An outbreak of vancomycin-resistant Enterococcus faecium in liver transplant recipients

Abstract

Vancomycin-resistant Enterococcus faecium (VREF) has become a significant nosocomial pathogen for immunosuppressed patients. During a 5-month period in 1993, 8 cases of invasive infection with VREF (7 with bacteremia) were identified in liver transplant recipients, half of whom were adults. Epidemiology and microbiology studies were designed to identify the source and to determine the risk factors for this infection. Overall mortality was 50% (3 adults and 1 child). Mortality in bacteremic patients was 57%. A casecontrol study showed that cases were more likely to have been treated with a third-generation cephalosporin or vancomycin and to have undergone more than four biliary tract procedures. Environmental surveillance cultures yielded only one VREF isolate from a rectal temperature probe, but this device was used in only 2 of the cases. Cultures from all surgery and radiology suites were negative. All VREF isolates were genotyped by contour-clamped homogenous electric field electrophoresis of chromosomal DNA restriction fragments. These studies showed that a single clone was responsible for the outbreak, although other clones could be detected in the hospital. After implementing strict contact isolation on the liver transplant unit, only 1 additional patient with VREF was identified during this outbreak. In conclusion, it was found that antibiotic use and biliary tract manipulation were risk factors for developing invasive infections with VREF after liver transplantation. Optimal treatment is still unclear but most likely includes a combination of two or more antibiotics. Prompt institution of infection control measures can preclude rapid spread of this nosocomial pathogen.

Prediction of Poorer Prognosis by Infection With Antibiotic-Resistant Gram-positive Cocci Than by Infection With Antibiotic-Sensitive Strains

“…[10][11][12][13][14] Because of concerns that these issues may have been factors in the study populations of this investigation, immunosuppressed patients who underwent solid-organ transplantation were analyzed separately. Among the 441 study patients, 117 were transplant recipients.…”

Bacterial, mycobacterial, and protozoal infections after liver transplantation—Part I

“…VRE can cause recurrent bacteremia and refractory infection, and the organism can persist at the primary site of infection 60. High death rates in earlier studies60, 63–66 were probably at least partly attributable to inadequate antibiotics 60. Despite the noted clinical differences between vancomycin‐susceptible and vancomycin‐resistant strains, a recent study of enterococcal infections did not find any differences in intensive care unit costs, length of stay in the intensive care unit, or mortality 67…”

“…Risk factors for VRE acquisition include the use of any antibiotics, especially broad‐spectrum antibiotics such as cephalosporins, or vancomycin 63–66. Prolonged antimicrobial use,66 recent infection with vancomycin‐susceptible enterococci,65 and other concurrent infection,64 including any fungal infections or intra‐abdominal infections by any organism,65 are additional risk factors for VRE acquisition.…”

“…VRE colonization can persist for months or years, and VRE infection ensues in about 10% of patients in whom colonization has occurred 68. High rates of colonization among hospitalized liver transplant recipients may be caused by multiple strains or a single clonal outbreak 63. Adherence to infection control measures may limit the spread of VRE to other persons 63.…”

“…High rates of colonization among hospitalized liver transplant recipients may be caused by multiple strains or a single clonal outbreak 63. Adherence to infection control measures may limit the spread of VRE to other persons 63. Susceptible strains of VRE can be treated with linezolid or the combination of quinupristin and dalfopristin.…”