Malnutrition and infection play a major role in causing the preventable deaths and
disabilities that occur in much of the developing world, especially among young children.
In 1980, approximately 39% of the world's preschool children, 141 million in all,
suffered from some degree of malnutrition. Of these children, 59% lived in southeast
Asia. It is estimated that in India alone 56 million and in Africa and the Middle East
18 to 20 million preschool children are less than 80% of their weight for age.
In 1959, Scrimshaw et al. published a landmark review of the interactions of nutrition
and infection, including a critical evaluation of the vast literature from both animal
and human studies (1).
Clinical immunology has undergone impressive changes over the past decades, significantly
increasing our ability to recognize immunologic abnormalities and permitting
better diagnoses and treatment of many immunologic abnormalities.
Without proper nutrition, the immune system would be deprived of the components
and mechanisms that are needed to generate an effective immune response. Some immunologic
variables are often used as measures of the status of the immune system
and its responsiveness to antigenic challenges, including leukocyte number and mobility,
oxidant balance, protein activity, antibody production, and interleukin release.
The most common relationship between protein-energy malnutrition and infection is
the synergism expressed in the concept of the malnutrition-infection cycle.
In this chapter, I will examine whether infants of low birthweight (LBW) are more
susceptible to infection and to death from infection, than infants of adequate birthweight
(ABW), and briefly compare their immunocompetence.
All mammals can synthesize fatty acids de novo from acetyl coenzyme A. The end
product of the fatty acid synthetase enzyme is palmitic acid (16:0), which can be
elongated to stearic acid (18:0).
This chapter highlights the effects of stress on host immunity to disease and reviews
the new insights gained over the past few years on the potential therapeutic role of
nutrition in altering stress-related disease processes.
Micronutrients, the immune system and resistance to infection form a veritable trinity.
Each one influences the others. Although the influence of diet on risk of infectious
disease has been known for centuries, it is only in the last 25 years that the importance
of impaired immune responses as an intermediate risk factor has been
Nutritional deficiencies contribute to the high incidence of morbidity and mortality
from infectious diseases among children in developing countries. Infectious diseases
(respiratory and diarrheal) are among the leading causes of death in children around
Obesity, anorexia nervosa, and bulimia nervosa are significant public health concerns
affecting a large section of the population; they are even considered to be epidemics.
These disorders have a common problem—the failure to maintain a desirable weight.
It is well established that some infections and parasitic diseases predispose patients
to allergic sensitization and trigger allergic reactions, whereas allergic inflammation
predisposes them to skin and mucosal infections.
Stunted growth in many children from developing countries is caused by the synergistic
effects of infection or inflammation and malnutrition. As has been shown many
times over, children's growth can be impeded through the effects of infection on intake,
metabolism, and partitioning of nutrients.
The cardinal clinical features of systemic infection are fever, anorexia, myalgia, and
lethargy sometimes leading to sleep.
More than 90% of the world's children live in low income countries, where infectious
diseases are the predominant cause of the increased rates of childhood mortality and
morbidity that are typical of these settings (1).
In a longitudinal health and nutrition survey of 3,000 children (birth to 2 years of age)
conducted in the Philippines, length and morbidity data were collected bimonthly
over a 2-year period (1).
Endotoxin infusion into weanling rats causes a classic acute phase response characterized
by profound anorexia, acute weight loss, negative protein balance in skeletal
muscle, and the appearance of acute phase proteins, produced by the liver, in the circulation
Malnutrition and the human immunodeficiency virus (HIV) infection usually overlap
in adults and children. The probability of HIV infection among malnourished
children is much higher than in the general population.
Parasites—protozoans and helminths—are responsible for some of the most common
infections of humans and are particularly prevalent in the wanner countries of the
The dynamic interactions between nutrition, immunity, and infection in infants and
childhood have profound implications on the nutritional well-being of children,
which is a major concern to all health professionals.