New Orleans, LA—Patients receiving allogeneic hematopoietic stem-cell transplant (HSCT) have high rates of vancomycin-resistant enterococci (VRE) upon admission for transplantation. Compared with autologous transplant recipients, they also have a significantly higher risk for becoming VRE-colonized while awaiting transplant, researchers reported at IDWeek.
IDWeek is the joint annual meeting of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.
“VRE are common causes of bacteremia in HSCT patients, which often occurs during the first episode of fever and neutropenia. Understanding rates of VRE colonization and risk of frequent VRE bacteremia in these patients may inform how we use empirical VRE-active therapy,” said Lily Li, MD, New York-Presbyterian Weill Cornell Medical Center.
At her hospital, patients undergoing transplant are screened for VRE colonization with perianal swabs, but their rates of colonization and subsequent risk for VRE bacteremia were unclear. To better understand their VRE risk, Dr Li and colleagues prospectively assessed VRE colonization upon admission for HSCT and weekly thereafter until neutrophil engraftment. This helped them determine the proportion of patients colonized at admission, and rates of VRE acquisition and bacteremia.
Double the VRE Rates in Allogeneic HSCT Recipients
Of 408 HSCT recipients, 243 received allogeneic transplants and 161 received autologous transplants. Altogether, 85 (21.7%) of 391 evaluable patients were found to be colonized with VRE at admission, with rates higher for allogeneic HSCT recipients. If they were not already colonized, allogeneic HSCT recipients were also more likely to acquire VRE during their transplant hospitalization (Table).
“What’s remarkable is that in our allogeneic population, almost 30% of allogeneic transplant patients were already colonized with VRE, which is higher than we would have expected,” Dr Li said, adding that their higher colonization rate compared with autologous transplant recipients might be explained by their greater “exposure to the healthcare system” while awaiting transplant.
The risk for VRE bacteremia within 30 days after transplantation was significantly greater in allogeneic HSCT recipients who were colonized upon admission (16.4%) than in those not colonized (3.6%; P = .001). For autologous HSCT recipients, however, these differences (5.6% vs 2.2%) were not significant (P = .397), Dr Li reported.
No baseline demographic factors were significantly associated with VRE bacteremia in colonized allogeneic HSCT recipients. The median time from HSCT to VRE bacteremia was 8 days.
Overall, 10.6% of patients colonized upon admission developed a bloodstream infection during their first episode of fever and neutropenia, including 10.4% of the allogeneic group and 11.1% of the autologous group. Some of these patients had received levofloxacin prophylaxis.
“In the setting of levofloxacin prophylaxis, colonized patients are at increased risk for VRE bacteremia.… Knowing your center’s VRE colonization status can direct your empiric therapy. If your rate is high, you might think of alternative treatments for an allogeneic patient’s first episode of fever and neutropenia,” Dr Li concluded.