Effect of zinc supplementation started during diarrhoea on morbidity and mortality in Bangladeshi children: Community randomised trial

Objective: To evaluate the effect on morbidity and mortality of providing daily zinc for 14 days to children with diarrhoea. Design: Cluster randomised comparison. Setting: Matlab field site of International Center for Diarrhoeal Disease Research, Bangladesh. Participants: 8070 children aged 3-59 months contributed 11 881 child years of observation during a two year period. Intervention: Children with diarrhoea in the intervention clusters were treated with zinc (20 mg per day for 14 days); all children with diarrhoea were treated with oral rehydration therapy. Main outcome measures: Duration of episode of diarrhoea, incidence of diarrhoea and acute lower respiratory infections, admission to hospital for diarrhoea or acute lower respiratory infections, and child mortality. Results: About 40% (399/1007) of diarrhoeal episodes were treated with zinc in the first four months of the trial; the rate rose to 67% (350/526) in month 5 and to > 80% (364/434) in month 7 and was sustained at that level. Children in the intervention cluster received zinc for about seven days on average during each episode of diarrhoea. They had a shorter duration (hazard ratio 0.76, 95% confidence interval 0.65 to 0.90) and lower incidence of diarrhoea (rate ratio 0.85, 0.76 to 0.96) than children in the comparison group. Incidence of acute lower respiratory infection was reduced in the intervention group but not in the comparison group. Admission to hospital of children with diarrhoea was lower in the intervention group than in the comparison group (0.76, 0.59 to 0.98). Admission for acute lower respiratory infection was lower in the intervention group, but this was not statistically significant (0.81, 0.53 to 1.23). The rate of non-injury deaths in the intervention clusters was considerably lower (0.49, 0.25 to 0.94). Conclusions: The lower rates of child morbidity and mortality with zinc treatment represent substantial benefits from a simple and inexpensive intervention that can be incorporated in existing efforts to control diarrhoeal disease.