More than 1.2 million people died in 2019 from antibiotic-resistant bacterial infections, more deaths than HIV/Aids or malaria, a new study suggests.

The research indicates antimicrobial resistance (AMR) is now a leading cause of death worldwide, and the number could potentially be much higher.

It shows that many hundreds of thousands of deaths occur due to common, previously treatable infections – such as lower respiratory and bloodstream infections – because the bacteria that cause them have become resistant to treatment.

Study co-author Professor Chris Murray, of the Institute for Health Metrics and Evaluation at the University of Washington in America, said: “Previous estimates had predicted 10 million annual deaths from antimicrobial resistance by 2050, but we now know for certain that we are already far closer to that figure than we thought.

“We need to leverage this data to course-correct action and drive innovation if we want to stay ahead in the race against antimicrobial resistance.”

The paper, which includes an analysis of 204 countries and territories, outlines actions for policymakers that researchers say will help save lives and protect health systems.

The new Global Research on AntiMicrobial Resistance (GRAM) report estimates deaths linked to 23 pathogens and 88 pathogen-drug combinations.

Researchers used modelling to estimate the impact of AMR in all locations – including those with no data – and data from 471 million individual records.

For the purposes of the study, they estimated disease burden in two ways.

This included deaths directly caused by AMR, meaning they would not have occurred if the drugs had worked against the infection, therefore making them treatable.

Secondly they estimated deaths associated with AMR. This is where a drug-resistant infection was implicated in deaths, but resistance itself may or may not have been the direct cause.

According to the analysis, AMR was directly responsible for an estimated 1.27 million deaths worldwide, and associated with an estimated 4.95 million deaths, in 2019.

While HIV/Aids and malaria were estimated to have caused 860,000 and 640,000 deaths respectively in 2019.

The study, published in The Lancet, found that drug-resistance in lower respiratory infections – such as pneumonia – had the greatest impact on AMR disease burden.

It caused more than 400,000 deaths and was associated with more than 1.5 million deaths.

Drug resistance in bloodstream infections caused around 370,000 deaths and was associated with nearly 1.5 million deaths.

While drug resistance in intra-abdominal infections – commonly caused by appendicitis – led directly to around 210,000 deaths and was associated with around 800,000.

The data also suggests that young children were at particularly high risk, with around one in five deaths attributable to AMR occurring in children aged under five years.

Regionally, deaths caused directly by AMR were estimated to be highest in Sub-Saharan Africa and South Asia, at 24 deaths per 100,000 population and 22 deaths per 100,000 population respectively.

In high-income countries, AMR led directly to 13 deaths per 100,000 and was associated with 56 deaths per 100,000.

In the Western Europe region, which includes the UK, more than 51,000 people died as a direct result of AMR.

Of the 23 pathogens studied, drug resistance in six alone – including E. coli – led directly to 929,000 deaths and was associated with 3.57 million.

One pathogen-drug combination – methicillin-resistant S. aureus, or MRSA – directly caused more than 100,000 deaths in 2019.

Study co-author Christiane Dolecek, is GRAM scientific lead based in Oxford University’s Centre for Tropical Medicine and Global Health and the Mahidol Oxford Tropical Medicine Research Unit.

She said: “Being able to measure AMR, and compare it with other major health threats, is essential to addressing its serious consequences.”

Commenting on the need for political action on AMR, UK special envoy on antimicrobial resistance, Dame Sally Davies said: “AMR is already one of the greatest challenges facing humanity.

“Behind these new numbers are families and communities who are tragically bearing the brunt of the silent AMR pandemic.

“We must use this data as a warning signal to spur on action at every level.”

The researchers acknowledge a number of limitations to their study, including limited availability of data for some parts of the world.

This study was funded by the Bill & Melinda Gates Foundation, Wellcome Trust, and Department of Health and Social Care using UK aid funding managed by the Fleming Fund.