Enterobacter sakazakii has caused disease in all age groups. From the age distribution of reported cases it is deduced that infants (children less than 1 year old) are at particular risk. Among infants those at greatest risk for Enterobacter sakazakii infection are neonates (first 28 days), particularly pre-term infants, low birth weight infants or immunocompromised infants. Infants of HIV-positive mothers are also at risk both because they may specifically require infant formula and may be more susceptible to infection. This, and low birth weight, may be of particular concern for some developing countries, where the proportion of such infants is higher than in developed countries .