Antimicrobial resistance (AMR) has been described as one of the world’s greatest threats to human and animal health. Some reports suggest that by 2050, AMR could kill around 10 million people each year worldwide. Public health leaders warn we could enter a ‘post-antibiotic’ era where easily treatable common infections become untreatable.
Some media coverage around AMR seems to scaremonger, and the predicted impact of AMR has been questioned. However, there is strong evidence that AMR is a growing problem and immediate action is needed. In fact, in September 2016, the United Nations hosted a high-level meeting of global leaders to discuss the situation – only the fourth time such a global forum had been used to discuss a health issue. In March of this year, the UN Secretary-General announced the establishment of an Interagency Coordination Group on Antimicrobial Resistance (ICG-AMR).
But what exactly is AMR? Why has it become such a problem and is there anything we can do as individuals or collectively to help these global efforts?
In our next three articles, we explain what antimicrobial resistance is, what we can do as individuals to be better stewards of antimicrobials and the impact of rapid diagnostics.
Part 1: What is antimicrobial resistance and why all the fuss?
The term ‘antimicrobials’ refers to antibiotics, antifungals, antivirals, anti-malarials and anthelmintics, i.e. anything used to treat or kill bacteria, fungi, viruses or parasites. Many antimicrobials are naturally occurring. In ancient times, various moulds, plants, sour milk and even frog bile were used to treat infections with little understanding of how or why they worked. Penicillin was the first widely used antibiotic in the 1940s. Since then, many more antimicrobials have been discovered and developed – including more than 100 different antibiotics licensed for use. In addition to treating infections, some compounds which were initially used as antibiotics are now more widely used as anti-cancer drugs.
The development of resistance to antimicrobials occurs naturally. Resistance develops when pathogens (the organisms causing disease) replicate their genetic code. Genetic code is not copied exactly – there are always random mistakes. Most of the mistakes (mutations) have no impact on the survival of the pathogen. But occasionally, mutations mean the antimicrobial can no longer kill the pathogen – it has become resistant. The pathogen will then survive to replicate and its offspring will have the same mutation, as will all subsequent generations originating from that pathogen. The speed at which resistance develops depends on many things. Some drugs only require a single mutation for resistance to develop, whilst others require multiple mutations to occur at the same time – which is a much rarer event. Some types of bacteria can pass resistant genes to other bacteria (horizontal gene transfer), not just their offspring, leading to the rapid spread of resistance.
Until recently, if resistance to one antimicrobial developed, other effective alternatives were available. However, we are now reaching the point at which we are running out of alternatives for some pathogens. Pathogens associated with epidemics in humans are multi-drug resistant, that is, they have resistance to more than one type of antimicrobial drug. Around 700,000 deaths occur each year from AMR infections worldwide. Drug resistance is already starting to complicate the fight against TB, HIV and malaria.
The speed at which AMR occurs varies by antimicrobial and pathogen. In addition, unnecessary use, incorrect dosing and incorrect duration of antimicrobial use by humans and food animals can accelerate the development of resistance. Although the development of resistance is inevitable when antimicrobials are being used, there are numerous ways in which we can slow down its development.
Dr. Susie Huntington