Oxford researcher explores new way to reduce antibiotic overuse in Bangladesh

Oxford DPhil Forhad Chowdhury has shared the results of his recent study and knowledge exchange workshop to help clinicians in Bangladesh decide when to reduce antibiotic levels during treatment. 

Widespread overuse and misuse of antibiotics have contributed to a global rise in antimicrobial resistance (AMR), making infectious diseases harder to treat. Low- and middle- income countries (LMICs) face a far heavier burden, with 1 in 3 reported infections in South Asia and the Middle East displaying antibiotic resistance.

Forhad Chowdhury, DPhil student at Oxford’s Nuffield Department of Medicine, has seen first-hand the impact antibiotic resistant infections can have on patients, when he worked as a clinician in Bangladesh. He also saw that antibiotics in Bangladesh were available for patients to buy over-the counter, and that clinicians showed tendencies to over-prescribe antibiotics due to a lack of microbiological tests - leading to a culture of antibiotic over-use.

Microbiological tests are crucial to help clinicians determine the most appropriate course and length of antibiotic treatment. They allow clinicians to rapidly detect the presence of bacteria in blood and urine samples from patients.

However, high-quality microbiology labs are not always accessible in low-and-middle income countries like Bangladesh. Instead, clinicians rely on standardised national guidelines. These recommend predefined durations for using specific antibiotics, which don't vary patient-to-patient and can lead to patients taking the drug for longer than strictly necessary.

The PROCALBAN study: a new way to test for infections

For his DPhil, Forhad studied other, non-microbiological forms of testing, which can inform the de-escalation of antibiotic treatments without involving the lab. He chose to use a compound called procalcitonin, which becomes more prevalent in the body when there is a bacterial infection, and decreases after treatment with antibiotics. 

Starting in 2023, Forhad and a team of researchers ran the PROCALBAN clinical trial to assess the efficacy and safety of procalcitonin as a biomarker to guide antibiotic use. They recruited over 500 patients with either confirmed or suspected sepsis in the Chittagong Medical College in Bangladesh.

Patients were split into two groups: one group where antibiotic treatment duration was guided by daily procalcitonin tests through, and another where treatment was guided solely by national guidelines.

Forhad and the team found that, on average, treatment duration could be shortened by around 3 days - enough of a reduction to significantly reduce antibiotic overuse in the region.

The team also sent 120 bacterial isolates to the UK for whole genome sequencing, which will fuel further research into sepsis in low-and-middle income countries, and provide site-specific genetic data on the burden of AMR in Bangladesh. 

Research collaboration with the AMR Knowledge Exchange grant

One key challenge Forhad faced during the clinical trial was a lack of desire to stop treatments early. Because of this, the team spent a lot of time on advocacy and outreach, showcasing both the potential of their tests to stop antibiotic overuse, and the potential harms of encouraging AMR development.

Over time, clinicians and patients became used to the procalcitonin tests, with many in the hospital accepting them as a useful diagnostic tool by the trial conclusion. After seeing the huge potential improvements their tests can create, Forhad’s goal now is to encourage even more widespread acceptance among clinicians in Bangladesh.

To achieve this, Forhad was granted the IOI Knowledge Exchange Fund to travel back to Bangladesh, where he shared his findings with researchers, clincians, educators and trainees through an in-person dissemination meeting. This meeting gave Forhad a chance to communicate the impacts and benefits of procalcitonin tests on everyday hospital decision making, and gave staff the opportunity to ask practical questions about cost-effectiveness, availability and how the tests would fit into hospital workflow.

After completing his DPhil, Forhad intends to continue researching ways to reduce the AMR burden in Bangladesh, creating a research team to investigate other novel techniques like the procalcitonin tests, and inspiring other researchers to do the same.

Forhad Chowdhury said, “By prolonging the use of antibiotics in patients without biological indication or validation, patients and clinicians were overusing antibiotics, which increases the spread of AMR. The necessary microbiological tests to guide these treatments can often be unavailable to clinicians in resource-limited settings, so in my research I wanted to show that there are viable alternatives.”

He further said, “High levels of the biomarker procalcitonin in blood samples indicate an infection, and when antibiotic treatments cause levels to drop below a pre-determined safe target amount, a patient no longer needs antibiotics. Procalcitonin-based diagnostics can provide a more affordable, accessible way of testing for infections than sending samples to labs, ultimately reducing the burden of prolonged antibiotic use in hospitals in Bangladesh.”

Source: Ineos Oxford Institute