Health relies on good food, human rights, education and prosperity – and contributes to them too, explains Alfred Sommer –

The United Nations, in its Millennium Development Goals, provided explicit, quantitative targets for reducing a wide variety of human miseries, including poverty, hunger, excessive mortality and insecurity. These, least of all health issues, are not problems that can be solved in isolation from each other.

The population grows when the number of children who are born and survive exceeds the number of people who die. For most of human history, surviving births did not much exceed deaths, leaving the planet sparsely populated until relatively recent times.

The first stimulus to growth, settled agricultural communities, was made possible by cultivation of grain and expanded trade, which depended upon general security. This generated the excess capital (and food) required to build the first great civilizations. Members of these better-fed and better-housed societies lived longer, although the growth of cities and concomitant crowding increased the risk of infectious disease. Distances between people shrank, facilitating direct transmission of microbial agents, and increasing the difficulty of disposing of growing amounts of human and animal waste, which contaminated food and water.

Epidemics became more frequent and were sometimes calamitous. In the 14th century, the Black Death (plague spread by flea-infested rodents), wiped out one-third of Europe’s population, depopulating the countryside. Whole societies collapsed. It took centuries for Europe to recover its health and productivity. For hundreds of years, China’s population went through recurrent cycles of expansion and sudden implosion.

Living longer

But several centuries ago population growth resumed and, except under unusual circumstances, it has been growing ever since. This reflects longer life expectancy in the face of high fertility. Life expectancy (at birth) is largely determined by the likelihood of children surviving infancy and the first five years of life. The rate at which young children die has a far greater impact on life expectancy than does the age at which the elderly succumb, simply because there are many more lost years at stake. Apart from the very old, young children are most vulnerable to death and disease, particularly from malnutrition and infections. Child survival (or life expectancy at birth) is therefore an important indicator of societal wellbeing.

A child’s health is, to a very large degree, determined by the health of its mother and by her knowledge of good child-rearing practices and freedom to follow them. Mothers cannot perform this vital function if they are uneducated, bound by inappropriate customs or if they themselves die prematurely.

High fertility (many pregnancies during a woman’s reproductive period) is driven, to a large degree, by high childhood mortality. In many low-income countries, children – particularly male children – are the sole support of elderly parents. In medieval Europe (or 20th century Asia and Africa) half of all children died before their fifth birthday. The average woman had to bear eight children to ensure that she had two sons who survived childhood. When child survival rates improve, fertility rates decline and populations begin to stabilize.

The under-fives mortality rate has markedly declined around the world. In high-income countries it is now below 10 per 1,000 live births. In sub-Saharan Africa it is roughly 170, and in South Asia 98. But it is important to recall than many countries that today enjoy high incomes and high child survival rates, like Japan, had high child mortality rates (similar to many of today’s developing countries) well into the 20th century.

Thank public health

In 1900, average life expectancy in America was barely 40 years and in Japan, it was even shorter. Today it is 77 and 81, respectively, in the two countries, largely because infants and young children are much more likely to survive. This dramatic improvement was largely unrelated to direct investments in health or the discovery of high-tech magic bullets. Measles (chart 2), typhoid and tuberculosis deaths in America declined before there was a vaccine to prevent measles or effective anti-microbial therapy for typhoid or tuberculosis. Everyone benefited from: better nutrition, which dramatically increases resistance to serious infections; better living and safer working conditions, with improved ventilation; clean water and effective sanitation, which virtually eliminate the risk of waterborne diseases such as typhoid; and isolation and quarantine of infected patients (tuberculosis) and their contacts (measles). Successful control of the recent severe acute respiratory syndrome (SARS) outbreak depended entirely on this same basic containment strategy.

Immunization, a direct population-wide health intervention, has provided additional protection from measles, tetanus, diphtheria, pertussis (whooping cough), polio and other infections. But vaccines require a stable, functioning health delivery system. For maximum benefit, immunization needs to be added on top of basic societal standards of adequate nutrition, housing, hygiene and sanitation.

Security and political will are essential to health. A concerted global effort eradicated smallpox, once a dreaded, naturally occurring infection with high mortality and, to this day, no effective treatment. Polio, on the other hand, for all the wrong reasons is still with us. Eradicated from the Americas 10 years ago, the number of cases worldwide had declined from 350,000 in 1988 to fewer than 2,000 in 2002 – by an astounding 99%.

But last year the fundamentalist Muslim governor of Nigeria’s Kano state halted all polio immunization efforts because of alleged (and unsubstantiated) claims that it was part of a plot to sterilize Muslim girls. By the time he relented, polio had spread to 12 African countries that had been freed of the disease, dramatically setting back global eradication efforts and forcing the rest of the world to continue vaccination programmes. Money helps, too

Life expectancy, child survival and maternal mortality are all closely correlated, and income and female education also come into the picture. Life expectancy increases dramatically as national income per capita approaches $2,000, and more gradually thereafter, reflecting investments in basic living standards essential to health (chart 3). Income distribution matters too. Some low- and middle-income countries (Vietnam and Cuba, for example) have disproportionately long life expectancies, while in some wealthy countries (the Gulf states) life expectancy is disproportionately short.

In general, health and longevity were improving nearly everywhere by the mid-1980s. Some 80% of African children were receiving routine childhood immunizations, and both child and maternal health were benefiting from birth spacing, fewer unintended pregnancies (therefore, fewer maternal deaths), more widespread breast-feeding, and better maternal nutrition and education.

A worsening outlook

In contrast, the past decade has been a global health disaster. While the health indices of high-income countries continue to improve, these have dramatically worsened in much of the rest of the world. Fewer than half of Africa’s children presently receive basic childhood immunizations. Russian men lost five years of life expectancy following the break-up of the Soviet Union, partly from a collapse of basic health services (and an attendant increase of preventable infectious diseases), and partly from deteriorating living conditions and a growing use of tobacco and alcohol, much of it the result of insecurity and uncertainty.

HIV/AIDS has already had a disastrous impact on many populations, particularly in sub-Saharan Africa, where it has disproportionately affected the already scarce educated and professional classes. This has fed political instability, curtailment of human rights and a further breakdown in societal security. The power struggles and chaos of Africa’s Great Lakes region illustrate the enormous health consequences inflicted on displaced persons, who cannot farm (to feed themselves), educate their children or build viable infrastructures essential to health.

Women’s lot

Women (and secondarily their children) have suffered from rape, trafficking and the loss of educational opportunities, family planning services, prenatal care and trained midwives. Maternal deaths in industrialized countries are now 13 per 100,000 live births. Rates in sub-Saharan Africa and some south Asian populations are 50 to 100-fold higher (940 for all of sub-Saharan Africa; 560 for south Asia).

Loss of women’s rights is particularly egregious. In Africa, young girls are frequently coerced into sex with HIV-fearing or infected men. In southeast Asia, where HIV is increasingly spread by intravenous drug use, trafficking of young girls has become an economic mainstay, underpinning the cost of drugs as well as the support of displaced, impoverished families. As forced sex workers become infected, they in turn spread the virus to their clients and relations.

Well-meaning but ill-advised

Strong political leadership and investment in HIV prevention can be effective. Thailand and Uganda have dramatically reduced the rate of new infections by openly educating the public and making barrier protection, particularly condoms, widely known, acceptable and available. The potential benefits of some outside investments, like America’s President’s Emergency Plan for AIDS Relief (PEPFAR), however well intended, are undermined by the conditions attached to them.

First, recipients are asked for duplicative and incompatible reports. More worryingly, there is an ideological and political insistence that abstinence be a facet of prevention in cultures where young women have little choice in the matter of sexual relations. There is a further guideline that one-third of all funds be channelled through faith-based institutions whose leaders admit they are uncomfortable talking about condoms. These donor-driven obstacles guarantee that these investments will be far less effective than they otherwise might be.

There is only a decade left to reach the UN’s health millennium development goals to reduce the under-five mortality rate by two-thirds, reduce maternal mortality by three-quarters and halt (and begin to reverse) the spread of HIV/AIDS, malaria and other major diseases.

These targets can be achieved without “magic” new technologies, like an HIV or malaria vaccine (although these would certainly help). But even with new technology, the task remains daunting, and each year the world falls further behind. Political chaos, poverty, insecurity and trampling on human rights preclude both the stable infrastructural platforms (drinkable water, education and nutrition) required to curb these problems in the first place and the means for delivering the direct health interventions that help.

The 40 million people already infected with HIV will die prematurely; even earlier than necessary because of our inability to distribute medication. Obstacles to better health for far too many include political chaos and instability; rampaging thugs and armies trampling on human rights, particularly those of women; cultural taboos and ossified, millennia-old customs; stigmatization; and the absence of anything resembling health care delivery systems.

Brain drain

The inadequacy of health care systems has received relatively little attention. It is not only the result of inadequate investment. The demand for health services has skyrocketed in wealthy and poor countries alike, generating a migration of trained health workers from poor African (or Asian) countries to wealthier ones, and from these to Europe and America, whose demand for trained health personnel is insatiable. The poorest countries are doomed to come off worst in this competition for talent.

The government of Botswana, global pharmaceutical company Merck, and the Bill and Melinda Gates Foundation launched a pioneering effort to demonstrate how medications could be effectively delivered to a highly HIV-infected population (one-third of Botswana’s adults are HIV positive). Even this small, relatively well-to-do country (with a population of 2 million), found its health delivery infrastructure wholly incapable of performing the task. The obstacles have now been removed, but only by diverting manpower from other health goals and by attracting trained workers from poorer countries with equivalent needs. In any case, the real test of any HIV/AIDS programme is not the number of infected people treated, but a decline in the numbers of newly infected.

The UN millennium health goals will remain well beyond our grasp until globally sustainable levels of societal wellbeing are achieved. Human rights, security, education, nutrition and poverty alleviation, particularly among child-rearing women, provide the foundation on which direct health investments can prosper. By the same token, healthy populations are more productive. They can afford to invest in their own health systems and have the power and rationale to secure human rights, invest in their own security and education, and provide vigorous markets for the products of others.

Alfred Sommer
Alfred Sommer is dean of the Johns Hopkins Bloomberg School of Public Health and professor of ophthalmology, epidemiology and international health. He has received numerous awards, including the Albert Lasker Award for Clinical Research and the Charles A Dana Award for Pioneering Achievements in Health. Sommer is a member of the National Academy of Sciences and its Institute of Medicine.