The World Health Organisation (WHO) estimates that up to half a million people per year develop multidrug-resistant tuberculosis, presenting an increasing threat to global health, while cases of particularly resistant bacteria strains have increased 600-fold in the U.K. between 2003 and 2015.

The rise of multidrug-resistant bacteria has been attributed to the overuse of antibiotics in medicine and farming, but a new study, published in May 2017 in the journal Infection, points to globalized drug manufacturing as the source, as it has gone through significant changes in recent decades, most notably with the outsourcing of active pharmaceutical ingredients (APIs) to Asia.

China and India are now the world’s largest API producers, but there has been a loss of transparency and oversight in a market that was worth US $160 billion in 2016. With an enormously complex supply chain, assessing production standards for APIs is one of the biggest challenges the industry faces.

While controls are being performed by the WHO as well as regulatory bodies, these checks usually focus on the purity and the safety of the substances produced, but not on environmental issues such as the significant amount of pollution that exists near drug production sites in China and India.

Christoph Lübbert and colleagues, along with a report by the Changing Markets Foundation, present the first systematic analyses of whether this pollution is associated with the presence of multidrug-resistant bacteria. Focused on Hyderabad, a hub for bulk drug manufacturing in India, the researchers collected and tested a total of 28 samples for the presence of drug-resistant bacteria. Sixteen of these samples were also tested for antimicrobial substances. All environmental samples tested showed high levels of antimicrobial substances.

Both the G20 and the WHO are aiming their efforts heavily on the issue of overuse of antibiotics. Lübbert’s report also suggests that the emergence of antimicrobial resistance is also a consequence of globalized drug manufacturing. They call on Western authorities and pharmaceutical companies to ensure that more stringent environmental regulations are put into place, as well as the updating of production plants and more costly waste management. Otherwise, the authors claim, the global threat of multidrug-resistant bacteria cannot be efficiently tackled.