Antibiotics
When
the drugs don’t work
How
to combat the dangerous rise of antibiotic resistance
May 21st 2016 | From
the print edition
SOME people describe
Darwinian evolution as “only a theory”. Try explaining that to
the friends and relatives of the 700,000 people killed each year by
drug-resistant infections. Resistance to antimicrobial medicines,
such as antibiotics and antimalarials, is caused by the survival of
the fittest. Unfortunately, fit microbes mean unfit human beings.
Drug-resistance is not only one of the clearest examples of evolution
in action, it is also the one with the biggest immediate human cost.
And it is getting worse. Stretching today’s trends out to 2050, the
700,000 deaths could reach 10m.
Cynics might be
forgiven for thinking that they have heard this argument before.
People have fretted about resistance since antibiotics began being
used in large quantities during the late 1940s. Their conclusion that
bacterial diseases might again become epidemic as a result has proved
false and will remain so. That is because the decline of common
19th-century infections such as tuberculosis and cholera was thanks
to better housing, drains and clean water, not penicillin.
The real danger is
more subtle—but grave nonetheless. The fact that improvements in
public health like those the Victorians pioneered should eventually
drive down tuberculosis rates in India hardly makes up for the loss
of 60,000 newborn children every year to drug-resistant infections.
Wherever there is endemic infection, there is resistance to its
treatment. This is true in the rich world, too. Drug-resistant
versions of organisms such as Staphylococcus aureus are increasing
the risk of post-operative infection. The day could come when
elective surgery is unwise and organ transplants, which stop
rejection with immunosuppression, are downright dangerous. Imagine
that everyone in the tropics was vulnerable once again to malaria and
that every pin prick could lead to a fatal infection. It is old
diseases, not new ones, that need to be feared.
Common failings
The spread of
resistance is an example of the tragedy of the commons; the costs of
what is being lost are not seen by the people who are responsible.
You keep cattle? Add antibiotics to their feed to enhance growth. The
cost in terms of increased resistance is borne by society as a whole.
You have a sore throat? Take antibiotics in case it is bacterial. If
it is viral, and hence untreatable by drugs, no harm done—except to
someone else who later catches a resistant infection.
The lack of an
incentive to do the right thing is hard to correct. In some
health-care systems, doctors are rewarded for writing prescriptions.
Patients suffer no immediate harm when they neglect to complete drug
courses after their symptoms have cleared up, leaving the most
drug-resistant bugs alive. Because many people mistakenly believe
that human beings, not bacteria, develop resistance, they do not
realise that they are doing anything wrong.
If you cannot easily
change behaviour, can you create new drugs instead? Perversely, the
market fails here, too. Doctors want to save the best drugs for the
hardest cases that are resistant to everything else. It makes no
sense to prescribe an expensive patented medicine for the sniffles
when something that costs cents will do the job.
Reserving new drugs
for emergencies is sensible public policy. But it keeps sales low,
and therefore discourages drug firms from research and development.
Artemisinin, a malaria treatment which has replaced earlier therapies
to which the parasite became resistant—and which now faces
resistance problems itself—was brought to the world not by a
Western pharmaceutical company, but by Chinese academics.
Sugar the pill
Because
antimicrobial resistance has no single solution, it must be fought on
many fronts (see article). Start with consumption. The use of
antibiotics to accelerate growth in farm animals can be banned by
agriculture ministries, as it has in the European Union. All the
better if governments jointly agree to enforce such rules widely. In
both people and animals, policy should be to vaccinate more so as to
stop infections before they start. That should appeal to
cash-strapped health systems, because prophylaxis is cheaper than
treatment. By the same logic, hospitals and other breeding grounds
for resistant bugs should prevent infections by practising better
hygiene. Governments should educate the public about how antibiotics
work and how they can help halt the spread of resistance. Such
policies cannot reverse the tragedy of the commons, but they can make
it a lot less tragic.
Policy can also
sharpen the incentives to innovate. In a declaration in January, 85
pharmaceutical and diagnostic companies pledged to act against drug
resistance. The small print reveals that the declaration is, in part,
a plea for money. But it also recognises the need for “new
commercial models” to encourage innovation by decoupling payments
from sales.
That thought is
taken up this week in the last of a series of reports commissioned by
the British government and the Wellcome Trust, a medical charity.
Among the many recommendations from its author, Jim O’Neill, an
economist, is the payment of what he calls “market-entry rewards”
to firms that shepherd new antibiotics to the point of usability.
This would guarantee prizes of $800m-1.3 billion for new drugs, on
top of revenues from sales.
Another of Lord
O’Neill’s suggestions is to expand a basic-research fund set up
by the British and Chinese governments in order to sponsor the
development of cheap diagnostic techniques. If doctors could tell
instantaneously whether an infection was viral or bacterial, they
would no longer be tempted to administer antibiotics just in case. If
they knew which antibiotics would eradicate an infection, they could
avoid prescribing a drug that suffers from partial resistance, and
thereby limit the further selection of resistant strains.
Combining policies
to accomplish many things at once demands political leadership, but
recent global campaigns against HIV/AIDS and malaria show that it is
possible. Enough time has been wasted issuing warnings about
antibiotic resistance. The moment has come to do something about it.
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