Antibiotic drugs used in four European countries against five priority pathogens, including ‘superbug’ MRSA, are likely to remain effective well into the next decade, a study suggests.
The study, published in the journal PLOS One, compared projections by experts with statistical forecasts to predict resistance rates of common pathogen-antibiotic pairs to 2026.
Experts in microbiology, epidemiology and public health from France, Spain and the UK forecast that resistance rates for five pathogen-antibiotic pairs on the World Health Organization’s priority list would remain below 50% in their respective countries.
Italy is likely remain below 50% resistance for all pairs except one which has already exceeded 50%. For that pair, the experts thought the country would sustain or see an improvement its current rates of resistance.
The experts’ judgements were based on their belief that a local, national and global focus on antibiotic stewardship and infection control will continue to positively impact resistance rates.
The five priority pathogen-antibiotic pairs discussed in the research paper were: E. coli and third-generation cephalosporins; E. coli and carbapenems; Klebsiella pneumoniae and third generation cephalosporins; K. pneumoniae and carbapenems; and Staphylococcus aureus and methicillin (MRSA).
Lead researcher Dr Abigail Colson, from the Department of Management Science at the University of Strathclyde, said: “The increase in multidrug resistance to last-line antibiotics is a major global public health threat.
“In our study we used the Classical Model of structured expert judgement to elicit projections of resistance rates of pathogen-antibiotics pairs through to 2026 in four European countries.
The results from our experts indicate most of the antibiotics studied will likely remain effective in the next decade for treating the majority of infections caused by the pathogens discussed in France, Italy, Spain, and the United Kingdom.
“This result may not hold for all countries, especially mid-income countries like Brazil, India, and China which have recently seen the largest increases in antibiotic consumption.”
The European Centre for Disease Prevention and Control estimates that antibiotic-resistant pathogens cause more than 25,000 deaths in Europe annually.
Predicting antibiotic resistance is difficult due to a lack of research and the report’s authors highlight the shortcomings of various predictive models.
Historical data-based projections assume fixed antibiotic consumption and are not updated, while mathematical models are challenged by the large number of interacting factors – for example, doctors countering an observed rise in resistance by prescribing fewer antibiotics thus affecting future resistance rates.
Similarly, statistical forecasting methods also struggle to anticipate and process fundamental changes to the environment, such as infection control, reduced antibiotic use or new drugs on the market.
Expert forecasting, however, makes use of extensive knowledge about these issues relevant to thinking about the future trajectory of resistance and its uncertainty.
While expert judgement can be subject to a range of biases, a technique called ‘expert elicitation’ enables experts to provide estimates and quantify their uncertainty in a way that minimises bias.
The Classical Model of structured expert judgement used in this study was validated against empirical data and has been well-used in over 80 applications.
Although, in many cases, the expert results differed to the statistical forecasts, based on historical data from the European Antimicrobial Resistance Surveillance Network, the researchers say the judgemental forecasts include information about the impact of current and future shifts in infection control, antibiotic usage and other factors that cannot easily be captured in statistical forecasts.
They claim the study demonstrates the potential of structured expert judgement as a tool for better understanding of the uncertainty about future antibiotic resistance.
Dr Colson said: “Surveillance programmes provide useful current and historical information on the scale of the problem, but the future emergence of antibiotic resistance is uncertain.
“Researchers in this area don’t currently know enough to build models that can accurately project resistance rates, but experts do have enough to make informed judgements.
Our paper demonstrates the potential of structured expert judgement as a tool for better understanding the uncertainty about future antibiotic resistance.”
The researchers identified experts from fields including microbiology, epidemiology, public health and clinical infectious diseases and ask them for their views. All of the experts were recruited from government, health systems and academia.
The study also involved researchers from the Center for Disease Dynamics, Economics & Policy, Washington DC; the Department of Infectious Diseases, Rural Development Trust Hospital, Bathaliapalli, India; Resources for the Future, Washington DC; TU Delft, The Netherlands; and Princeton Environmental Institute, Princeton University, New Jersey.
The research was supported by the Innovative Medicines Initiative Joint Undertaking under the Driving re-investment in R&D and responsible antibiotic use (DRIVE-AB) funded by the European Union’s Seventh Framework Programme and European Federation of Pharmaceutical Industries and Associations companies’ in-kind contributions.