A colorized scanning electron micrograph image of the O157:H7 strain of E. coli bacteria (Janice Carr/Centers for Disease Control and Prevention via AP)

The World Health Organization on Tuesday released new recommendations aimed at reducing the use of certain categories of “last resort” antibiotics as part of its ongoing efforts to combat the rise of superbugs.

Public health officials pointed to the increasing rate of new strains of pathogens that are becoming antibiotic-resistant, saying these “nightmare bacteria” pose a catastrophic threat. Overuse of antibiotics in livestock as well as in humans is the main cause.

Such resistance has created a world in which even the most minor of infections and illnesses can quickly turn deadly and in which diseases once thought conquered, such as tuberculosis and gonorrhea, are becoming untreatable in more and more cases.

The WHO's new advice, the biggest revision in 40 years regarding this last-resort category of drugs, puts antibiotics in three categories — watch, access and reserve — that describe which antibiotics can be used more liberally and which ones should be saved for more serious cases.

“The aim is to contain antibiotic resistance, optimize antibiotic treatment and to preserve 'last-resort' antibiotics,” Marie-Paule Kieny, assistant director-general for health systems and innovation at the WHO, told reporters during a briefing from Geneva. “We don't see this as a quick-fix solution,” she added, but scientific evidence supports the idea that this could reduce the number of dangerous infections.

The last time scientists discovered a truly new antibiotic was in 1984. Here's why. (Pew Charitable Trust)

Overall, the recommendations involve encouraging the use of penicillins in more cases while reducing the use of newer and more expensive antibiotics.

Medicines such as amoxicillin, which is commonly used to treat a wide range of ailments from ear infections to pneumonia, will be in the “access” group. Those, according to the WHO documentation, should be “available at all times.”

The “watch” group includes first- or second-line treatments such as ciprofloxacin, which many people might know from taking it for strep throat or sinusitis. The use of these medications should be “dramatically reduced,” the global health group recommended.

The final “reserve” group will include antibiotics that are our current last line of defense. These include colistin and some cephalosporins, which the WHO says emphatically should now only be used “in the most severe circumstances when all other alternatives have failed.” In case that wasn't clear enough, the WHO gave as an example “life-threatening infections due to multidrug-resistant bacteria.”

The updates are part of the WHO's Model Lists of Essential Medicines for 2017, which is updated every two years as a guide for what each country should stock. The list is used by many national governments as the basis of their own recommendations, regulations and insurance coverage decisions.

How companies that sell the new classes of antibiotics — and will certainly stand to lose money — react to the recommendations remains to be seen. Suzanne Hill, director of essential medicines at the WHO, acknowledged that the economic incentive system in drug development revolves around sales and that there may be “a very large economic impact” for those companies with antibiotics in the most restricted category.

“We need to work out how we pay the companies to not market it and to keep it in reserve. This is going to be a challenge,” Hill said.

The WHO said it focused its work on 39 essential antibiotics and how they applied to 21 of the most common general infections; the recommendations will be expanded if they are proven useful. Numerous medical groups around the world, such as the American Academy of Pediatrics in the United States, have weighed in more recently on the use of antibiotics for various conditions and when not to use them. But the WHO's advice provide a more comprehensive framework for addressing the issue.

Earlier this year, the European Center for Disease Prevention and Control estimated that 25,000 Europeans are dying from antibiotic-resistant bacteria each year. The U.S. Centers for Disease Control and Prevention has said that at least 23,000 Americans die from such infections annually.

The United Nations General Assembly in 2016 secured a commitment from heads of state to join to combat the problem — only the fourth time it had taken on a health issue. The previous actions involved HIV, noncommunicable diseases and Ebola.

Margaret Chan, who was then director-general of the WHO, characterized antibiotic resistance as a fundamental threat to human security and warned that the world is “running out of time.”

One report, commissioned by the United Kingdom, estimated that if the proliferation of superbugs is not stopped, 10 million people worldwide could be dying each year by 2050. That's more than the number killed by cancer.

Marcus Sprenger, WHO director of antimicrobial resistance, said that as the world works to fight superbugs, leaders should not lose sight of the fact that many people, especially those in impoverished and underdeveloped countries, still don't have access to modern antibiotics.

“When it comes to antimicrobial resistance,” Sprenger said, “there are always two sides.”

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