Test Significantly Reduces Mortality Associated With Staphylococcus aureus

Clinical data have demonstrated significantly reduced mortality and hospital costs associated with staphylococcal bloodstream infections (BSIs) due to a new nucleic acid test.

The 2.5-hour fluorescence in-situ hybridization (FISH) assay uses fluorescence-labeled peptide nucleic acid (PNA) probes that target the species-specific ribosomal RNA (rRNA) in bacteria and yeast. PNA FISH is a qualitative nucleic acid hybridization assay intended for identification of organisms from blood cultures. Results are visualized using fluorescence microscopy. Fluorescing cells indicate the target species, while no fluorescence indicates another species is present in the positive blood culture.

A group of infectious disease specialists, headed by Shmuel Shoham M.D. presented data from a study of AdvanDx, Inc.'s (Woburn, MA, USA) PNA FISH diagnostic test at the 2007 annual scientific Meeting of the Society for Healthcare Epidemiology of America. The study took place at the Washington Hospital Center (DC, USA), which is the largest hospital in the nation's capital and among the 25 largest hospitals in the United States.

During the study, 202 patients whose blood culture tested positive for Gram-positive cocci (indicating a staphylococcal bloodstream infection) were alternately assigned to a control, or intervention, group. In the intervention group, PNA FISH results and general organism information were relayed to the treating clinician via a call from a hospital liaison, whereas control group patients did not receive a call with PNA FISH results.

According to the study, reporting of PNA FISH results led to an 80% reduction in intensive care unit (ICU)-related mortality due to S aureus BSIs; median hospital cost-savings of US$19,441 per patient; and a 61% reduction in patients receiving antibiotics for coagulase-negative staphylococci (CNS), which is often a blood culture contaminant that leads to unnecessary antibiotic therapy even though the patient does not have a true bloodstream infection.

"Rapid delivery of PNA FISH data from the laboratory to clinicians was associated with reduced mortality in ICU [intensive care unit] patients,” said Dr. Shoham, section of infectious diseases, director, transplant infectious diseases, Washington Hospital Center. There was also a trend toward reduced length of hospitalization in non-ICU patients with S aureus, and in patients with blood cultures growing CNS [coagulase-negative staphylococci], regardless of location within the hospital. AdvanDx, Inc.'s PNA FISH diagnostic tests provide rapid results that enable us to optimize antimicrobial therapy, improve patient outcomes, and reduce hospital costs,” added Dr. Shoham.


Related Links:
AdvanDx, Inc.
Washington Hospital Center