A research team from the Infection, Immunity and Cancer theme is undertaking a pioneering Victoria-based trial of two new tests for bacterial infection that have the potential to significantly reduce the overuse of antibiotics to treat common respiratory illnesses.
Overuse of antibiotics and associated antimicrobial resistance is rising globally
Australia is one of the highest antibiotic prescribing countries in the developed world. According to Deakin University research fellow Dr Sajal Saha, 30 to 50 per cent of antibiotic prescriptions are deemed unnecessary in the community, particularly in respiratory tract infections.
“The unnecessary use of antibiotics – which could involve taking them when not needed, taking them for longer than required or taking an incorrect dose – causes antibiotics to become ineffective over time, a phenomenon called antimicrobial resistance (AMR),” he explained.
“A typical test for bacterial infection currently takes a few days to produce a result, so often when a patient presents with respiratory symptoms to a medical practitioner, antibiotics will be prescribed without knowing exactly whether the infection is viral or bacterial and how severe the infection is.”
Dr Saha said around 60 to 70 per cent of sore throat infections in the community are viral and therefore don’t need an antibiotic, but because of the uncertainty and demands on GPs, they tend to err on the side of prescribing.
“The more someone uses antibiotics unnecessarily, the more opportunities you are giving the bacteria to change their structure and hide so the antibiotic can’t find them,” Dr Saha said.
AMR is making infections harder to treat and increasing the risk of disease, severe illness and deaths around the world. According to the World Health Organisation, AMR contributed to 1.27 million deaths globally in 2019 and is estimated to result in up to 10 million deaths each year by 2050.
Australia-first trial aims to give doctors more certainty when prescribing antibiotics
The Infection, Immunity and Cancer theme is running a trial which aims to help clinicians more accurately diagnose the cause of infection and allow for better targeted treatment, potentially reducing the problem of over prescription of antibiotics in Australia and across the world.
Taking place across several GP clinics in Geelong and Melbourne, the two point-of-care tests involve a simple finger prick or throat swab.
Both tests produce a result within minutes, allowing the GP to establish whether a patient’s infection is bacterial, and requires antibiotics, or viral, and requires alternative treatment.
The throat swab detects Strep A bacteria – which causes an acute sore throat including tonsillitis or pharyngitis – while the finger prick (C-reactive protein testing) is mostly used to diagnose respiratory tract infections and judge how likely the infection is bacterial.
“Our research is trying to support general practitioners to overcome diagnostic uncertainty,” Dr Saha said. “The trials have the potential to significantly improve the safe use of antibiotics because within two to three minutes, you get to know the results. At the moment, the standard C-Reactive Protein test which is used takes 24 to 48 hours.
“So far it has proved to be a simple test and early results from five GP clinics in Geelong show it can reduce antibiotic use by up to 30 per cent.” Dr Saha said.
The feasibility trial – which assessed these tests on a smaller scale – is now complete.
A larger pilot trial beginning in May 2025 will be rolled out across regional and rural settings until October, after which researchers will analyse the results.
Dr Saha said the tests were likely to benefit urgent care centres and larger clinics the most, where there is a higher volume of patients.
Shifting community perspectives on antibiotics
The trial also seeks to alter public awareness when it comes to antibiotic use. Dr Saha said there is a strong perception in the community right now that getting an antibiotic will cure an infection, regardless of whether it’s viral or bacterial. With on-the-spot testing, a doctor can tell the patient how severe the infection actually is, which could change the patient’s attitude towards the need for antibiotics.
