For years experts have warned that the rate at which pathogens are growing progressively resistant to antibiotics is bringing the world dangerously close to a “post-antibiotic” era.
Some say that threshold has already been breached. A lack of development of new antibiotics spurred by a growing number of drugmakers leaving the market coupled with the continued overuse of current treatments has left healthcare unprepared to address the growing threat of antimicrobial resistance.
A United Nations report on drug resistance released in April projected that without significant action being taken, such diseases will cause up to 10 million deaths worldwide annually by 2050, with more than 2 million occurring in high-income countries like the U.S.
The dearth of new antibiotics has led to more frequent use of drugs like colistin, long considered one of the very last lines of defense against pathogens that are resistant to all other treatment options.
But colistin’s future viability as a last-resort treatment has come under threat since scientists recently found a gene in salmonella bacteria that’s resistant to it.
“We are seeing a growing number of patients for whom we don’t have any treatment options, so we can’t treat their infection,” said Dr. Helen Boucher, director of the infectious diseases fellowship program at Tufts Medical Center in Boston and a member of the board of directors of the Infectious Diseases Society of America. “In many cases they die, and in other cases it means that they can’t have other medical care that they need.”
Some blame the for-profit pharmaceutical industry, which is the primary developer of antibiotics. Many companies have abandoned the antibiotics market because a new treatment is costly and can take up to a decade or longer to develop and carries no guarantees that it will generate a sizable return on investment.
Such was the case with San Francisco-based biotech firm Achaogen, which last year developed the antibiotic plazomicin for treating severe urinary tract infections; the company declared bankruptcy in April citing low sales of its drug.
“We’re seeing more companies getting out either voluntarily because they can’t make the argument for the cost-benefit of making antibiotics or the small companies that are trying to stay in the business even when they’re successful, the market isn’t really there,” said Kathy Talkington, project director of the Antibiotic Resistance Project at the Pew Charitable Trusts.
According to data compiled by Pew, plazomicin is one of only three new antibiotics approved in 2018. While more than 40 antibiotics are estimated to be in some stage of development, only 1 in 5 drugs that enter human testing get approved for patients, according to Pew.
The situation has raised questions about whether developing such a crucial component for public health should be left to market forces. “Leaving it to the market is not a good solution at this point,” Talkington said.
In spite of concerns, Boucher said some progress has been made toward antibiotic development in recent years. In 2016, HHS’ Biomedical Advanced Research and Development Authority launched the Combating Antibiotic Resistant Bacteria initiative, or CARB-X, which has to date awarded more than $118 million to 43 projects in seven countries to develop new antibiotic treatments.
But increasing the pipeline of new antibiotics is only part of the problem. Boucher and Talkington agree that a big contributor to antimicrobial resistance has been the overuse of the current supply of antibiotics by healthcare providers as well as livestock producers who have fed human antibiotics to animals to stave off infections and promote meat growth.
In a 2013 threats report, the Centers for Disease Control and Prevention estimated at least 2 million people are infected with antibiotic-resistant bacteria annually, and at least 23,000 people die as a result. But those numbers most likely underestimate the scope of the problem.
In an email, CDC spokeswoman Candice Hoffman stated that preliminary findings of an updated report due out later this year show that the burden of antibiotic resistance in the U.S. is larger than previously estimated. “The data show that prevention is protecting people, but that the threat of antimicrobial resistance remains high,” Hoffman wrote.
The federal government has yet to finalize requirements that would make antibiotic stewardship programs mandatory in all hospitals under the CMS.
As the number and strength of drug-resistant infections increase, Talkington fears for the worst if inaction continues. “We are already at a point where the tools that we have available are not working effectively,” she said. “The longer we wait to do something about it the more people are going to be negatively affected.”