Contents - Previous - Next


Energy cost of communicable diseases in infancy and childhood


Abstract
1. Introduction
2. Variation in morbidity from infectious disease
3. Effects of infection on energy status

3.1. Anorexia
3.2. Decreased dietary thermogenesis
3.3. Cultural and therapeutic practices
3.4. Malabsorption
3.5. Metabolic effects
3.6. Fever
3.7. Additional intestinal loss
3.8. Anabolic responses during infection
3.9. Reduced growth and weight loss

4. Reduced activity
5. Energy requirements for recovery from infection
6. Anabolic response
References
Discussion (summarized by B. Schürch)


N.S. SCRIMSHAW *

* Massachusetts Institute of Technology, Cambridge, MA, and Food, Nutrition and Development Programme, United Nations University, Tokyo, Japan.

Abstract

The adverse effects of communicable disease on energy status result from decreased intakes due to anorexia and the tendance to withdraw solid foods, from decreased absorption when the gastrointestinal tract is affected, from increased metabolism due to fever, from increased catabolic losses due to the stress response, and from diversion of energy for the internal synthesis of globulins and other proteins in response to infection. Among underprivileged children in most developing countries, episodes of infectious disease are frequent, and their cumulative effects contribute significantly to impaired growth and development. Energy requirements for recovery, including catch-up growth, are accordingly increased, but they are spread over a longer period of time. Under developing country conditions there is a risk that the diet will be inadequate for rapid recovery, and that another infection will occur before recovery is complete.

1. Introduction

It is well known that infections, no matter how mild, affect both energy intakes and energy requirements through a number of mechanisms (SCRIMSHAW, TAYLOR and GORDON, 1968). In developing countries the presence of an infection is more likely than lack of available food to be responsible for undernutrition. This is equally true in a hospital situation in the United States. In both, however, the quantity and quality of food available to the individual is likely to be the limiting factor during the recovery period. At this time there is a period of increased appetite, and recovery is rapid if the diet is adequate.

The problem in generalizing about the magnitude of the effect of infection on energy requirements is that it depends on the nature, duration and severity of the infection for which the estimate is made. Moreover, for young children in developing country populations, it is not the effect of a single episode that is significant, but the pattern of frequent infections without full recovery between episodes. The failure to recover may be due either to an insufficient diet or to a new infection closely following the previous illness. The issue is complicated by the fact that a poorly nourished child is more likely to have frequent infections and to become still more malnourished as a result. Moreover, the same social and environmental circumstances that make malnutrition likely also increase the probability of frequent exposure to infection.

As summarized in Table 1, the potential effects of infection on energy requirements are variable and complex. Fever associated with an infection would increase energy expenditure while reduced physical activity would decrease it. Anecdotally and by personal observation, this does occur although quantitative documentation is lacking. In addition, even infections that are not associated with fever result in decreased food intake. They also cause a catabolic response that is particularly significant for protein requirements and contributes to energy depletion through this mechanism.

Table 1. Potential effects of infection on energy status

Mechanism

Relative magnitude

Decreased intake:



Anorexia

+ +


Altered diet

+

Decreased absorption:



Acute diarrhea

+


Tropical jejunitis

+


Intestinal parasites

0 or +

Increased requirements:



Greater protein catabolism

+


Protein-losing enteropathy

+


Fever

+, + +


Internal synthesis

+

Decreased requirements:



Reduced activity

-, - -


Reduced growth

-


Less diet-induced thermogenesis


The challenge is to move beyond these conceptual and qualitative statements, to give some idea of the magnitude of the effect of infection on energy requirements under various conditions. Because the nature and circumstances surrounding each infectious episode are different, the relative significance of these effects and their cumulative impact on energy requirements will vary greatly.

2. Variation in morbidity from infectious disease

It is an epidemiological truism that disease morbidity varies with time, place, and person. All this means is that in some places infections may be highly prevalent and in others less so. Even within the same place, overall morbidity and the kinds of infections responsible change over time. Finally, there is great variability among individuals, even at the same time and place. The first step is to identify representative burdens of morbidity as a basis for estimating the effect of infection under any given set of circumstances.

Figures 1 to 3 from Guatemala (MATA, 1978), Mexico (CHAVEZ and MARTINEZ, 1982), and The Gambia (ECCLES et al., 1989), respectively, illustrate the high frequency of infections in young children under village conditions in developing countries. Table 2 provides evidence for the frequency of infections among infants in The Gambia. Each episode of infection is associated with adverse nutritional consequences ranging from mild to severe.

Figure 1. Weight, infections and infectious diseases in a male child. Top: Solid line represents weight of child; broken line is median of the standard. Length of each horizontal line indicates duration of infectious disease. Each mark shows a week positive for the particular infectious agent. Bottom: Observed weight increments (vertical bars) and expected median increments of the standard (dots). (MATA et al. 1971)

Figure 2. The non-supplemented, from the third to the fifth semester, have some illness for as much as half the time. Teozonteopan, Mexico. (CHAVEZ and MARTINEZ, 1979)

Figure 3. The changes in sleeping and metabolic rate (SMR) and body weight with time. Blocks represent the duration of acute episodes of infection. (URTI: upper respiratory tract infection; UTI: urinary tract infection). Gambia. (ECCLES, COLE and WHITEHEAD, 1989)

Table 2. Number of episodes of each illness and the number of days involved for 7 infants in rural Gambia

Illness (episodes/d)

Infant

1

2

3

4

5

6

7

URTI +

6/31

1/3

6/29

1/6

3/24

2/11

3/24

Tonsilitis

1/5

-

1/6

-

2/7

-

-

Otitis media

2/11

8/50

2/8

-

2/11

6/35

1/5

Pneumonia

2/9

-

-

-

2/9

-

1/3

Diarrhea *

3/17

2/18

7/39

1/7

-

2/17

1/12

Diarrhea & vomiting *

-

1/4

1/11

1/4

1/5

1/16

1/5

Vomiting *

-

-

-

-

-

-

1/6

Malaria

1/3

-

1/3

-

-

-

-

Abscess

1/6

-

-

-

1/7

-

-

UTI +

-

-

-

-

1/6

-

-

Fever

2/9

-

3/17

1/7

4/17

1/5

-

All illnesses

18/91

12/75

21/113

4/24

16/86

12/84

8/55

+ URTI = Upper respiratory tract infection; UTI = Urinary tract infection
* Grouped in the analysis as 'gastro-enteritis'.
(ECCLES, COLE and WHITEHEAD, 1989)

Table 3 shows that children in Guatemala who have had measles in preceding weeks have a marked loss of lean body mass compared with children in the same village who did not experience this disease (INCAP, unpublished data). Figure 4 illustrates the devastating effect of whooping cough in a poorly nourished Guatemalan who required 26 weeks after onset of the disease for her weight to return to that before the onset, leaving the child further retarded in weight for age (MATA, 1978). Table 4 shows that, of 44 cases of whooping cough in his village, 25% of the children required more than 25 weeks to regain initial weight, and only one-third recovered in 8 weeks or less. The effect of diarrheal infections on weight gain is shown in Figure 5 (MARTORELL et al., 1975). The degree of deficit in growth increment is proportional to the number of days ill with diarrhea in children 0- to 7-years-old.

Table 3. Effect of measles on CHI index in children in Guatemalan village compared with children with kwashiorkor from the region

Village children

.90-1.00

Children with recent measles

.70-.80

Kwashiorkor

.60 -.70

CHI = Creatine per cm ht (unpublished INCAP data)

Table 4. Time required to recover the weight lost from a single episode of whooping cough

Weeks

N

%

0-4

6

14

5-8

8

18

9-12

8

18

13-16

4

9

17-24

7

16

25 +

11

25

Total

44

100

(INCAP, 1968)

Figure 4. Deterioration of the nutritional status of female child after an attack of whooping cough. Broken top line corresponds to the INCAP standard; solid line shows the mean weight curve for Cauque children; bottom broken line is observed weights of the child. O = onset of disease; A = weight loss; B = weight gain expected in period equivalent to the length of recuperation if not attacked by the disease. To estimate this amount, the mean weight curve for Cauque children was used; the curve of the child was assimilated to such a curve at the time of onset.

Figure 5. Days ill with diarrhea and growth retardation in stature. 134 children, 0-7 years, in rural Guatemalan villages.

In most developing country populations, the close relationships among poverty, malnutrition, poor sanitation and hygiene, and the high prevalence of infections act synergistically to increase the risk of malnutrition and growth failure.

While infectious disease prevalence rates are high under village conditions in developing countries, they are even higher when children are brought together in institutions. Table 5 lists 108 infectious episodes among 34 children in a model convalescent home in Guatemala City with good sanitation and ample room (VITERI, personal communication). Table 6 records 136 episodes among 60 children in a 6-month feeding study in an orphanage in Vellore, India (PEREIRA, personal communication). These are only examples of a universal phenomenon. In addition, children in nurseries, even in industrialized countries, are susceptible to epidemics of a single infection.

Table 5. Acute infections among 32 children aged 2 to 9 years observed in a 'model' convalescent home in Guatemala City for 90 days

Diseases

Total No. episodes

Diseases

Total No. episodes

Infectious hepatitis

2

Gonococcal vaginitis

11

Measles

2

Purulent otitis media

4

Bronchopneumonia

3

Acute tonsillitis

7

Bronchial asthma and asthmatic bronchitis

15

Upper respiratory tract infection

15

Gastroenteritis

5

Fever of unknown origin

9

Amebiasis

9

Urinary infection

1

Parotitis

4

Impetigo and cellulitis

13

Chickenpox

3

Skin allergy

5

Table 6. Illnesses among 60 children aged 2 to 9 years in a 6-month orphanage feeding study in Vellore, South India

Respiratory infections

43

Fever

24

Diarrhea/dysentery

14

Skin infection

47

Jaundice

4

Conjunctivitis

1

Gingivitis

3

Total

136

(PEREIRA, personal communication)


Contents - Previous - Next