As antibiotics fail, global consumption is soaring, further driving drug resistance

Worldwide use of antibiotics in humans soared 39 per cent between 2000 and 2015, according to the most comprehensive assessment of global trends to date.

The study, by researchers at ETH Zurich, the University of Antwerp and Princeton University analysed human antibiotic consumption in 76 countries.

Surveillance data on country-level antibiotic use are needed to:

• monitor national and global trends over time;
• compare antibiotic use among countries;
• provide a baseline for the evaluation of future efforts to reduce antibiotic use;
• enable epidemiological analysis of the association between antibiotic use and resistance over time;
• support policies that aim to reduce antibiotic resistance.

Given the urgency of the threat posed by rising antimicrobial resistance levels and in the absence of global, publicly funded, harmonised surveillance data on antibiotic use, the researchers used pharmaceutical sales data to document global trends in antibiotic consumption.

The research, published last month in in the Proceedings of the National Academy of Sciences, found that while antibiotic consumption rates increased worldwide, there were particularly dramatic increases in low-income and middle-income countries.

Antimicrobial resistance is driven in large part by inappropriate consumption, for example, when patients are prescribed antibiotics for viral infections.

When antibiotic resistance emerges in one location it quickly spreads to others, and the study underscores the need for consistent global surveillance of antibiotic resistance and of policies to curtail unnecessary antibiotic use.

However, while reducing antibiotic use is critical, increasing access to antibiotics in lower-income countries is also necessary, as these countries suffer from the highest rates of illness and death caused by infectious disease, the study researchers pointed out.

“Finding workable solutions is essential, and we now have key data needed to inform [these],” said study co-author Eili Klein. “Now, more than ever, we need effective interventions, including stewardship, public education, and curbing overuse of last-resort antibiotics.”

Major findings from the study are:

• Total global use of antibiotics in humans was estimated to have increased by 65 per cent between 2000 – 2015.
• Antibiotic use in low and middle income countries increased 114 per cent in total and some had rates of consumption that surpassed those of high-income countries. However, many low and middle income countries still have considerably lower per capita consumption rates than high-income countries, due to access issues such as the high cost of drugs and patent protections.
• The consumption rate of broad-spectrum penicillins, the most commonly consumed class of antibiotics, increased 36 per cent between 2000 and 2015, globally. The greatest increase was in low and middle income countries, where the rate of antibiotic consumption increased 56 per cent, compared to 15 per cent in high-income countries.
• Consumption of new and last-resort antibiotic classes, such as linezolid, carbapenems, and colistin, increased significantly in nearly all countries.
• Consumption increases in low and middle income countries were driven largely by economic growth, a pattern not seen in high-income countries.

Despite the rising rates of antibiotic use worldwide, the results suggest that reducing antibiotic consumption is possible. Overall, consumption in high-income countries taking measures to reduce inappropriate use actually fell slightly over the study period.

In addition, the considerable variation in per capita use across high-income countries suggests that there are public health lessons to be learned, the researchers say.

Study co-author Ramanan Laxminarayan, director of the Centre for Disease Dynamics, Economics & Policy at Princeton, noted more than a year has passed since the United Nations General Assembly recognised the global threat of antibiotic resistance, yet little action has been taken since then.

“We must act decisively and we must act now, in a comprehensive manner, to preserve antibiotic effectiveness,” Laxminarayan said. “That includes solutions that reduce consumption, such as vaccines or infrastructure improvements, particularly in low-income and middle-income countries. New drugs can do little to solve the resistance problem if these drugs are then used inappropriately, once they are introduced.”