Researchers in London have suggested that long colds do, in fact, exist and are just as common as long Covid, with their study showing that 22% of people with Covid suffered prolonged symptoms after infection, as did 22% of those who had an infection that was not Covid.
During the pandemic, a small percentage of people infected with Covid-19 went on to suffer prolonged issues for several months, often after the virus had been cleared. Currently, fatigue, brain fog, loss of smell and taste, coughs and other symptoms are still reported by more than 1m people in the UK after having Covid.
The researchers, from Queen Mary University of London, found people who experience long-term symptoms – or long colds – after respiratory infections that test negative for Covid, reports The Telegraph.
Some of the most common symptoms of long colds were coughing, stomach pain and diarrhoea lasting for more than four weeks after infection.
“Our findings suggest that there may be long-lasting health impacts from other respiratory infections that are going unrecognised,” the researchers said.
Viruses causing infections can persist
Study author Professor Adrian Martineau said there was a “similar risk of prolonged symptoms” from Covid or other infections.
While data show Covid infections were more likely to cause taste and smell problems, light-headedness, dizziness, sweating and hair loss than those with a “long cold”, the latter was more likely to manifest as a cough or a hoarse voice. Both groups suffered breathlessness and fatigue.
The study also suggested that a person was more likely to suffer a long-term health decline if the initial bout of infection were more severe.
However, the experts said more studies were needed on why some people suffer while others do not.
“Our findings shine a light not only on the impact of long Covid on people’s lives, but also other respiratory infections,” Giulia Vivaldi, lead author, said.
“A lack of awareness – or even the lack of a common term – prevents both reporting and diagnosis of these conditions.
“As research into long Covid continues, we need to take the opportunity to investigate and consider the lasting effects of other acute respiratory infections.”
Still sick months later
The study looked at people’s symptoms – after their initial infection – using standardised questionnaires, and found they were still sick several months later.
One non-Covid long cold case reported having symptoms one year and three months after infection.
Martineau added: “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.
“Ongoing research into the long-term effects of Covid 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.”
Dr David Strain, clinical senior lecturer and honorary consultant at the University of Exeter, welcomed the study, adding the researchers had “demonstrated, at least in the short term, persistence of symptoms can be troubling not just after Covid but after many other infections”.
He said this was not a new phenomenon, citing the Spanish flu epidemic in 1918-20 as leaving many people with post-viral illness.
He said the research would bring into focus the “urgent need for further research into post-viral syndromes”, what causes them and the need for treatments.
The study is published in The Lancet’s eClinicalMedicine journal.
Study details
Long-term symptom profiles after COVID-19 vs other acute respiratory infections: an analysis of data from the COVIDENCE UK study
Giulia Vivaldi, Paul E. Pfeffer, Adrian Martineau, et al.
Published in The Lancet eClinical Medicine on 6 October 2023
Summary
Background
Long Covid is a well recognised, if heterogeneous, entity. Acute respiratory infections (ARIs) due to other pathogens may cause long-term symptoms, but few studies compare post-acute sequelae between SARS-CoV-2 and other ARIs. We aimed to compare symptom profiles between people with previous SARS-CoV-2 infection, people with previous non-Covid-19 ARIs, and contemporaneous controls, and to identify clusters of long-term symptoms.
Methods
COVIDENCE UK is a prospective, population-based UK study of ARIs in adults. We analysed data for 16 potential long Covid symptoms and health-related quality of life (HRQoL), reported between January 21 and February 15, 2021, by participants unvaccinated against SARS-CoV-2. We classified participants as having previous SARS-CoV-2 infection or previous non-Covid-19 ARI (≥4 weeks prior) or no reported ARI. We compared symptoms by infection status using logistic and fractional regression, and identified symptom clusters using latent class analysis (LCA).
Findings
We included 10,171 participants (1311 [12.9%] with SARS-CoV-2 infection, 472 [4.6%] with non-Covid-19 ARI). Both types of infection were associated with increased prevalence/severity of most symptoms and decreased HRQoL compared with no infection. Participants with SARS-CoV-2 infection had increased odds of problems with taste/smell (odds ratio 19.74, 95% CI 10.53–37.00) and light-headedness or dizziness (1.74, 1.18–2.56) compared with participants with non-Covid-19 ARIs. Separate LCA models identified three symptom severity groups for each infection type. In the most severe groups (representing 22% of participants for both SARS-CoV-2 and non-Covid-19 ARI), SARS-CoV-2 infection presented with a higher probability of problems with taste/smell (probability 0.41 vs 0.04), hair loss (0.25 vs 0.16), unusual sweating (0.38 vs 0.25), unusual racing of the heart (0.43 vs 0.33), and memory problems (0.70 vs 0.55) than non-Covid-19 ARI.
Interpretation
Both SARS-CoV-2 and non-Covid-19 ARIs are associated with a wide range of symptoms more than 4 weeks after the acute infection. Research on post-acute sequelae of ARIs should extend from SARS-CoV-2 to include other pathogens.
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