The Riddle of Malnutrition. Jennifer Tappan

      INTRODUCTION

      The riddle of malnutrition, which proved puzzling to health workers in the East African country of Uganda, as in other world regions, concerned the syndrome now known as severe acute malnutrition. Severe acute malnutrition is the most serious and most fatal form of childhood malnutrition. Global estimates in the early twenty-first century indicate that the condition annually affects between ten and nineteen million children, with over five hundred thousand dying before they reach their fifth birthday.¹ The condition was first recognized, as a form of protein deficiency known as kwashiorkor, in the mid-twentieth century and for a time was a central international concern.² Severe acute malnutrition is currently defined in fairly simple terms, but is far from a simple condition. Children who exhibit “severe wasting” or a weight-for-height ratio that is less than 70 percent of the average for their age are seen to be suffering from severe acute malnutrition. Alternative markers include nutritional edema or very low mid-upper arm circumference measurements. Children diagnosed as severely malnourished require immediate therapy and run a very high risk of succumbing to the condition.³ What is more, recent investigations suggest that even those who do survive appear to suffer from long-term impacts on their overall growth and development.⁴

      Until the late twentieth century, the condition now diagnosed as severe acute malnutrition, or SAM, was thought to be two entirely separate syndromes. Kwashiorkor and marasmus, which are now recognized as extreme manifestations of the same condition, occupy opposing ends along a spectrum of severe malnutrition. Marasmus is defined as undernutrition or frank starvation with the extreme and highly visible wasting of both muscle and fat (see fig I.1). Kwashiorkor, on the other hand, is seen as a form of malnutrition and although the specific cause or set of causal factors that lead to kwashiorkor remain uncertain, kwashiorkor came to be associated with a diet deficient in protein.⁵ In sharp contrast with the very thin appearance of children suffering from marasmus, the most important and consistent symptom of kwashiorkor is edema, or an accumulation of fluid in the tissues, which gives severely malnourished children a swollen and plump, rather than starving, appearance (see fig I.2). This telltale swelling is exacerbated by an extensive fatty buildup beneath the skin and in the liver, and these symptoms long confounded biomedical efforts to understand the condition and connect it to poor nutritional health. Many children with kwashiorkor also develop a form of dermatosis, or rash, in which the skin simply peels away, and they often lose the pigment in their hair. One of the most distressing aspects of the condition is the extent to which children with kwashiorkor suffer. They are visibly miserable, apathetic, and anorexic.

      FIGURE I.1. Marasmus. Source: D. B. Jelliffe and R. F. A. Dean, “Protein-Calorie Malnutrition in Early Childhood (Practical Notes),” Journal of Tropical Pediatrics, December 1959, 96–106, by permission of Oxford University Press.

      The refusal to eat further exacerbates and contributes to an impaired ability to digest food, increasing the high mortality rates associated with severe acute malnutrition, and especially children suffering from kwashiorkor. Prior to the 1950s, case fatality rates in Africa ranged widely but were frequently cited as high as 75 and even 90 percent. Although these mortality rates fell considerably when new therapies were developed, they remained at unacceptably high global rates of between 20 and 30 percent until the twenty-first century. A new set of therapeutic protocols promises to reduce the associated mortality by more than half, but has only inconsistently achieved such rates of recovery and survival. Severely malnourished children who are infected with HIV experience the highest case fatality rates, which may have been a factor contributing to the mortality associated with the condition long before the discovery of HIV in the 1980s.⁶ Moreover, severe acute malnutrition, like undernutrition more broadly, cannot be entirely separated from other forms of debility and disease, as poor nutritional health significantly increases the morbidity and mortality of a wide range of infections including HIV. Despite the “synergistic association” between undernutrition and disease, poor nutritional health is considered the cause of death only when recovery and survival are specifically compromised by the presence of malnutrition. On this basis, global estimates indicate that, taken together, various forms of undernutrition accounted for over three million deaths in children under the age of five in 2011—a figure encompassing an astonishing 45 percent of worldwide infant and child mortality.⁷ The relatively small fraction of under-five mortality that is directly attributed to severe acute malnutrition alone—estimated in 2011 to be approximately 7.4 percent—nonetheless represents more than five hundred thousand children, a death toll on par with malaria.⁸

      FIGURE I.2. Kwashiorkor. Courtesy of Paget Stanfield.

      Like malaria, the prevalence of severe acute malnutrition is concentrated in particular world regions.⁹ The overall global prevalence was estimated in 2011 to be approximately 3 percent, which roughly equates to nineteen million children, with the highest prevalence rates found in central Africa where an estimated 5.6 percent are severely malnourished. Global indications suggest that the prevalence of less severe forms of childhood malnutrition decreased since the 1990s, with Africa as the only exception.¹⁰ Evidence from Uganda, where a 2010 survey found that 2 percent of children were severely malnourished and 6 percent showed signs of less severe wasting, corroborates this trend.¹¹ In the mid-twentieth century, annual prevalence in Uganda was estimated at 1 percent, although statistics from the Ugandan Ministry of Health indicate that, based on the twenty-three thousand to thirty-six thousand children annually diagnosed with malnutrition between 1961 and 1966, the prevalence may have been closer to between 2 and 3 percent.¹² Establishing even estimates of historical prevalence rates must confront a number of significant challenges. Prior to the 1950s, kwashiorkor was not widely recognized as a condition, and in Uganda, biomedical practitioners later equated a number of different locally recognized forms of illness as kwashiorkor.¹³ What is more, prevalence has often been assumed to be more or less static, meaning that, until fairly recently and except when assessing the success of specific interventions, little effort was made to investigate the shifting epidemiology of severe acute malnutrition.¹⁴ The result is that we are left with the knowledge that severe acute malnutrition remains a serious problem in many parts of the world, but have, at best, an incomplete understanding of how prevalence may have shifted over time. This gap in existing knowledge limits efforts to consider the role of contributing factors, including economic and social variables.¹⁵

      In the postwar development era, when betterment schemes promised to lift entire populations out of poverty, severe acute malnutrition in Africa and other global regions did become a central international concern.¹⁶ It not only occupied the attention of biomedical experts and nutritionists, but, due in large part to the jarring images of severely malnourished children that Time Life Magazine published in 1968—photos of children from the refugee camps of Nigeria’s Biafra War—the condition