Press release: Doctors develop way to diagnose diarrhoea infection within an hour

FilmArray_2units_Doctors in Southampton have developed a pioneering way to test patients with diarrhoea that can diagnose the cause within an hour as opposed to the current wait of several days.

Researchers led by Dr Tristan Clark, a consultant in infectious diseases at University Hospital Southampton, believe it will revolutionise the management of patients coming to hospital with suspected gastroenteritis – an infection of the gut.

They also say it will remove “guesswork” around the need for antibiotic treatment or isolation in a single room. The GastroPOC trial has been running for two years and will conclude at the end of this winter.

Researchers are able to analyse stool samples at the bedside using a portable device to process the result, which is known as a point of care test (POCT).

There are up to 17 million cases of acute infectious diarrhoea in the UK every year and three million of these are attributed to norovirus, also known as the winter vomiting bug.

However, although diarrhoea can be caused by a virus, bacteria or parasites, it is not always a result of an infection and can develop due to a variety of other reasons, such as reactions to medications.

The current standard test used across the NHS to determine the cause of diarrhoea requires examination of patients’ stool samples in the laboratory and can take several days to report back.

“When a patient presents with diarrhoea the onus is on healthcare professionals to quickly determine its cause so patients with infections can be isolated to prevent them from infecting others and because they may require specific antibiotic treatment,” said Dr Clark (pictured).

“As the standard lab test can take up to several days, that means all patients with diarrhoea are required to be placed in a side room in case they have an infection and doctors also have to guess as to whether to treat with antibiotics or not.

“Neither of these processes are adequate because isolation rooms are in high demand - particularly in winter - and overuse or misuse of antibiotics is fuelling antimicrobial resistance.

CLARK Tristan

“This test, which is as accurate as the standard test, may offer an answer to these issues by providing a result in real-time.”

In the trial, funded by the University of Southampton and supported by BioFire Diagnostics LLC, participants are randomly assigned to one of two groups.

The stool samples of group one are tested immediately using the molecular POCT device and the others are performed in a laboratory using the current standard NHS method.

The medical records of all patients in the study will be reviewed to find out how long they were kept in single room isolation and what care they received during their stay in hospital. The results of the trial will be available at the end of 2020.

“At a time when antibiotic resistance poses a threat to modern medicine, any way we can reduce the number of unnecessary antibiotics being prescribed will be a significant advancement.

“Equally, this new testing method may allow more effective and efficient use of side rooms in hospital which, given the current pressures being faced nationwide, could significantly aid capacity management.”

The innovation is based on a similar model developed by Dr Clark in 2015 to rapidly diagnose influenza (flu) and other viral infections in patients with respiratory conditions which resulted in shorter courses of antibiotics and less time in hospital.

The results of a study using the test, published in the journal Lancet Respiratory Medicine, 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 influenza 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.

Posted on Friday 29 November 2019