Background The protozoan Cryptosporidium is a leading cause of diarrhoea morbidity and mortality in children younger than 5 years. However , the true global burden of C ryptosporidium infection in children younger than 5 years might have been underestimated in previous quantifications because it only took account of the acute eects of diarrhoea. W e aimed to demonstrate whether there is a causal relation betwee...