Oral Iron Supplementation and Diarrhoeal Disease in Infants: A Prospective Bacteriological Study

Abstract

The influence of chronic iron intake on the incidence and aetiology of acute diarrhoea was prospectively evaluated in a group of Chilean infants. A total of 430 spontaneously weaned infants, aged 3-12 mths, were fed either iron-fortified (IF) or non-enriched (NE) milk formulae. The 6 mths period of continuous surveillance was accomplished through biweekly home visits by trained nurses. Diarrhoeal episodes were recorded and stool samples obtained from symptomatic and paired asymptomatic infants. Results showed a similar incidence of diarrhoeal disease among infants fed IF and NE formulae (1.38 and 1.27 cases/child/6mths respectively). The isolation rate and pathogen distribution were also similar in both groups, either during diarrhoeal episodes (44 per cent and 45 per cent) or asymptomatic infection (19 per cent and 16 per cent). In addition, the number of diarrhoeal episodes associated with mixed bacterial pathogens or with protracted excretion (> 7 d) was apparently not influenced by the ingestion of ironsupplemented formula. These results suggest that chronic consumption of iron-enriched formula neither enhances the incidence of diarrhoea nor modifies the intestinal bacterial ecology in infants who live in areas with suboptimal sanitary conditions. Keywords: Oral iron supplementation; Infants’ diarrhoea; Bacterial enteropathogens; intestinal ecology.