Move over long COVID, 'long colds' are a thing, too

A new study has found that people with non-COVID respiratory infections such as colds, flu, and pneumonia can suffer from ‘long’ symptoms that persist well beyond the acute infection stage. The findings increase awareness about the existence of long-lasting respiratory infections other than long COVID.

We’ve all heard of long COVID, where the signs and symptoms of COVID-19 persist for more than four weeks after the acute infection. Now, a new study by researchers at the Queen Mary University of London has found that ‘long’ versions of non-COVID respiratory infections also exist.

The researchers asked 10,171 UK adults to report 16 symptoms commonly found in long COVID, such as fatigue, breathlessness, aches and pains, and dizziness. They then compared how common these symptoms were among three groups: people who’d reported COVID, those who’d reported another acute respiratory infection (ARI) but tested negative for COVID, and those who’d reported neither.

They focused on long-term symptoms only by including people who’d been infected with COVID or another ARI more than four weeks earlier and took into account their general health prior to infection and whether they had existing lung conditions.

“Our study showed that all the symptoms considered were more common in people with previous COVID than in people with no infections, regardless of whether they reported long COVID,” said Giulia Vivaldi, lead and corresponding author of the study. “But this finding wasn’t unique to COVID. Almost all the symptoms we looked at were also more common in people with non-COVID respiratory infections than in those with no infection.”

The researchers say their findings suggest that the post-acute symptoms of non-COVID ARIs may not be being picked up by health professionals.

“In other words, our findings hinted towards the existence of a ‘long cold’: long-lasting health effects from other respiratory infections, such as cold, flu, or pneumonia, that are currently going unrecognized,” Vivaldi said.

Some of the most common symptoms of the long cold included coughing, stomach pain, and diarrhea, reported by study participants on average 11 weeks after the initial infection. While the researchers didn’t find evidence that long cold symptoms have the same severity or duration as long COVID symptoms like loss of taste and smell, they say the study sheds light on other ‘long’ respiratory conditions.

“A lack of awareness, or even the lack of a common term, such as ‘long cold’ or ‘long flu’, prevents both reporting and diagnosis of these conditions,” said Vivaldi. “And people who do report their long cold may still struggle to get a diagnosis, owing to the wide range of symptoms and lack of diagnostic tests.”

Back in February 2023, it was reported that, post-coronavirus pandemic, there’d been a rise in Strep A, flu, and respiratory syncytial virus (RSV) infections. More recently, there have been reports of a rise in human metapneumovirus (HMPV) infections in the US and Australia. Some studies have suggested that pandemic-related interventions like social distancing and isolation significantly altered the seasonal patterns of some viruses, which led to a rise in infections when these interventions were removed.

The researchers say that the focus on long COVID has opened the door to a better understanding of the long-term effects of other ARIs, which is a good thing.

“In demanding recognition of their condition, people with long COVID have case a much-needed spotlight on post-infection syndromes more generally,” Vivaldi said. “Now is the time to improve our understanding, diagnosis and treatment of these conditions. Let’s not wait for another pandemic.”

The study was published in the journal eClinical Medicine.

Source: Queen Mary University of London