Medscape Medical News 2009. © 2009 Medscape
More than one third of patients in the intensive care unit (ICU) at Henry Ford Hospital, in Detroit, Michigan, were seropositive for cytomegalovirus (CMV), according to a study presented here at the Society of Critical Care Medicine 38th Critical Care Congress.
CMV infection is associated with a longer stay in the ICU and in the hospital, a higher risk of nosocomial infection, and nearly double the mortality rate of ICU patients who are seronegative for CMV, said principal investigator Thomas E. Knuth, MD, MPH, senior surgeon in the Division of Acute Care Surgery at Henry Ford Hospital.
“These were all immune-competent patients,” Dr. Knuth pointed out in an interview with Medscape Critical Care. “We know immunocompromised patients are at risk for CMV infection, but we found that 33% of immune-competent patients in the ICU were seropositive. These were patients who were previously healthy and had no risk factors for CMV.”
“We started to check the prevalence of CMV seropositivity after a 78-year-old previously healthy man was admitted to the ICU with pancreatitis, and subsequently died,” he said. “He was immune competent but was seropositive for CMV.”
Dr. Knuth and colleagues began gathering demographics and risk factors associated with CMV viremia in the ICU. They found that:
- 33% of 120 immune-competent ICU patients were CMV seropositive;
- 20% of the 120 patients developed CMV viremia (more than 1000 copies/mL);
- of 237 ICU patents with fever of more than 72 hours duration, 17% were found to be CMV seropositive; and
- 9 of 15 patients treated with prednisone for collagen vascular disease developed CMV viremia.
“These were essentially healthy people,” Dr. Knuth said. “We were very surprised by our findings.”
Dr. Knuth recommends a 2-pronged pre-emptive and preventive strategy.
His pre-emptive strategy consists of weekly screening of ICU patients with multiple or opportunistic infections who are on steroids, are malnourished, or are neutropenic, and treatment with ganciclovir when CMV copies exceed 500 copies/mL.
His preventive strategy consists of prophylactic ganciclovir for patients with multiple or opportunistic infections who are on steroids, are malnourished, or are neutropenic, with less than 225 ATP ng/mL or a CD4 count below 50.
“Prevention and pre-emption are equally important,” he said. “Both strategies together have been shown to reduce the incidence of CMV disease in transplant recipients, from 60% to 20%.”
Dr. Knuth emphasized that only leukoreduced blood should be used in these patients.
A colleague of Dr. Knuth, Michael Malian, MD, FACS, surgeon in the Department of Acute Care Surgery at Henry Ford Hospital, is studying the prevalence and pathology of Clostridium difficile diarrhea in ICU patients. “I’ll bet a good percentage of those patients have CMV infection,” Dr. Knuth said during a poster session at the meeting.
A word of caution came from Robert Duncan Hite, MD, FCCP, associate professor and director of Medical Intensive Care and Critical Care Research at Wake Forest University School of Medicine, in Winston-Salem, North Carolina.
“You cannot draw a cause–effect relationship with these data,” he told Medscape Critical Care. “A high percentage of the general population have antibodies to CMV due to prior exposure, but that does not mean they are infected. The data presented [by Dr. Knuth] regarding the high rate of positive viral cultures is somewhat surprising and deserves further investigation.”
“The higher mortality rates may be related to other comorbid conditions or therapies, rather than the CMV,” Dr. Hite speculated. “Hopefully, further investigation within this database, using multivariate analysis, will be done to examine the independent predictive value of positive CMV culture.”
“As it currently exists, this abstract should not change practice, as therapy for CMV is of limited effectiveness and does have significant associated toxicity.”
None of the researchers have disclosed any relevant financial relationships.
Society of Critical Care Medicine (SCCM) 38th Critical Care Congress: Abstract 724. Presented February 3, 2009.