WHO has drawn up a list of the most threatening bacterial infections in a bid to guide and promote research and development (R&D) of new antibiotics, as part of efforts to address growing global resistance to antimicrobial drugs.
“This list is a new tool to ensure R&D responds to urgent public health needs,” said Marie-Paule Kieny, WHO’s Assistant Director-General. “Antibiotic resistance is growing, and we are fast running out of treatment options. If we leave it to market forces alone, the new antibiotics we most urgently need are not going to be developed in time.”
The WHO list is divided into three categories according to the urgency of need for new antibiotics: critical, high and medium priority.
The list highlights in particular the threat of gram-negative bacteria that are resistant to multiple antibiotics. These bacteria have built-in abilities to find new ways to resist treatment and can pass along genetic material that allows other bacteria to become drug-resistant as well.
The most critical group of all includes multidrug resistant bacteria that pose a particular threat in hospitals, nursing homes, and among patients whose care requires devices such as ventilators and blood catheters. They include Acinetobacter, Pseudomonas and various Enterobacteriaceae. These bacteria can cause severe and often deadly infections such as bloodstream infections and pneumonia.
The critical group of bacteria have become resistant to a large number of antibiotics, including carbapenems and third generation cephalosporins – the best available antibiotics for treating multi-drug resistant bacteria.
The second and third tiers in the list – the high and medium priority categories – contain other increasingly drug-resistant bacteria that cause more common diseases such as gonorrhoea and food poisoning caused by salmonella.
The list is also intended to inform the discussions of G20 health experts meeting this week in Berlin. Hermann Gröhe, Federal Minister of Health, Germany said, “We have to take joint action today for a healthier tomorrow. Therefore, we will discuss and bring the attention of the G20 to the fight against antimicrobial resistance. WHO’s first global priority pathogen list is an important new tool to secure and guide research and development related to new antibiotics.”
It is hoped that in prioritising the most urgent threats, governments will be spurred to put in place policies that incentivise basic science and advanced R&D by both publicly funded agencies and the private sector. In addition, the list will guide the WHO/Drugs for Neglected Diseases initiative, the Global Antibiotic R&D Partnership, which was set up last may be promote the not-for-profit development of new antibiotics.
The list was developed in collaboration with the Division of Infectious Diseases at Tübingen University, Germany, using a multi-criteria decision analysis technique vetted by a group of international experts.
The criteria for selecting pathogens on the list were: how deadly the infections they cause are; whether their treatment requires long hospital stays; how frequently they are resistant to existing antibiotics; how easily they spread between animals, from animals to humans, and from person to person; whether they can be prevented through good hygiene and vaccination; how many treatment options remain; and whether new antibiotics to treat them are already in the R&D pipeline.
“New antibiotics targeting this priority list of pathogens will help to reduce deaths due to resistant infections around the world,” said Evelina Tacconelli, Head of the Division of Infectious Diseases at Tübingen University, who contributed to the development of the list. “Waiting any longer will cause further public health problems and dramatically impact on patient care,” she said.
WHO priority pathogens list for R&D of new antibioticsPriority 1: CRITICAL
Acinetobacter baumannii, carbapenem-resistant
Pseudomonas aeruginosa, carbapenem-resistant
Enterobacteriaceae, carbapenem-resistant, ESBL-producing
Priority 2: HIGH
Enterococcus faecium, vancomycin-resistant
Staphylococcus aureus, methicillin-resistant, vancomycin-intermediate and resistant
Helicobacter pylori, clarithromycin-resistant
Campylobacter spp., fluoroquinolone-resistant
Neisseria gonorrhoeae, cephalosporin-resistant, fluoroquinolone-resistant
Priority 3: MEDIUM
Streptococcus pneumoniae, penicillin-non-susceptible
Haemophilus influenzae, ampicillin-resistant
Shigella spp., fluoroquinolone-resistant