Colonization and infection by Serratia species in a paediatric surgical intensive care unit.

Serratia species are known for the infections they cause in adult and neonatal intensive care patients. Little is known about colonization and infection in paediatric intensive care patients. This study aims to describe the type of infections in critically ill newborns, infants and children, caused by Serratia spp., to compare patients colonized by Serratia spp. to patients colonized with other micro-organisms, and to assess the importance of the respiratory and digestive tracts as reservoirs. To this end, all microbiological samples taken from patients in our paediatric surgical intensive care unit between January 1986 and November 1993 were retrieved from the hospital database and patient records reviewed. Serratia spp. were isolated 1356 times from 97 patients. Eighty-five infections were diagnosed in 40 patients. Infections of the respiratory tract occurred most frequently (n= 65), followed by septicaemia (13), urinary tract infections (3), omphalitis (2), meningitis (1) and conjunctivitis (1). Colonization by Serratia spp. was associated with yearly age at admission, long ICU stay and high mortality. Both the respiratory and digestive tracts were frequently colonized. Our findings do not support the contention that the digestive tract is more important as reservoir than the respiratory tract in neonates. Copyright 2001 The Hospital Infection Society.