Doctors and researchers at the University of Southampton have developed a novel way of using a swab test which can rapidly diagnose flu and other viral infections in patients with severe respiratory conditions – resulting in shorter courses of antibiotics and less time in hospital.
Developed by Dr Tristan Clark, an associate professor in infectious diseases at the University of Southampton and colleagues at the NIHR Southampton Biomedical Research Centre, the 'point-of-care' testing strategy can be carried out in hospital emergency departments and acute medical units.
It involves processing swabs immediately on a portable device combined with a rapid molecular test and, as samples do not need to be sent to the laboratory, results can be delivered within an hour as opposed to a number of days.
The system was trialled in a study at UHS during the winters of 2015 and 2016 which involved 720 patients with acute respiratory illness, including pneumonia and exacerbations of asthma and chronic obstructive pulmonary disease (COPD).
Half the patients had the point-of-care test, in which case a swab was analysed on the device and the results given to their treating doctor, while the other half received standard care.
Results showed patients who had the point-of-care test got the right treatment for their lung condition faster. In addition, patients who tested positive for flu in the point-of-care testing group were appropriately isolated in a side room and given antiviral medication more often and sooner than those in the standard care group.
"My vision is that anyone who comes into hospital with an acute respiratory condition will receive this point-of-care test as soon as they come through the hospital door," explained Clark, a consultant in infectious diseases at University Hospital Southampton NHS Foundation Trust.
"It tells us immediately what virus the person has so, for example, if they have flu they can be isolated in a side room and given antiviral drugs without delay."
Clark also highlighted the potential of the test to tackle antibiotic resistance – the growth of resistant strains of bacteria which cannot be treated with antibiotics – by reducing unnecessary or ineffective use of medication. "Lung infections in asthma and COPD patients are a common cause of antibiotic overuse" he said.
"Antibiotics are only effective at treating bacterial infections and not infections caused by a virus like the cold or flu viruses, yet they are often given antibiotics 'just in case', when the cause of the infection is not immediately apparent."
He added: "Tests like this, which enable tailored and personalised medicine, have a major role to play in the fight against antibiotic resistance."
The point-of-care test came to prominence during the winter of 2015 when, during the study, doctors at Southampton General Hospital found a large proportion of patients attending hospital with respiratory illnesses were suffering from a strain of influenza not covered by the seasonal flu vaccine.
Summary
Background: Respiratory virus infection is a common cause of hospitalisation in adults. Rapid point-of-care testing (POCT) for respiratory viruses might improve clinical care by reducing unnecessary antibiotic use, shortening length of hospital stay, improving influenza detection and treatment, and rationalising isolation facility use; however, insufficient evidence exists to support its use over standard clinical care. We aimed to assess the effect of routine POCT on a broad range of clinical outcomes including antibiotic use.
Methods: In this pragmatic, parallel-group, open-label, randomised controlled trial, we enrolled adults (aged ≥18 years) within 24 h of presenting to the emergency department or acute medical unit of a large UK hospital with acute respiratory illness or fever higher than 37·5°C (≤7 days duration), or both, over two winter seasons. Patients were randomly assigned (1:1), via an internet-based allocation sequence with random permuted blocks, to have a molecular POC test for respiratory viruses or routine clinical care. The primary outcome was the proportion of patients who received antibiotics while hospitalised (up to 30 days). Secondary outcomes included duration of antibiotics, proportion of patients receiving single doses or brief courses of antibiotics, length of stay, antiviral use, isolation facility use, and safety. Analysis was by modified intention to treat, excluding patients who declined intervention or were withdrawn for protocol violations. This study is registered with ISRCTN, number 90211642, and has been completed.
Findings: Between Jan 15, 2015, and April 30, 2015, and between Oct 1, 2015, and April 30, 2016, we enrolled 720 patients (362 assigned to POCT and 358 to routine care). Six patients withdrew or had protocol violations. 301 (84%) of 360 patients in the POCT group received antibiotics compared with 294 (83%) of 354 controls (difference 0·6%, 95% CI −4·9 to 6·0; p=0·84). Mean duration of antibiotics did not differ between groups (7·2 days [SD 5·1] in the POCT group vs 7·7 days [4·9] in the control group; difference −0·4, 95% CI −1·2 to 0·4; p=0·32). 50 (17%) of 301 patients treated with antibiotics in the POCT group received single doses or brief courses of antibiotics ( Interpretation: Routine use of molecular POCT for respiratory viruses did not reduce the proportion of patients treated with antibiotics. However, the primary outcome measure failed to capture differences in antibiotic use because many patients were started on antibiotics before the results of POCT could be made available. Although POCT was not associated with a reduction in the duration of antibiotics overall, more patients in the POCT group received single doses or brief courses of antibiotics than did patients in the control group. POCT was also associated with a reduced length of stay and improved influenza detection and antiviral use, and appeared to be safe.
Authors
Nathan J Brendish, Ahalya K Malachira, Lawrence Armstrong, Rebecca Houghton, Sandra Aitken, Esther Nyimbili, Sean Ewings, Patrick J Lillie, Tristan W Clark
[link url="https://www.sciencedaily.com/releases/2017/04/170406152406.htm"]University of Southamptom material[/link]
[link url="http://www.thelancet.com/journals/lanres/article/PIIS2213-2600(17)30120-0/abstract"]The Lancet Respiratory Medicine article summary[/link]