How to combat the dangerous rise of antibiotic resistance
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 asStaphylococcus
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.
No comments:
Post a Comment