Sharon Krystofiak

A large outbreak of Clostridium difficile‐associated disease with an unexpected proportion of deaths and colectomies at a teaching hospital following increased Fluoroquinolone use

BACKGROUND AND OBJECTIVE Fluoroquinolones have not been frequently implicated as a cause of Clostridium difficile outbreaks. Nosocomial C. difficile infections increased from 2.7 to 6.8 cases per 1000 discharges (P < .001). During the first 2 years of the outbreak, there were 253 nosocomial C. difficile infections; of these, 26 resulted in colectomy and 18 resulted in death. We conducted an investigation of a large C. difficile outbreak in our hospital to identify risk factors and characterize the outbreak. METHODS A retrospective case-control study of case-patients with C. difficile infection from January 2000 through April 2001 and control-patients matched by date of hospital admission, type of medical service, and length of stay; an analysis of inpatient antibiotic use; and antibiotic susceptibility testing and molecular subtyping of isolates were performed. RESULTS On logistic regression analysis, clindamycin (odds ratio [OR], 4.8; 95% confidence interval [CI95], 1.9-12.0), ceftriaxone (OR, 5.4; CI95, 1.8-15.8), and levofloxacin (OR, 2.0; CI95, 1.2-3.3) were independently associated with infection. The etiologic fractions for these three agents were 10.0%, 6.7%, and 30.8%, respectively. Fluoroquinolone use increased before the onset of the outbreak (P < .001); 59% of case-patients and 41% of control-patients had received this antibiotic class. The outbreak was polyclonal, although 52% of isolates belonged to two highly related molecular subtypes. CONCLUSIONS Exposure to levofloxacin was an independent risk factor for C. difficile-associated diarrhea and appeared to contribute substantially to the outbreak. Restricted use of levofloxacin and the other implicated antibiotics may be required to control the outbreak

Epidemiology of Legionella Pneumonia and Factors Associated with Legionella-Related Mortality at a Tertiary Care Center

Legionella pneumophila is an important pathogen that may cause nosocomial and community-acquired pneumonia in patients with normal or altered immunity. The epidemiology of 40 cases of legionella pneumonia in patients hospitalized between 1986 and 1994 was studied. Fourteen patients (35%) were solid organ transplant recipients. The calculated annual incidence of L. pneumophila infection was highest among lung transplant recipients (2.07 cases per 1,000 transplant-years). There was a trend toward reduced mortality rates and less severe disease among transplant patients vs. nontransplant patients: mortality rate, 36% vs. 54%; incidence of intubation, 50% vs. 69%; rate of concurrent infections, 29% vs. 38%; and overall rate of complications, 86% vs. 96%; respectively. In a multivariate analysis, factors independently associated with an increased mortality rate were nosocomial acquisition, need for intubation, formation of lung abscess or cavitation, and presence of pleural effusion. Thus, despite differing host immune responses, the most important prognostic factors affecting the outcome of legionellosis are nosocomial acquisition and the development of pulmonary complications.

Infection control issues after bone marrow transplantation.

Bone marrow transplant recipients are at increased risk of a variety of infections from endogenous and exogenous sources. Various practices, including the use of prophylactic agents and a controlled environment are often employed in the name of infection control. Comparable data are lacking because of non-unified definitions of infection and endpoints. Antibiotic-resistant bacteria and fungi are being isolated more frequently as a result of selective pressure.