Persistent excretion of Salmonella in foreign-born adopted and native Swedish children.

The duration of salmonella excretion in 162 foreign-born adopted children and 132 native Swedish children was studied. Of the adopted children (96% being less than 1 year of age) 54% still excreted salmonella at 12 weeks, 32% at 6 months, and 12% at 1 year after arrival in Sweden. The carrier state was more prolonged in the age group 0-3 months compared to the age group greater than 6 months. In the group of native Swedish children, aged 0-5 years, 18% still excreted salmonella at 12 weeks, 4% at 6 months, and none at 1 year after the gastroenteritis episode. A majority of these children were older than 1 year. Intrafamilial transmission of salmonella seemed to be uncommon. Only 6% of the adopted children infected another family member.