Leicester-led review shows around one in three hospital infections involve antimicrobial resistance

With an estimated 1.14 million deaths worldwide annually caused by bacteria becoming resistant to antibiotics, a University of Leicester-led study shows that in hospital settings antimicrobial resistance is common and independently associated with a higher risk of death. 

The results were published in September 2025 in The Lancet’s eClinical Medicine.

Dr Daniel Pan, infectious diseases clinician, National Institute for Health and Care Research (NIHR) Doctoral Research Fellow at the University of Leicester, said. “Hospitals are high-risk environments for acquiring drug-resistant infections because many patients receive antibiotics and have invasive procedures.

“Even in settings where effective antibiotics should be available, resistant infections still carry an independent increase in the risk of dying. AMR doesn’t just threaten public health systems; it directly harms the individuals who acquire these infections.” 

Drawing on 34 hospital-based studies covering 20,658 patients across 18 countries, Dr Pan and the team found that over a third of hospital-acquired infections involved drug-resistant bacteria (pooled prevalence 36.5%). 

Patients with resistant infections had a 58% higher adjusted risk of death than those with susceptible infections, with the greatest risk seen for deaths during the same admission and for bloodstream infections. 

Senior author, Professor Manish Pareek, Chair in Infectious Diseases and Director of the Development Centre for Population Health at the University of Leicester, said: “Our analysis also highlights major evidence gaps: many under-represented regions, including parts of Africa, the Middle East and South Asia, had few or no eligible hospital-based studies linking AMR to mortality. If countries are to meet emerging UN goals on antibiotic access and reducing AMR, we urgently need better surveillance and studies from these regions.” 

This independent research was funded by Pacific Life Re and carried out with support from the NIHR Leicester Biomedical Research Centre (BRC). The views expressed are those of the authors and not necessarily those of the funders. 

Ian Collins, VP, Medical Analytics, Divisional at Pacific Life Re, added: “It was great to collaborate with the University of Leicester on this meta-analysis which shows there is a lot more that can be done to quantify the potential impact of AMR in the future. 

“This work has helped us to parameterise and calibrate our internal models and provides a great snapshot of the prevalence and lethality of resistive strains in hospital settings.”

The NIHR Leicester BRC is part of the NIHR and hosted by the University Hospitals of Leicester NHS Trust in partnership with the University of Leicester, Loughborough University and University Hospitals of Northamptonshire NHS Group.