HIGH blood pressure, diabetes, epilepsy and asthma鈥攖he list of the most
common ailments in this particular clinic is unremarkable. What鈥檚 surprising is
that the setting is rural Tanzania.
The clinic is one of four set up by George Alberti of Britain鈥檚 Royal College
of Physicians and his colleague Nigel Unwin of the University of Newcastle upon
Tyne to monitor and treat chronic diseases in Africa. Such illnesses account for
up to a third of all deaths in Tanzania and, as urbanisation increases, the
burden is expected to grow. 鈥淲e are a small group beating away at an enormous
problem,鈥� says Alberti.
The work is indicative of a recent shift in priorities, led in part by the
World Health Organization, towards non-communicable diseases. Increasingly,
people in the developing world are leading Western lifestyles. That means
healthier childhoods and longer lives, but as more people survive to adulthood
the incidence of cancer and heart disease is rising, spurred on by the
increasing adoption of unhealthy Western diets. Most public health experts say
such trends indicate more resources are needed to fight the diseases of old
age.
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But some fear that the pendulum may have swung too far. No less a figure than
David Heymann, the executive director of WHO鈥檚 communicable diseases division,
is warning that predictions about patterns of chronic disease are
premature鈥攁nd that we ignore emerging diseases and growing drug resistance
at our peril. His concerns, which highlight tensions within WHO, are backed by a
World Bank report that says targeting non-communicable diseases (NCDs) will
simply widen the gap between the rich and the poor. So who鈥檚 right?
The issue was first brought to the attention of policy makers in 1996, when
the World Bank published a seminal report by Christopher Murray of the Harvard
School of Public Health and WHO researcher Alan Lopez. As well as making a
thorough survey of all the health problems affecting the world鈥檚 population and
counting up deaths, they devised a new way of looking at health, the
鈥渄isability-adjusted life year鈥� or DALY. In essence, DALYs measure the years of
healthy life lost because of premature death or disability.
Because DALYs show which diseases are the greatest burden, rather than simply
the greatest killers, this approach led to a much greater emphasis on chronic
diseases such as cancer and mental illness, previously neglected as global
health problems. The report also predicted that by 2020, NCDs would be the big
killers, causing 73 per cent of all deaths worldwide, compared with 15 per cent
from infectious diseases (see Diagram).
According to Murray and Lopez鈥檚 report,
the biggest emerging threats to world health were heart disease and
depression.
Economist Dean Jamison of the University of California at Los Angeles helped
draft a companion report, co-authored by Tore Godal and James Tulloch of the
WHO. Their job was to look at the 鈥渂est buys鈥� for those who fund research, and
they too made NCDs a priority. The findings prompted Gro Harlem Brundtland, who
took over as director-general of the WHO in 1998, to create a non-communicable
diseases division, and a new agency, the Global Forum for Health Research, to
identify neglected areas.
So are the principal threats to developing countries really obesity, heart
disease and lung cancer, or should we still be concentrating our research and
treatment efforts on the huge developing world blights of malaria and TB?
Heymann is worried that a shift of attention and resources towards NCDs could
have severe consequences. 鈥淚f priorities shift, then the same level of funding
won鈥檛 necessarily remain for infectious diseases, and if funding drops for
infectious diseases, it has been shown time and time again that they will come
back. With increasing drug resistance, we are losing the tools we have.鈥�
He also fears the unknown, such as influenza pandemics and new diseases.
鈥淭here are certain things that can鈥檛 be modelled into the future. Who would have
known in the early 1980s that HIV would be the world problem that it is today?鈥�
Heymann also argues that we have a 鈥渨indow of opportunity鈥� to eradicate some
infectious diseases, and that if we don鈥檛 seize this opportunity, new infections
or drug resistance might make it impossible to eliminate these diseases.
Now he has support in the form of a major World Bank report, The Burden
of Disease among the Global Poor, which concludes that targeting NCDs would
mostly benefit people in richer countries, thus increasing the gap in life
expectancy between the rich and the poor. Concentrating on infectious diseases,
on the other hand, would help the poor and decrease the gap in life expectancy.
This is because infectious disease has a hugely disproportionate effect on
people in the developing world.
The paper鈥檚 author, Davidson Gwatkin of the International Health Policy
Program in Washington DC, says that the fairest policy is to concentrate on
infectious diseases. 鈥淚n the 1970s and 1980s, people were thinking primarily in
terms of the world鈥檚 poor,鈥� he says. 鈥淏ut by the 1990s, the focus had shifted
away from the poor, towards the whole world. This gave a higher priority to
狈颁顿蝉.鈥�
The report has ruffled feathers. 鈥淲e are not happy with the methods used,鈥�
says Murray, now at the WHO, while Alberti calls the recommendation 鈥渁 very
short-sighted policy鈥�. 鈥淚t is in very gross error,鈥� says Thomas Nchinda, a
public health specialist at the WHO鈥檚 Global Forum for Health Research. 鈥淭he
impression that developing countries should forget about NCDs is terrible.鈥�
He points to the prevalence of high blood pressure in some developing
countries. 鈥淲e must not wait 30 years until these people die of heart attacks,鈥�
he says. 鈥淲e must start preventative action now.鈥� He rejects the notion that
targeting NCDs will benefit primarily the rich. 鈥淭he targets for action are very
specifically the developing countries.鈥�
However, David Warrell, professor of tropical medicine and infectious
diseases at Oxford University, agrees that the threat of NCDs may have been
overestimated. 鈥淚n reality, we are not seeing that shift in adult morbidity and
mortality figures. It is a real phenomenon, but it is not taking over,鈥� he says.
鈥淲e tend to think that infectious diseases have been conquered. But we don鈥檛
have a vaccine for TB, or for HIV, or for dengue.鈥�
Warrell foresees a bleak future unless more is done to combat infectious
diseases. Global warming is allowing insect-borne diseases such as dengue and
malaria to spread. Crowded refugee camps鈥攎ost recently in Mozambique and
Madagascar鈥攑rovide a breeding ground for infectious diseases. We are
seeing the emergence of new infectious diseases, and the re-emergence of old
ones, such as diphtheria in Eastern Europe, and also TB. Then there is drug
resistance. The effect of the problem is much greater in developing countries,
because newer drugs are generally much more expensive鈥攁 single case of
multidrug-resistant TB can cost a staggering $50 000 to cure, for
example, far beyond the means of most countries.
Nonetheless, Derek Yach, the head of the new NCD group at the WHO, disputes
the notion that targeting NCDs will widen the gap between rich and poor. He even
has a conspiracy theory about the re-emerging concern over health spending
priorities. 鈥淭he tobacco industry tried to influence policy makers within the
WHO, to cut off funds from tobacco control,鈥� he says. 鈥淭hey used the same
argument, that targeting NCDs would benefit developed countries more than the
developing world. There has been an attempt to divide the public health
community into those who advocate infectious disease control, and those who
advocate NCD control.鈥�
But Yach holds out an olive branch to his opponents. 鈥淚n some areas, there鈥檚
a natural synergy,鈥� he says. He cites the combination of TB and tobacco as an
example. Over three-quarters of TB sufferers also smoke and need鈥攂ut are
not yet given鈥攎odern aids to help them quit.
Nonetheless, the tensions remain. Each year the world spends between
$50 billion and $60 billion on medical research. Over 90 per cent
of this is aimed at helping just 10 per cent of the world鈥檚 population. With
funds so limited, and millions dying of diseases that can be treated or
prevented, health authorities can鈥檛 afford to get their priorities wrong.