Microbes resistant to antimicrobials are winning the evolutionary war, writes Simar Mann.
Like the Borg in Star Trek, microbes are constantly evolving to get past their host’s defences (thankfully they don’t tend to assimilate their hosts into a hive mind). They are becoming resistant to the drugs created to prevent diseases caused by them, and this tactic is far from futile.
A recent study in The Lancet estimated that, in 2019, antimicrobial resistance (AMR) led to 4.95 million deaths, 1.27 million of which were directly caused by drug-resistant bacteria. In fact, we are once again nearing the time when an infection in a small injury could become life-threatening, and it is time we step up to this challenge before it is too late.
Antimicrobials are an indispensable part of global healthcare and have saved millions of lives, but resistance has always been on the horizon. Upon receiving his Nobel Prize in 1945 for discovering penicillin, Sir Alexander Fleming himself warned of “the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant.”
Sadly, his words were all too accurate. By the late 1940s, Staphylococcus aureus (a bacteria that causes skin infections and pneumonia) had already found its way past antimicrobials and was on its way to causing millions of deaths.
“Superbugs” – bacteria that are resistant to not just one, but several drugs – emerged as antimicrobials became more widely used.
The highly infectious Mycobacterium tuberculosis is probably the best-known example: in 2020, tuberculosis was responsible for 1.5 million deaths worldwide.
However, you are far more likely to experience the effects of Neisseria gonorrhoeae. This particular superbug causes a sexually transmitted infection (gonorrhea) which the World Health Organisation (WHO) estimates infects over 200,000 people every day, and half of these infections are caused by antimicrobial-resistant strains.
Overuse and misuse are exacerbating the problem. This is particularly the case in low- to middle-income countries where antimicrobials are easily available as over-the-counter medications.
Surveys estimate almost all antimicrobials in Nigeria and Sudan are taken without a prescription, compared to around half in Brazil and just 3% in Northern Europe. While people prefer self-medication to avoid visiting a doctor, the danger is that without professional oversight these drugs are taken unnecessarily or courses are left unfinished, thus giving microbes additional opportunities to develop resistance.
The extensive use of antimicrobials in livestock further increases AMR. A report published by the US Food and Drug Administration (FDA) revealed that 70% of medically important antimicrobials are used for animal husbandry. This is to avoid diseases being passed along the food chain, but many animals are also given antimicrobials to promote growth and prevent infections.
In the European Union, the use of antimicrobials as growth promoters is banned. This reduces the amount of antimicrobials consumed unintentionally in meat and is a good first step that other countries could follow.
Other initiatives to overcome the challenge of AMR are being undertaken at regional and global levels. For a start, the Covid-19 pandemic may have a silver lining in the increased focus it has placed on clean water, sanitation, and hygiene. This awareness will help to slow many infectious diseases and, in turn, reduce the amount of antimicrobial usage.
Most importantly, though, we must raise awareness in communities and among health professionals and policy makers globally to prevent the misuse of antimicrobials. For this reason, the WHO celebrates World Antimicrobial Awareness Week every year in November.
Finally, as the authors of The Lancet study highlighted, empowering scientific research for the development of vaccines and new antimicrobials is another way to safeguard the future. Breakthroughs. such as the first approved vaccine against malaria in October 2021, hold hope for alternative tactics against microbial infections.
Superbugs like tuberculosis and gonorrhoea are just the tip of the AMR iceberg. Common infections such as pneumonia and foodborne diseases are becoming increasingly challenging to treat. There is an urgent need to reflect the gravity of the situation by cutting unnecessary antimicrobials in livestock, keeping up the good hygiene measures Covid-19 has taught us, educating ourselves and those around us, and performing urgent research to find better treatments. Perhaps a little Collective thinking wouldn’t be a futile exercise either.
Simar Mann (she/her) is a final-year Infectious Diseases student.