||Diarrhoeal diseases remain an important cause of childhood mortality and morbidity in developing countries. Improved case-management of diarrhoea have been recognized by the WHO as a cost-effective tool for improving health. The community based studies presented in this thesis were conducted in Guinea-Bissau, West Africa, and examined potential improvements in the case-management of persistent and acute diarrhoea.
Persistent diarrhoea, which is defined as diarrhoea that lasts at least 14 days, has been recognized as a distinct type of diarrhoeal disease which in particular is associated with increased mortality risk, increased diarrhoea-burden, and an increased risk of nutritional insult. In Study I the rationale for the definition of persistent diarrhoea, the aetiology and risk factors identified in previous studies and the different treatment regimes used in persistent diarrhoea are described. Furthermore, own studies related to the identification and modification of a study diet for the dietary treatment and to the implementation of a dietary treatment algorithm for the management of persistent diarrhoea are presented. In recent years centres in developing countries treating severely malnourished children with persistent diarrhoea have reported good results using simple dietary regimes using locally available foods and vitamin and mineral supplementation. A cross-sectional survey of weaning food was conducted in order to examine traditional weaning practices, to identify suitable types of weaning food and to identify potential bottlenecks in the implementation of a dietary treatment algorithm. Potential bottlenecks as reluctancy to serve a child fatty foods during diarrhoea and infrequent preparation of weaning food were identified. A traditional diet identified in the survey was modified in concordance with the generally accepted requirements to enable catch-up growth which is energy content ~1 Kcal/g and energy from protein of 8-10%. We went on to conduct a controlled study to test an algorithm for the treatment of persistent diarrhoea using locally available foods and vitamin and mineral supplementation. A total of 141 episodes of persistent diarrhoea were enrolled in the study. The control group was offered a clinical and paraclinical examination by a medical doctor. In addition, the treatment group was offered the algorithm until recovery. Both groups showed ponderal catch-up growth, however this was more pronounced in the treatment group. Only the treatment group showed linear catch-up growth. This suggests that persistent diarrhoea, in the scope of the present study that included a median follow-up period of 6 months, have a sustained negative effect on linear and partially on ponderal growth which may lead to stunting and possibly to malnutrition. The weight gain in the treatment group exceeded that of the control group with 61.5 g/week (95% CI: 49.2-73.8) before and 12.5 g/week (95% CI: 7.7-17.3) after recovery. Linear growth in the treatment group exceeded that of the control group with 7.2 mm/year (95% CI: 4.6-9.7) for knee-heel length and 11.8 cm/year (-0.7-24.2, p-value=0.06) for height/length after recovery only. The delay in the linear catch-up growth is biologically plausible as the peak velocity for linear catch-up growth occurs 1 to 3 months later after the initiation of the treatment. The increased growth observed in children with persistent diarrhoea offered the treatment algorithm may be related to a combined, perhaps synergistic, effect of dietary and micronutrient supplementation on the intestinal mucosa, the immunological responses and other growth-related factors.
In the search of an ORS-formulation, that would reduce the duration of the diarrhoeal episode, hospital- and laboratory-studies identified reduced osmolarity ORS (224 mmol/L) as beneficial in comparison to WHO ORS (311 mmol/L). We conducted a randomized controlled study (study II) of 738 episodes of acute diarrhoea comparing the safety and efficacy of reduced osmolarity ORS and WHO ORS. There was no difference in the efficacy of reduced osmolarity ORS and WHO ORS assessed by diarrhoeal episode duration. There was a tendency for the mothers to prefer the reduced osmolarity ORS, but a reduced duration of the diarrhoeal episode was seen among the non-breastfed toddlers (i.e. children aged 12 to 30 months) only (Hazard Ratio=1.50, 95% CI: 1.07-2.09). We conclude, that in this group of children with relatively mild diarrhoea, reduced osmolarity ORS is as efficacious as WHO ORS. One may also contemplate that almost any fluid would have been efficacious in this population of mostly breastfed children with mild episodes of diarrhoea. Further studies, are recommended, particularly in settings where early weaning is common, in order to confirm the effect modification related to breastfeeding status.