Impact of ‘long colds’ after non-Covid ARIs may be underestimated, study suggests

12th October 2023

‘Long colds’ with similar respiratory impact as long Covid may be an ‘underestimated’ issue, a new study has concluded.

By analysing 16 potential long Covid symptoms in participants from a UK population-based study, researchers found that a previous Covid infection was ‘associated with increased prevalence and severity of a wide range of symptoms’.

In particular, participants with a previous Covid infection had increased odds of problems with taste or smell and lightheadedness or dizziness compared with participants who had previous non-Covid acute respiratory infections (ARIs).

However, they also found ‘increased burden of many symptoms’ among those who had non-Covid ARIs when compared with those who had no previous infections. 

The authors therefore suggested there could be ‘long-lasting health impacts from other respiratory infections that are going unrecognised’.

Using the COVIDENCE UK study, the researchers looked at data reported between January and February 2021 by over 10,000 participants who were unvaccinated against Covid. 

Their findings said: ‘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 lightheadedness or dizziness (1.74, 1.18–2.56) compared with participants with non-Covid-19 ARIs.’

But for other symptoms, there was ‘little difference’ between those with previous Covid infections and those with other infections. 

While the researchers suggested that long-term symptoms following ARIs could be similar to long Covid, they highlighted that their study does not show whether these symptoms have a similar duration. 

The findings also indicated that coughing, problems with taste or smell and dyspnoea may be the first symptoms to show improvement following a Covid infection, since there was a lower symptom burden among participants who had been infected more than 12 weeks prior. 

Both long Covid and post-ARI symptoms are likely under-reported, and, for the latter, an ‘alternative diagnosis’ may be needed, according to the authors.

They said: ‘Importantly, less than a quarter of our participants with previous SARS-CoV-2 infection had ever reported long Covid – including half of participants with the most severe symptoms – suggesting that some people with ongoing symptoms may not be ascribing these symptoms to the infection, or may not consider their symptoms serious enough to qualify as long Covid.

‘This could exacerbate under-reporting of the condition, likely impacting the healthcare resources made available to people with long-term sequelae.

‘A lack of awareness of post-acute sequelae of other ARIs – or even the lack of a common term, like “long Covid” – is likely to contribute to under-reporting as well.’

The authors highlighted the need for future research to enable diagnosis of both long Covid and other post-ARI symptoms so that all patients get the support they need.

Professor Paul Harrison, professor of psychiatry at the University of Oxford, said the study ‘supports previous findings that long-term symptoms are common after respiratory infections in general’ and not just after Covid.

He added: ‘However, Covid-19 infection was associated with a higher risk of several complaints, including memory problems, suggesting that ‘brain fog’ may be particularly related to the SARS-CoV-2 virus.’ 

Professor Peter Openshaw, professor of experimental medicine at Imperial College London, said: ‘The study is important in showing that recovery from ARI may be slow regardless of cause, that people should expect a slow return to normality and not expect to immediately return to full activities immediately after an ARI from whatever cause.  

‘The study does not show how many of those suffering from ARI go on to develop longer term debility.’

This story was originally published by our sister publication Pulse.

Point-of-care test identifies bacterial and viral causes of acute respiratory infections

27th October 2022

A point-of-care test shows good sensitivity for identifying both bacterial and viral pathogens in patients with acute respiratory infections

A point-of-care test has been found to correctly distinguish between bacterial and viral infections based on the host’s immune response, among patients with acute respiratory infections according to the results of a diagnostic study by team of US researchers.

Respiratory symptoms are the motive for a third of emergency room visits by both adult and paediatric patients. Acute respiratory infections due to either acute bronchitis, sinusitis, pneumonia and the common cold often present with overlapping symptoms leading to over-prescribing of antibiotics. Although multiplex PCR systems are available for the identification of bacterial and viral pathogens, an alternative strategy is to use a point-of-care test based on the host’s immune response to myxovirus resistance protein A (MxA) and C-reactive protein (CRP) in a finger-stick whole blood sample. To test the value of this approach in helping clinicians to decide on whether or not to prescribed antibiotics, in the present study, the US team examined the ability of the FebriDx^® which is a rapid, point-of-care diagnostic test that is designed to aid in the differentiation of bacterial and viral acute respiratory infections. The test can provide a result within 10 minutes by identifying myxovirus resistance protein A, which is induced by type 1 interferon due to viral infections and CRP, a non-specific acute-phase protein produced in response to inflammation and infection. While CRP is not specific for bacterial infections, if only MxA levels are elevated (i.e., no change in CRP) this is indicative of a viral infection. Similarly, elevated CRP in the absence of MxA, indicates a bacterial infection.

The US team recruited patients from emergency departments and outpatient settings who presented with new-onset respiratory symptoms including rhinorrhoea, nasal congestion, sore, throat, hoarseness, cough or shortness of breath and a recent fever and an asymptomatic control group. The point-of-care test was administered to both groups of patients although the treating physicians were blind to the test results. The primary outcome was set as a bacterial or viral-associated systemic host response. In addition, patient samples were collected and analysed by multiplex PCR for either viral or bacterial identification and which served as independent assessment of the point-of-care test result.

Point-of-care test and bacterial or viral identification

A total of 520 symptomatic patients with a mean age of 35.3 (44.2% male) were included and 170 in the asymptomatic group.

Final diagnostic information was available for 496 individuals and of whom, 14.7% had a confirmed bacterial and 59.7% a viral infection with the remainder classed as negative. The point-of-care test correctly identified 93.1% of bacterial infections giving a sensitivity of 93.2% (95% CI 84.9 – 97%), a specificity of 88.4% (95% CI 85 – 91.1%) and a positive predictive value of 58.1%.

For viral infections, the point-of-care test had a sensitivity of 70.3% (95% CI 64.8 – 75.2%), a specificity of 88% (95% CI 82.8 – 91.8%) and a positive predictive value of 89.7%. Interestingly, none of the participants had a co-infection which was defined as both a bacterial and viral pathogen plus a host response based on the independent assessment.

The authors concluded that the rapid diagnostic point-of-care test could help inform clinicians when assessing for either bacterial or viral causes for acute respiratory infections.

Citation
Shapiro NI et al. Diagnostic Accuracy of a Bacterial and Viral Biomarker Point-of-Care Test in the Outpatient Setting JAMA Netw Open 2022