An outbreak of salmonellosis associated with a fatality in a healthy child: a large dose and severe illness.

In June 1982, an outbreak of Salmonella gastroenteritis occurred on a farm in Wyoming. All eight affected persons became severely ill 8-18 hours after they had eaten homemade ice cream. A previously healthy 13-year-old boy died 37 hours after exposure; his mother and four younger siblings were transferred to intensive care units in hospitals in adjoining states, and the remaining two adult males were hospitalized locally. Salmonella typhimurium was isolated from all eight ill persons, from the remaining ice cream, and from the family's hens whose eggs were used in the preparation of the ice cream. All Salmonella contained identical plasmids (60-, 5.6-, and 3.3-megadalton); the ice cream contained 10(6) salmonellae/g and, according to food histories, individuals consumed an estimated dose of between 10(8) and 10(9) organisms. The fatal illness occurred in the boy who had eaten the largest amount of ice cream (10(9) organisms). This report demonstrates that Salmonella can cause fatal illness in previously healthy individuals and that the incubation period and the severity of the illness may be related to the dose.