A dramatic increase in the use of antibiotics worldwide has prompted public health experts to call for limits to the consumption of the drugs and focus renewed efforts on increasing sanitation and vaccines to combat infections.

A study conducted by an international team of researchers found worldwide consumption of antibiotics jumped 65 percent from 2000 and 2015, based on sales figures from 76 countries. The rise was driven almost entirely by increased use in poorer countries, the study from the Washington-based Center for Disease Dynamics, Economics and Policy showed.

"We saw a dramatic increase in antibiotic use globally and this is mostly from gains in low- and middle-income countries where economic growth means they have greater access to the drugs," author of the study Eili Klein said.

"While it's generally positive that there's better access to effective antibiotics in these countries, there's the potential for serious problems down the road from overuse. We know there's a lot of inappropriate use in high-income countries, and many of these lower income countries do not have the same controls in place."

The danger of overuse of antibiotics has become clear as a wave of drug-resistant infections have left health care providers unequipped to address new sicknesses.

Drug-resistant strains now kill more than 500,000 people annually worldwide, with a tenth of all deaths in the U.S. and Europe. If left unchecked, these diseases are likely to increase in variety and scale.

"Our modern medical system is built on effective antibiotics," Klein said. "If our antibiotics stop working, if bacteria become resistant to most of them, medicine will be in trouble. The worry is that people don't do anything about it."

Klein and his co-authors urge "radical rethinking" of policies to cut back antibiotic usage, advocating greater investment in sanitation, hygiene and vaccinations in countries where antibiotic use is steadily climbing.

The study found that despite the rise in usage, low- and middle-income countries still use antibiotics far less than richer nations, who consume the drugs and nearly twice their rate.

In Turkey, where antibiotic consumption is significantly higher than other countries, antimicrobial resistance has become a serious concern. A 2014 study by the World Health Organization (WHO) ranked Turkey among the top three countries in terms of weak antimicrobial resistance to several infections.