The interactions between nutrition, the immune system and infection have much clinical and public health significance (Chandra, 1992). The fact that changes in immune responses occur early in the course of nutritional deficiency has led to the suggestion that immunocompetence can be used as a sensitive functional indicator of nutritional status. In patients with obvious primary or secondary malnutrition, the number of T lymphocytes is a useful measure of response to supplementation therapy. Anergy and other immunological changes correlate with poor outcome, in both medical and surgical patients, if impaired immunity is considered in association with hypoalbuminaemia (Chandra, 1983a,b,c). Opportunist infections occur more frequently among those patients with cancer who are also malnourished. The incidence of complicating infections can be reduced if appropriate preventive and therapeutic nutritional management is carried out in patients with leukaemia. It has been postulated that nutritional deficiency may influence the biological gradient and natural history of human immunodeficiency virus (HIV) infection (Jain and Chandra, 1984). Recent surveys indicate that attention to the nutritional needs of the HIV-infected individual is an important part of the overall management of this life-threatening infection (Subcommittee on Nutrition, 2001). Response to immunization is modulated by the nutritional status of the host, and the protective efficacy of vaccines may be suboptimal in the undernourished individual (Chandra, 1972). Finally, immune responses can be used to define safe upper and lower limits of nutrient intake.
We are now able to outline intervention strategies that will reduce the incidence and adverse health impact of both PEM and infection (Chandra, 1992). We have much of the knowledge needed to improve health; this needs to be supported by political commitment and effective management (see also Tomkins, Chapter 18, this volume). The preventive and intervention measures discussed below are well within the combined resources of the world. Even within the health sector, there are glaring anomalies. We must assign priorities and implement methods to prevent and control contributors to morbidity and mortality.
The major intervention strategies and their relative importance in tackling the twin problems of malnutrition and infection are shown in Fig. 3.8. Improvement in socio-economic status and education and ensuring the availability of sufficient food to every individual will most certainly eliminate much of malnutrition and infection, the two diseases of poverty. Health and self-limitation of family size will usually follow these measures. There is a negative correlation between rates of adult female literacy and infant mortality.
Appropriate weaning foods
Oral rehydration therapy
Clean plentiful water
Nutrition and health education
Fig. 3.8. Intervention strategies to deal with the conjugate problem of malnutrition and infection. The importance of each measure is indicated by the size of letters. (Copyright ARTS Biomedical Publishers 1990.)
Promotion of breast-feeding should be continued. The anti-infective properties of human milk are well known and depend in part upon various cellular and soluble factors, as well as its buffering capacity and several antigen-nonspecific protective factors (see also Brandtzaeg, Chapter 14, this volume). Secretory IgA antibodies against a variety of common pathogens have been found in human milk and correlate negatively with morbidity due to specific diseases, such as cholera (Chandra, 1992). The protective effect is particularly dramatic in underprivileged communities with poor sanitation, inadequate housing and contaminated food and water. Furthermore, breast-feeding contributes to birth spacing, an important factor in both maternal and child health.
More effective immunization programmes against the common communicable diseases are required for the majority of the susceptible population. There are still a large number of children in developing countries who die from or are disabled by preventable infectious diseases. Immunization programmes should include universal coverage of all the population at risk. Moreover, there is a need to develop new vaccines, such as those for malaria, Shigella and Pneumococcus, and to improve the quality of those against typhoid, cholera and tuberculosis. In addition, new methods of vaccine preparation, such as genetic recombination, subunit antigens, synthetic-peptide antigens, anti-idio-types and host-cell receptor-specific vaccines, show great promise. It would be ideal to have a single, stable, efficacious, inexpensive vaccine containing immunizing antigens for several infections, which can be given at birth, be easy to administer and have no serious adverse effects.
Other useful preventive measures include the availability of plentiful clean water and improved sanitation and housing. The early and adequate management of diarrhoea and respiratory infections using oral rehydration solution and antibiotics, respectively, has already proved useful and found applicability worldwide. The early detection of growth faltering, using simple weight and height charts, together with subsequent dietary advice, will reduce the prevalence and severity of malnutrition and its adverse consequences. Lastly, targeted subsidies during times of acute need, such as in famines and wars, and massive campaigns to eliminate specific nutrient deficiencies, such as those of vitamin A, iron and iodine, are justified.
Was this article helpful?
All Natural Immune Boosters Proven To Fight Infection, Disease And More. Discover A Natural, Safe Effective Way To Boost Your Immune System Using Ingredients From Your Kitchen Cupboard. The only common sense, no holds barred guide to hit the market today no gimmicks, no pills, just old fashioned common sense remedies to cure colds, influenza, viral infections and more.