The rise of drug-resistant bacteria has focused attention on the urgent need for new antibiotics, but that is not the only pressing challenge if superbugs are to be kept in check.
Just as important is finding better ways of diagnosing infections to reduce the wasteful use of antibiotics that is fuelling antimicrobial resistance.
Most prescriptions for antibiotics are issued by doctors based on an educated guess about the cause of a patient’s illness. In many cases, the guess turns out to be wrong. The bug might be viral rather than bacterial, or it might not be an infection at all. This means that antibiotics are often taken unnecessarily.
“Part of the problem is that it is cheaper and quicker to prescribe an antibiotic just in case it is effective,” says Des Walsh, head of infections and immunity at the UK Medical Research Council.
An academic study showed that more than two-thirds of antibiotics given for respiratory problems in the US were probably prescribed inappropriately.
Wasteful use of this kind accelerates the development of drug resistance by increasing the opportunities for bacteria to find ways of evading antibiotics. These mutant bugs then proliferate through natural selection, leaving medicines powerless to stop them.
Better diagnostic capabilities would help combat this problem by ensuring that antibiotics were given only to patients who truly needed them. Dr Walsh warns that the implications will be far-reaching if the challenge is not met.
“We need to be able to tell accurately whether an illness is due to a bacterial infection and if so which antibiotic to use, or we risk losing a raft of drugs that are crucial to prevent infections after serious operations like Caesareans, transplants, or to treat illnesses like pneumonia or kidney infections,” he says.
While other areas of medical diagnostics have advanced rapidly, the tests carried out for infections are little changed from the days of Alexander Fleming, who discovered penicillin. Bacteria must be sent to a laboratory and cultured for 36 hours or more to confirm the type of infection and the drugs to which it is susceptible.
Plenty of companies are trying to bring the process up to date. California-based GeneWeave is among those developing rapid-fire tests to match the right antibiotic to the right bug without the need for traditional lab work. The company was acquired by Roche, the Swiss drugs and diagnostics group, in August in a deal worth up to $425m.
However, while technology is advancing there are economic barriers to adoption. The low price of antibiotics means there is little incentive for doctors to invest in diagnostic techniques that carry a high upfront cost. A device made by BioFire Diagnostics, a US unit of France’s BioMérieux can test for several pathogens (micro-organisms, such as bacteria and viruses) in an hour, but costs about $35,000. This might represent good value to a health system and society as a whole but few immediate benefits accrue to the general practitioner whose prescribing habits need to change.
How can this market failure be overcome? The UK has offered a financial incentive to anyone who can come up with a solution. The £10m Longitude Prize, set up by Nesta, a British lottery-funded innovation charity, is open to any group or individual that devises a cost-effective and easy-to-use test for bacterial infections that can be used anywhere in the world to diagnose bacterial infections accurately in 30 minutes.
The prize was first offered by the British government in 1714 to find a way to measure longitude at sea for navigation. The country was vying with European rivals for maritime superiority. It was revived in 2014 when antimicrobial resistance was chosen by a UK public vote as the new challenge to be tackled.
More than 100 entrants from 26 countries have so far registered for the competition, which runs until the end of 2019. A winner could be declared at any time if all the criteria are met but the first eight entries reviewed this year were deemed to have fallen short.
“Although they were bold, innovative and, for the most part, useful, none met the extremely difficult criteria we set to win the prize,” said Peter Piot, director of the London School of Hygiene & Tropical Medicine and co-chairman of the prize’s advisory panel.
An estimated 700,000 people a year are dying from drug-resistant infections — and that figure could rise to 10m by 2050
Another British initiative to solve the problem is being led by Jim O’Neill, the UK Treasury minister and former Goldman Sachs chief economist, who was appointed by Prime Minister David Cameron to chair an inquiry into antimicrobial resistance.
His panel has called for governments and the pharmaceutical industry to set up a $2bn innovation fund to support development of diagnostic tests as well as new antibiotics, and a further pot of at least $16bn to guarantee a revenue stream for successful products.
An estimated 700,000 people a year are already dying from drug-resistant infections worldwide. This could reach 10m by 2050, costing the global economy $100tn in lost output, if no action is taken, according to Lord O’Neill.
While such warnings have become more strident, they are not new. The danger of antimicrobial resistance has been known since Fleming himself raised the issue. He sounded the alarm in his speech accepting the 1945 Nobel Prize in medicine. Seventy years later, the world is finally taking notice.