The list of priority pathogens consisting of 12 families of bacteria was drawn up as of the agency's efforts to address growing global resistance to antimicrobial medicines.
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.
A statement by the WHO shows that the most critical group of all includes multi-drug 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 can cause severe and often deadly infections such as bloodstream infections and pneumonia.
These bacteria have become resistant to the best available antibiotics for treating multi-drug resistant bacteria. The second and third tiers in the list contain other increasingly drug-resistant bacteria that cause more common diseases such as gonorrhea and food poisoning caused by salmonella.
"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," Dr Marie-Paule Kieny, WHO's Assistant Director-General for Health Systems and Innovation, said.
The list is intended to spur governments to put in place policies that incentivize basic science and advanced research and development by both publicly funded agencies and the private sector investing in new antibiotic discovery.
WHO spokesperson Christian Lindmeier;
The list was developed in collaboration with the Division of Infectious Diseases at the University of Tübingen, 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 when people in communities catch them; how easily they spread between animals, from animals to humans, and from person to person; whether they can be prevented, how many treatment options remain and whether new antibiotics to treat them are already in the pipeline.
Prof Evelina Tacconelli, the Head of the Division of Infectious Diseases at the University of Tübingen and a major contributor to the development of the list says that the new antibiotics targeting this priority list of pathogens will help to reduce deaths due to resistant infections around the world.
"Waiting any longer will cause further public health problems and dramatically impact on patient care," she adds.
However, tuberculosis - whose resistance to traditional treatment has been growing in recent years - was not included in the list because it is targeted by other, dedicated programmes. Other bacteria that were not included, such as streptococcus A and B and chlamydia, have low levels of resistance to existing treatments and do not currently pose a significant public health threat, the statement adds.