Nosocomial salmonellosis: implications for microbiologic processing of stools in hospitalized patients

A parent as a vector of Salmonella brandenburg nosocomial infection in a neonatal intensive care unit

A newborn baby was admitted to the Neonatal Intensive Care Unit (NICU) of St Germain en Laye Hospital (France) because of premature birth. On day 12, he contracted gastroenteritis due to Salmonella brandenbourg. The salmonellosis led to a septic shock syndrome with a brief cardiopulmonary arrest. He was treated with intravenous ceftriaxone and gentamicin, and the evolution was favorable. Microbiological investigations revealed that the mother was the vector for this nosocomial infection. S. brandenbourg was isolated from the feces of the baby, despite recent recommendations on managing stool specimens from patients hospitalized for more than three days: according to these recommendations, these stools should be processed for viruses and Clostridium difficile toxin only.

The role of Clostridium difficile and viruses as causes of nosocomial diarrhea in children

OBJECTIVE

We report surveillance of nosocomial diarrhea in children at our institution during the past decade and note different epidemiology of diarrhea due to viruses and Clostridium difficile.

DESIGN

A prospective cohort study.

SETTING

A university-affiliated pediatric hospital with 180 beds serving an urban area and providing referral care for the Maritime Provinces of Canada.

PARTICIPANTS

Children younger than 18 years.

METHODS

Surveillance was conducted from 1991 to 1999 using personal contact with personnel and review of microbiology and medical records. Nosocomial diarrhea was defined as loose stools occurring more than 48 hours after admission, with at least two loose stools in 12 hours and no likely non-infectious cause.

RESULTS

Nosocomial diarrhea was the third most common nosocomial infection (217 of 1,466; 15%), after bloodstream and respiratory infections, with from 0.5 to 1 episode per 1,000 patient-days. Of 217 nosocomial diarrhea episodes, 122 (56%) had identified pathogens: C. difficile (39 of 122; 32%), rotavirus (38 of 122; 31%), adenovirus (36 of 122; 30%), and other viral (9 of 122; 7%). The median age was 1.3 years (range, 11 days to 17.9 years), 0.80 year for children with viral diarrhea, 3.9 years for children with C. difficile, and 1.5 years for children with diarrhea without a causative organism identified (P< .0001). Most children with nosocomial diarrhea were incontinent (diapered) at the time of their first episode (138 of 185; 75%), but preexisting incontinence was more common in those with viral diarrhea (93%) compared with those with no organism identified (71%) or those with C. difficile-associated diarrhea (CDAD) (49%) (P <.0001).

CONCLUSIONS

C. difficile is the single most common cause of nosocomial diarrhea in our tertiary-care center, although all viral pathogens account for 69% of cases. Diapered status appears to be a risk factor for CDAD in children, and CDAD occurs more often in older children than viral nosocomial diarrhea. Further characterization of risk factors for, and morbidity associated with, nosocomial CDAD in children is warranted.