Maaike Arts asks why we did not include in our Research Letter other recommendations about Enterobacter sakazakii in infant formulae. We believe that our conclusion "The widespread nature of this micro-organism needs to be taken into account when designing preventive control measures" is the only one justified on the basis of the results we reported. The purpose of our study was to gain a better understanding of the ecology of E sakazakii as a starting point for designing effective control strategies. On the basis of the research we reported, we cannot substantiate the recommendations suggested by Arts. However, we would like to draw readers' attentions to the joint FAO/WHO Expert Workshop on E sakazakii and other micro-organisms in powdered infant formula (held in Geneva, Switzerland, Feb 2-5, 2004)1 as a potential source of information.