The rise of drug-resistant infections is outpacing the development of new treatments, leading to a global shortage of effective antibiotics, according to the World Health Organization.

The agency warns this “global health emergency” threatens to undo decades of progress made by advances in modern medicine without more funding for research and more responsible use of existing drugs.

A report by the WHO released on Wednesday found that only eight out of 51 new antibiotics identified in clinical pipelines will bolster today’s roster of treatments. That shortfall means doctors will be less effective at combating antibiotic-resistant infections as resistance rises -- an alarming trend given that drug-resistant tuberculosis alone kills around 250,000 people per year, according to the study’s authors.

“There is an urgent need for more investment in research and development,” WHO director-general Dr. Tedros Adhanom wrote in a release accompanying the report. “Otherwise we will be forced back to a time when people feared common infections and risked their lives from minor surgery.”

The report highlights 12 classes of priority pathogens, such as those that cause pneumonia or urinary tract infections, which are increasingly resistant to existing antibiotics and urgently in need of new treatments.

The authors also note that there are few oral antibiotics in development, which are essential for treating infections outside of a hospital setting.

Despite the obvious demand, many pharmaceutical firms are reluctant to bankroll research aimed at bringing new antibiotic drugs to market. WHO senior adviser Peter Beyer explains this is because investment dollars are generally better spent on treatments for chronic conditions versus short-term prescriptions.

“Diabetes, for example, (is) a chronic disease where people have to take treatment for their whole lifetime. With antibiotics you usually take a three-, six-, seven-day treatment course and then stop,” he told CTV News Channel. “It’s not a very attractive area of pharmaceutical research if you look at the return on investment.”

Beyer also notes generic drug competition is also to blame for the lack of corporate interest because it prevents companies from selling drugs at higher prices.

The task of funding such research is increasingly falling to governments. Germany, Luxembourg, the Netherlands, South Africa, Switzerland, the U.K. and a London-based biomedical research charity pledged a combined €56 million ($82 million) last month to support the Global Antibiotic Research and Development Partnership set up by the WHO and the Drugs for Neglected Diseases Initiative.

Beyer said the difficulty of developing new classes of antibiotics has been another hurdle for both privately and publically funded researchers.

“It is scientifically challenging. The big pharma companies have tried for a number of years. They have invested a lot of money and they have not found much,” he said.

Dr. Mario Raviglione, director of the WHO Global Tuberculosis Programme, estimates more than US$800 million is needed annually to fund research for new anti-tuberculosis medicines.

Beyer said more careful use of antibiotics, in both humans and animals will help delay the rise of antimicrobial resistance. The WHO is developing guidance for the responsible use of antibiotics in the humans and the agricultural sectors.

Dr. Suzanne Hill, director of the Department of Essential Medicines at the WHO, warns patients could be left with “no line of defence” without new treatments for certain types of “extremely serious infections that can kill patients in a matter of days.”