Antimicrobial resistance (AMR) is emerging fast in livestock in the developing world, with northeast India and northern China among the most worrisome “hotspots”, says a first-ever study mapping AMR in low and middle-income countries, published this week in Science. Parts of Turkey, Kenya, Brazil, Egypt, Vietnam and South Africa were also noted as areas of high concern.

Kenya, Morocco, Uruguay, southern Brazil, central India, and southern China also were noted as areas where resistance is starting to emerge.  There was uncertainty about trends in the Andes, the Amazon region, West and Central Africa, the Tibetan plateau, Myanmar, and Indonesia, the authors noted. And data was contradictory for Ethiopia, Thailand, Chhattisgarh (India), and Rio Grande do Sul (Brazil).

The study found that in the low and lower-middle income countries reviewed (LMICs), levels of resistance for the most common classes of antibiotics important to human health were approaching or even exceeding levels of AMR found in Europe and the United States, which have been using antibiotics in livestock production since the 1950s.

The authors recommended that governments of the lower-middle income countries where resistance is rising, together with high-income countries that help drive the global market for meat, work together to reduce the threat of rising AMR.

The study pointed out that industrial livestock production, which has also been linked to driving climate change, consumes some 73% of all antimicrobials produced annually. Governments of countries at risk could take “immediate action” in regulating antibiotic use, and adopting biosafety practices more common in high income countries, the authors said.

The studied identified and reviewed 901 point prevalence surveys of AMR resistance in low- and middle- income country livestock settings for the common indicator pathogens: Escherichia coli, Campylobacter spp., nontyphoidal Salmonella spp., and Staphylococcus aureus.

It found that from 2000 to 2018, the proportion of pathogens displaying resistance to common anti-microbial agents greater than 50% increased from 0.15 to 0.41 in chickens and from 0.13 to 0.34 in pigs, while plateauing between 0.12 and 0.23 in cattle.

Alarmingly, resistance rates ranged from as high as 40-80% to first-line antibiotics such as penicillin in parts of Asia to ~18-40% in “drugs of last resort,” or the most potent antibiotics such as colistin, in the Americas and Asia.

The authors stressed that high-income countries in Europe and North America that are driving meat demand need to to support the “transition to sustainable animal production” in LMICs. They note that many developed countries that have strict regulations on domestic agricultural antibiotic use still import meat produced in countries with more lax laws.

“We [high-income countries] are largely responsible for this global problem we’ve created,” said Thomas Van Boeckel, a co-author of the study and epidemiologist at the Swiss Federal Institute of Technology in Zurich, to Nature News. “If we want to help ourselves, we should help others.”

The US, the 28 countries of the European Union, China, Brazil, and India all rank among either the top ten meat importers and/or exporters according to the Food and Agricultural Organization (FAO) of the United Nations.

For quite some time, scientists have expressed uncertainty about whether AMR levels could be lower in low and middle income countries due to more limited access to veterinary antimicrobials and less meat consumption overall. But the study’s findings seem to indicate that AMR in LMIC settings is also exacerbated by lower surveillance and less restrictive veterinary regulations that may be common to such settings.

Using geo-spatial mapping and analytic techniques, the authors collated data from a range of smaller studies to analyze risks of antimicrobial resistance on a global scale. They note that data is still limited, particularly for the Americas, which hosts some major meat exporters, so it is difficult to draw definitive conclusions about that region as well as about large parts of Africa.

Image Credits: S. Jetha/Science, Science/resistancebank.org.