High Mortality Rate in Hospitalized Patients Who Develop Clostridium Difficile Associated Diarrhea
Sushma Arramraju, M.D., Bijo K. John, M.D., Albert Shalomov, M.D., Zheng-Bo Huang M.D., Moshe Rubin, M.D.
Introduction: The incidence of Clostridium Difficile has markedly increased over the past 10 years with rates as high as 22.5 cases per 100 hospital admissions. This has resulted in a substantial burden on health care expenditure. Recently, there have been reports of increasing virulence and emergence of antibiotic resistant strains throughout the world. There are conflicting results in studies of mortality rates in hospitalized patients who develop Clostridium difficile associated diarrhea (CDAD). A recent study from Israel showed that the crude 28 day mortality rate was 12.4%. The objective of this prospective study was to determine the mortality rate in hospitalized patients who develop CDAD. We studied 30 day mortality rates in 47 sequential hospitalized patients who developed CDAD confirmed by stool toxin assay.
Methods: All patients hospitalized at New York Hospital Queens, a large urban community teaching hospital in New York City, who were found to have toxin positive CDAD between May 1, 2008 - July 1, 2008 were enrolled. These included both patients who had diarrhea on admission as well as those who developed diarrhea during the course of hospitalization. Demographic data, admitting diagnosis, laboratory data and treatment regimens were recorded. Patients were then followed up at 30 days for treatment outcome. All the patients received conventional therapy with either Metronidazole or Vancomycin or both.
Results: Among the 47 enrolled patients 18 (38%) were males and 29 (62%) were females. A majority of patients 32/47 (68%) were older than 75. Females were significantly older (80.5 ± 13.7 vs 65.5 ± 21.2 years old; p= 0.009) based on the Mann-Whitney test. 7 patients were lost to follow up. Of the 40 patients followed for 30 days, 17/40 (42.5%) died and 23/40 (57.5%) survived. In the surviving patients, 15/23 (65%) had complete resolution of CDAD. Despite the age disparity between males and females, mortality rates were comparable (42.86 and 42.3 percent respectively). Higher mortality rates were noted in patients older than 75, 13/28 (46%), compared to those who were less than 75, 4/12 (33.3%), but this did not reach statistical significance.
Conclusion: Our study of hospitalized patients with CDAD revealed an unexpectedly high 30 day all cause mortality rate of 42.5%. Despite standard treatment with Vancomycin and Metronidazole these mortality rates are considerably higher than those reported in prior studies. This may reflect the increasing virulence of C. difficile.