At the start of World Antibiotic Awareness Week (WAAW) 2019, Lecturer in Molecular Microbiology Dr Tina Joshi examines the interaction between what are arguably the two greatest threats to humankind: climate change and the rise of antimicrobial resistance (AMR).
Bacteria previously susceptible to treatment have evolved to develop resistance to commonly used antibiotics, rendering them ineffective against infection. The result is a threat to the very foundations of modern medicine and a phenomenon that is already killing at least 700,000 people each year globally. Indeed, it has recently been reported that the leading cause of death and disease in leukaemia patients in India is infection with bacteria resistant to the last line of antibiotics.
In April, the UN released a report stating that by 2050, if no action is taken, drug-resistant diseases could cause 10 million deaths each year by 2050, and damage to the economy as catastrophic as the 2008–2009 global financial crisis. In the UK, a separate report by the government predicted drug-resistant infections are set to kill more people than cancer and diabetes combined by 2050 – making antibiotic resistance one of the biggest threats to global human health.
Held every November since 2015 and led by the World Health Organisation (WHO), WAAW aims to increase global awareness of antibiotic resistance and to encourage best practice among the general public, health workers and policy makers to limit the development and distribution of drug resistance.
The WHO blames the persistent overuse and misuse of antibiotics in human and animal health for encouraging the emergence and spread of antibiotic resistance. This is, of course, true, but it’s also interesting to look at some of the environmental and social factors that facilitate AMR.
Recent studies have suggested a link between increasing temperatures due to climate change, and the spread of AMR. Research conducted in Europe, with results published this year, reported antibiotic-resistant bacteria were more likely to be found at warmer times of the year. The findings reinforced a 2018 study carried out in the USA.
Another key factor is poverty and its consequences. Globally, the links between climate change, mass migration, stifled economic growth and natural disasters are plain to see, something acknowledged by the World Bank when it said that without urgent action, climate impacts could push an additional 100 million people into poverty by 2030.
This year, a comprehensive analysis of sewage collected across 60 countries was published which showed that sanitation and health are closely linked to levels of AMR. Researchers found that the world's countries fall into two groups in AMR terms: North America, Western Europe, Australia and New Zealand generally have the lowest levels while Asia, Africa and South America have the highest.
They concluded that while the relative use of antibiotics and other antimicrobials – broadly higher in developing countries – as part of the picture, the most important factors were the quality of sanitation systems and the general health of the population. Poor sanitation offers bacteria a breeding ground from which drug-resistant microbes can spread, and poor hygiene and infection control makes it much easier for them to do so.
A lack of effective sanitation can also help explain the spread of AMR genes into the marine environment. When faecal matter containing such genes is discharged into the sea untreated, it can be transported to the four corners of the globe through mechanisms such as ocean currents and migrating wildlife. Earlier this year the discovery of AMR genes was reported in Svalbard, high in the Arctic Circle, and such genetic material has also been found deep in the oceans.
Like climate change, in today’s globalised world the threat of AMR requires an international response. Drug resistant infections do not respect national borders and good work in developed countries has to be matched, encouraged and supported in poorer regions.
The consequences of an insufficient or uncoordinated response, while they may hit first and hardest in developing countries, will soon enough make themselves felt in all our lives.However, there is also a critical need for new antibiotics, and scientists around the world, including here at the University, are working to develop what would be the first new class of the drugs in three decades. Colleagues in many different areas are engaged in research around antibiotic resistance, from examining deep-sea sponges in the search for new antibiotics, to inventing new technologies to detect antibiotic resistance in blood samples for more effective prescribing of antibiotics.