “Our findings may chime with the experience of people who have struggled with prolonged symptoms after having a respiratory infection despite testing negative for Covid-19 on a nose or throat swab.
“Ongoing research into the long-term effects of Covid-19 and other acute respiratory infections is important because it can help us to get to the root of why some people experience more prolonged symptoms than others. Ultimately this could help us to identify the most appropriate form of treatment and care for affected people.”
Researchers found that people experience long-term symptoms – or long colds – after respiratory infections that test negative for Covid-19. Their findings suggests some – though not all – people may suffer long-term effects from colds, flu or pneumonia.
Experts looked at data from 10,203 people taking part in the Covidence UK study into coronavirus in the population. At the time of this analysis, 1,343 had suffered a Covid infection and 472 had had a respiratory infection that tested negative for Covid.
The results showed that 22% of people with Covid-19 suffered prolonged symptoms after infection, as did 22% of those who had an infection that was not Covid, Martineau said.
There was a “similar risk of prolonged symptoms” irrespective of whether it was caused by Covid or non-Covid infection, he added.
Martineau said people with Covid in the study were more likely to suffer taste and smell problems and light-headedness or dizziness than those without. They also suffered heart palpitations, sweating and hair loss.
Those in the non-Covid group were more likely to have a cough or a hoarse voice than people with Covid. Both groups suffered breathlessness and fatigue.
The more serious a bout of illness, the greater the chance of having long-term symptoms, the study found. However, the researchers said more research was needed to understand why some people suffer while others do not.
Dr David Strain, a clinical senior lecturer and honorary consultant at the University of Exeter, who was not involved in the study, welcomed its findings. The researchers had “demonstrated, at least in the short term, persistence of symptoms can be troubling not just after Covid-19 but after many other infections”, he said.
