|Oral Rehydration Therapy and the Control of Diarrheal Diseases (Peace Corps, 1985, 566 pages)|
|Module Three: Nutrition and diarrhea|
|Session 7 - Nutrition during and after diarrhea|
The main mechanism by which diarrhoea leads to malnutrition is uncertain and few data exist to clarify the situation. Mike Rowland reports from a long-term study in The Gambia looking into this problem.
Diarrhoea and malnutrition are major causes of childhood morbidity and mortality in less-developed countries. the interaction between the two was highlighted during the early 1960's and an excellent account later published. The complex relationship is still not fully later published.(1) The complex relationship is still not fully understood but two generalizations appear valid.
Failure to thrive
Malnourished children (i.e. children who are failing to thrive) appear to suffer more severe episodes of diarrhoea than their better nourished counterparts(2) and to excrete infective organisms for longer. This situation is complicated by the fact that impaired growth in many of these children may he largely due to the heavy burden of diarrhoea already experienced.
Diarrhoea more than any other infection causes serious growth-faltering in children in many areas of the world. It is significant that in the three continents where this has been well described all mothers in the study communities breastfed their children for long periods. The children would almost certainly have been worse off if fed otherwise but protection is not complete in most subjects(3) nor does breastfeeding preclude serious morbidity in under-privileged communities.
Some workers feel that food shortage in the community plays a relatively minor role in early childhood growth-faltering and that if diarrhoea could be prevented near-normal growth could occur. The main mechanism by which diarrhoea leads to malnutrition is uncertain and few data exist to clarify the situation. Some suggest that anorexia is the main cause, others that malabsorption due to abnormalities of gut flora and function is a more likely explanation.
In The Gambia there is marked seasonal variation in growth and disease in young children and studies there(4) have thrown some light on these problems.
At certain times of the year it appears that normal and even catch-up growth is possible on a traditional diet of locally grown food, provided the individual child suffers little diarrhoea. At other times of the year, however, growth is uniformly depressed whether or not diarrhoea occurs and this tends to be the case in the traditional "hungry season". Thus diarrhoea at different times appears to have an effect on growth of widely differing magnitude.(5) Just as the aetiology may vary from season to season and also from one age-group to another, so may the nature and severity of the pathological processes which follow infection.
In the Gambian community studied diarrhoea is certainly responsible for some reduction in complementary food intake in the weanling child (i.e. the child receiving troth breast milk and additional foods). hut so are a number of other infections which have little or no detectable effect on growth. Furthermore there tare indirect indications that some degree of intestinal malabsorption may be common in the young village children. On balance it appears that in this community at any rate malabsorption is more important than anorexia in explaining diarrhoea-induced growth-faltering.(6)
Weanlings at risk
Whatever the mechanism it seems clear that the initiation of the weaning process, even when breastfeeding is continued for long periods afterwards, puts children at serious risk. This is supported by examination of the weaning foods used. In The gambia the earliest weaning foods are cereal gruels or paps. These are grossly inadequate nutritionally with approximately half the energy-density of breast milk and many of other nutrients are inadequate or totally lacking.
Furthermore it is these earliest foods which show the highest levels of bacterial contamination, both with faecal "marker" organisms and known gut pathogens.(7) Local fuel shortages make it impossible for mothers to cook frequent meals for small children. Instead larger quantities are prepared and kept for long periods, when they may easily become contaminated.
A total approach
In this situation we cannot afford to neglect any health strategy including promotion and active support of the breastfeeding mother, the appropriately timed introduction of hygienically prepared, nutritious weaning foods, the general use of complete oral rehydration mixtures, and various aspects of environmental sanitation. In the course of treating children with diarrhoea, breastfeeding should be maintained and other foods withheld only if there appears to be clinically important intolerance (and not just malabsorption) to these foods.
We may hope for vaccines against a number of diarrhoeal agents in the near future but as title is known of the impact of various individual agents on growth in different communities it would be unwise to try to predict the efficacy of this stage is which, if any, organisms are particularly important in the diarrhoea-malnutrition complex; useful work is already being undertaken along these lines in Bangladesh.(8)
Mike Rowland, Medical Research Council, Fajara,, The Gambia,,
(1) Scrimshaw N S et al Weanling diarrhoea - a synergism of infection and nutrition. Interactions of nutrition and infection WHO Monogram Ser. No 57: 216-261
(2) Tomkins A M 1981 Nutritional status and severity of diarrhoea among pre school children in rural Nigeria. The Lancet, April 18: 860-862
(3) Rowland M G M et al 1980 Bacteriostasis of Escherichia cold by milk. Vl. The in-vitro bacteriostatic property of Gambian mothers' breast milk in relation to the in-vivo protection of their infants against diarrhoeal disease. Journal of Hygiene Cambridge 198085. 405 -4 13
(4) Rowland M C M, Whitehead R G 1978 The epidemiology of protein. energy malnutrition in children in a West African village community. Medical Research Council. Available from Nutrition Planning.
(5) Rowland M G M d al 1977 A quantitative study into the role of infection in, determining nutritional status in Gambian village children. British Journal of Nutrition 197737: 441-450
(6) Rowland M C M 1980 (in press) Interaction between diarrhoea and malnutrition: aetiological considerations. In: Acute enteric infections in children. New prospects for treatment and prevention. Proceedings of Nobel Conference 3.
(7) Rowland M G M e: al 1978 Bacterial contamination in traditional Gambian weaning foods. The Lancet January 21 : 136-138
(8) Black R E 1980 (in press) Epidemiological importance of diarrhoeal agents in Bangladesh. In: Acute enteric infections in children. New prospects for treatment and prevention. Proceedings of Nobel Conference 3.
(From: Diarrhea Dialogue: Issue 6, August 1981, pp. 4-5)