The 12 most dangerous superbugs, ranked by the WHO

The World Health Organization says we need to step up the fight against a dozen bacteria that are growing resistant to all the antibiotics we have to treat them.

One of the scariest features of the antibiotic resistance crisis — which has been accelerated by how we overuse these drugs — is that pharmaceutical companies aren’t developing new antibiotics quickly enough. They also often place profits ahead public health when choosing which drugs to develop.

To push the industry to focus more on public health, WHO has released a list of the superbugs it thinks should be the highest priority.

“If we leave it to market forces alone,” said Marie-Paule Kieny, WHO’s assistant director-general for Health Systems and Innovation, in a press briefing, “the new antibiotics we most urgently need are not going to be developed in time.”

The list, drawn up by a group of international experts led by the WHO and the University of Tübingen in Germany, ranks bacteria based on their level of resistance to treatment, their mortality rates, their prevalence in the community, and the burden on the health system they cause. (Drug-resistant tuberculosis — while also a major threat — is not included here, said Kieny, because there’s already consensus that it’s a top R&D priority.)

“[The list] is not meant to scare people about new superbugs,” said Kieny. “It is intended to signal to the scientific community and the pharmaceutical industry that area they should focus on to address urgent public health threats.”

The 12 bugs on the list are classified as critical, high and medium priority. At the top of the critical category are Acinetobacter baumannii and Pseudomonas aeruginosa, which can cause deadly blood infections and pneumonia, most commonly in hospital patients. The third on the list, carbapenem-resistant enterobacteriaceae, is a family of germs that include Klebsiella and E. coli bacteria. They also commonly originate in hospitals, and can lead to urinary tract infections, bloodstream infections, and pneumonia with high mortality rates. (See the full list below.)

Among the high and medium priority categories were drug-resistant gonorrhea and salmonella bacteria.

Only a handful of new antibiotics have come on the market in the past decade, and health organizations such as the Infectious Diseases Society of America worry that progress on other drugs is “alarmingly elusive.”

Drugmakers have been reluctant to invest in antibiotics because they don’t offer great financial returns. Unlike treatments for chronic diseases, people only use antibiotics for short periods of time. And the calls to use them even more judiciously are not exactly an appealing business proposition for large pharmaceutical companies.

Though many of the best thinkers on antibiotics will argue that conserving the antibiotics we have is as important as — or even more important than — designing new drugs, there’s no denying that we need more antibiotics in the pipeline. To encourage research and development, experts have been calling for a global innovation fund to fill in the gaps left by industry and support research on antibiotic resistance and its solutions.

Several countries, including the United States and China, have already started developing such funds, and in February 2016 the US government launched the BARDA Biopharmaceutical Accelerator to fund antibiotic research through partnerships with industry and nonprofit organizations.

Antibiotic-resistant infections are associated with 23,000 deaths and 2 million illnesses in the US every year. Diseases like gonorrhea, carbapenem-resistant enterobacteriaceae, and some strains of tuberculosis no longer respond to any of the drugs we have.

Innovation in this area doesn’t just mean just developing new drugs. It also means investing in drug alternatives and better diagnostics to rapidly assess infections and avoid unnecessary prescribing. That’s why governments have been coming out with huge cash prizes for innovators who invent things like cheap, easy, and accurate point-of-care tests to diagnose bacterial infections.

The new WHO list is an attempt to get the pharmaceutical industry focused on the bugs that are wreaking the most damage, and encourage governments to figure out how to incentivize research. Otherwise, we are looking at “a post-antibiotic era,“ a threat on par with terrorism.