Nosocomial blood stream infection in Auckland Healthcare hospitals

Abstract

Aim. To report the epidemiology of nosocomial bloodstream infections in Auckland Healthcare Hospitals. Methods. From January 1995 to December 1997 every positive blood culture result was followed up by an infection control nurse who recorded relevant clinical, laboratory and treatment information on a data collection sheet. The clinical significance of each isolate was determined and the most likely source recorded. Results. During the three year study period, there were 1046 nosocomial blood stream infections yielding 1147 isolates. The most common isolates/groups were coagulase negative staphylococal 19%, S. aureus 18%, E. coli 12%, streptococi 10%, other Enterobacteriaceae 10%, Enterobacter spp. 7%, Pseudomonas spp. 5%, anaerobes 2%, and yeasts 4%. The most common sources were: intravascular lines 40%, urinary tract 8%, skin/soft tissue 8%, gastrointestinal 7%, and unknown 25%. The overall results were strongly influenced by the neonatal intensive care unit at National Women's Hospital where 58% of blood stream infections had intravascular-lines as the source and 53% of the isolates were coagulase negative staphylococci. The overall blood stream infection rate was approximately 6/1000 admissions. Rates per 1000 inpatient days for haematology, intensive care, oncology, neonatal and all other patients were 13, 11, 3, 3 and 1 respectively. Conclusions. Surveillance data that are clinically relevant are useful in identifying areas where infection prevention strategies can be implemented. Because of the importance of lines as a source of nosocomial blood stream infections all aspects of line care are reviewed with the aim of reducing these devices as a source of blood stream infection.