Introduction

In the 20th century there were dramatic reductions in child mortality and general improvements in child health in Western countries. These resulted from economic development, public health interventions, urbanization, better nutrition, maternal health and education, immunization and advances in health technology and curative care. Child mortality rates have fallen from over 100 per 1000 live births in the UK, North America, Australia, New Zealand, Japan, Scandinavian countries and western Europe at the end of the 19th century, to around 4–5 per 1000 live births at the beginning of the 21st century. The vast majority of the world’s people who live in developing countries have not shared in this prosperity and progress. Although progress is being made in most countries, gross inequity exists, with sub-Saharan African and South Asian countries carrying the greatest burden of child deaths and morbidity.

The World Health Organization (WHO) estimated in 2000 that 10.7 million children under the age of 5 years die annually and 99% of these deaths occur in developing countries. By 2008, the estimated number of deaths had fallen to 8.8 million. Figure 1.2.1 shows the distribution of child mortality globally, the majority of under-5 deaths being concentrated in sub-Saharan Africa and South Asia. In 2010, it is estimated that 26 countries had child mortality rates greater than 100 per 1000 live births, all in sub-Saharan Africa except two, Afghanistan and Haiti. A further 30 countries had under-5 mortality rates above 50 per 1000 live births.

Fig. 1.2.1 The distribution of global child mortality. 1 dot = 5000 annual deaths.

(Source: Black RE, Morris SS, Bryce J 2003 Where and why are 10 million children dying each year? Lancet 361: 2226–2234.)

Child health inequity

Inequity is unfair distribution, and child health has many layers of inequity. Inequity between regions and countries is brought into sharp focus in the 21st century because of globalization and freedom to travel. Countries that are half a day’s flying time away from capital cities in Australia, for example, have child mortality rates 10 times higher than that of non-Indigenous children in Sydney or Melbourne.

Inequity exists also within countries. For example, in Papua New Guinea in 1999 the median child mortality rate was 89 per 1000 live births, but some provinces had under-5 mortality rates as low as 49 and others as high as 164 per 1000 live births. Similarly in Cambodia, the child mortality rates in various provinces ranged from 50 to 229 per 1000 live births. Urban child mortality is generally lower than rural mortality, for example: 43 versus 71 per 1000 live births respectively in South Africa. The neonatal mortality rate in remote mountainous areas of Vietnam is three times higher than in urban areas. In general, the rapid trend towards urbanization has contributed to lower child mortality, but some city slums in developing countries have rates of child disease and death that are higher than their nation’s average.

Income is a major determinant of child mortality risk. In 2003, the average under-5 mortality rate was 123 deaths per 1000 in low-income countries, 39 in lower-middle-income countries and 22 in upper-middle-income countries. In high-income countries the rate was less than 7 per 1000. Within-country income inequity also has a great effect on child mortality risk. Among the poorest quintiles (the poorest 20%) of the populations of Cambodia and Vietnam, child mortality rates are two to three times higher than in the richest quintiles. Equity of income distribution is also an important determinant: countries with low gross domestic product (GDP) but a more even income distribution have much lower rates of mortality than other countries with higher GDP but inequitable income distribution. Maternal education and access to health services are also closely related to child mortality risk.

Disparities exist in the financial, technical and human resources available for child health, globally and within countries, and this is closely related to mortality risk. In 1973, Professor David Morley said of Nigeria: ‘Three quarters of our population are rural, yet three quarters of our medical resources are spent in the towns where three quarters of our doctors live; three quarters of the people die from diseases which could be prevented at low cost, and yet three quarters of medical budgets are spent on curative services.’ Unfortunately, the same is still true today of many developing countries. The doctor : population ratios of many countries are 20 times higher in cities than in rural areas. Differences in health service access between rural and urban populations manifest in disparities of functional outcomes as well as mortality risk. For example, compared to urban children with epilepsy, children with epilepsy in rural Zimbabwe are less likely to receive treatment (63% rural versus 95% urban), have a greater seizure burden (2.3 versus 1 per month) and are more likely to have problems that impair social and educational attainment.

Human resources in low-income countries are being further eroded by the drain of doctors and nurses migrating to richer countries. Human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) has exacerbated this human resources crisis; to implement effective antiretroviral treatment programmes requires increased numbers of trained health workers. However, the cruel irony is that HIV/AIDS is claiming a major proportion of the young population of doctors and nurses in countries, particularly in Africa, that most need effective prevention and treatment programmes.

Research in child health is also disproportionate to the burden of diseases and inequitably distributed. While $73 is spent on health research per disability-adjusted life-year lost (DALY: an index that combines both mortality and disability) for diseases overall and $8.40 is spent on research into HIV, malaria and tuberculosis, only $0.51 per DALY is spent on research into acute respiratory infection and $0.30 per DALY on diarrhoea. Some 86% of scientific publications and 97% of patents are held by 16% of the world (the advanced economies), while the remaining 84% publish a mere 14% of the world’s scientific papers and hold 3% of the world’s patents. Therefore, between countries and for all major diseases, capacities to deal with child health problems are inversely proportional to the magnitude of the problems.

Causes of global child mortality

The major causes of death in children aged under 5 years globally are listed in Table 1.2.1. The percentages vary widely across regions, with skewed distribution in the Africa region. For example, 94% and 89% of the world’s malaria and HIV/AIDS deaths occur in Africa.

Table 1.2.1 Major causes of death in children under 5 years of age globally, with estimates for 2000–2003 and 2008

* The apparent dramatic reduction in pneumonia deaths in 2008 compared with 2000–2003 was highly dependent on data from China, the validity of which is uncertain. Note also that deaths from pertussis and meningitis were reported separately in 2008, and neonatal pneumonia was not specifically reported in 2000–2003 data.

Data from: World Health Organization 2005 The World Health Report 2005 – make every mother and child count. WHO, Geneva, p 190 (http://www.who.int/whr/2005/en/) and Black RE, Cousens S, Johnson HL et al. 2010 Global, regional, and national causes of child mortality in 2008: a systematic analysis. Lancet 375:1969–1987.

More than one-third of children who die in developing countries have moderate or severe malnutrition, and malnutrition is implicated in deaths from diarrhoea (61%), malaria (57%), pneumonia (52%) and measles (45%). However, malnutrition is often under-reported in national statistics and under-recognized in clinical settings where childhood malnutrition is so common as almost to be the norm. The situation is even more complex than Table 1.2.1 suggests: although children often present with a single condition (e.g. acute respiratory infection), those who are most likely to die will often have experienced several other infections in recent months, have more than one infection concurrently (e.g. pneumonia and diarrhoea, or pneumonia and malaria) and have malnutrition with micronutrient (such as iron, zinc or vitamin A) deficiency.

Progress in child mortality globally

Since 1990 there have been substantial reductions in deaths in children under 5 years of age. The child mortality rate was 11.9 million in 1990, 10.6 million in 2000, and one modelled projection for 2010 was 7.7 million, a 35% reduction over 20 years. Now no country has a rate of under-5 mortality more than 200 per 1000 live births, whereas in 2000 there were 10 such affected countries. The causes of this progress are many, but include better coverage of health interventions including immunization, vitamin A, insecticide-treated nets, prevention of parent-to-child transmission of HIV, the beneficial effects of urbanization and improved education for girls. In several low-income countries in sub-Saharan Africa there has been an accelerated decline in child mortality since 2000. One factor behind this is resolution of civil wars, allowing health services to re-establish and enabling basic health, education and community interventions to be more widely accessible. Understanding the broader determinants of child survival is crucial to understanding the potential impact of any intervention and the obstacles to reducing child mortality. A recent analysis of data from 152 countries found that gross national income (GNI) per capita, female illiteracy and income equality predicted 92% of the variance in child mortality. A recent study from the Gambia showed that community and social networks, personal support for caregivers in the home, and financial autonomy were more important determinants of child mortality than access to health services. Several large prospective studies have shown that access to community mothers’ groups which support skills and care-seeking results in fewer neonatal deaths.