Voriconazole compared with liposomal amphotericin B for empirical antifungal therapy in patients with neutropenia and persistent fever.

BACKGROUND: Patients with neutropenia and persistent fever are often treated empirically with amphotericin B or liposomal amphotericin B to prevent invasive fungal infections. Antifungal triazoles offer a potentially safer and effective alternative. METHODS: In a randomized, international, multicenter trial, we compared voriconazole, a new second-generation triazole, with liposomal amphotericin B for empirical antifungal therapy. RESULTS: A total of 837 patients (415 assigned to voriconazole and 422 to liposomal amphotericin B) were evaluated for success of treatment. The overall success rates were 26.0 percent with voriconazole and 30.6 percent with liposomal amphotericin B (95 percent confidence interval for the difference, -10.6 to 1.6 percentage points); these rates were independent of the administration of antifungal prophylaxis or the use of colony-stimulating factors. There were fewer documented breakthrough fungal infections in patients treated with voriconazole than in those treated with liposomal amphotericin B (8 [1.9 percent] vs. 21 [5.0 percent], P=0.02). The voriconazole group had fewer cases of severe infusion-related reactions (P<0.01) and of nephrotoxicity (P<0.001). The incidence of hepatotoxicity was similar in the two groups. Patients receiving voriconazole had more episodes of transient visual changes than those receiving liposomal amphotericin B (22 percent vs. 1 percent, P<0.001) and more hallucinations (4.3 percent vs. 0.5 percent, P<0.001). Parenteral voriconazole was changed to the oral formulation in 22 percent of the voriconazole group, with a reduction in the mean duration of hospitalization by one day in all patients (P=0.17) but by two days in patients at high risk (P=0.03). CONCLUSIONS: Voriconazole is a suitable alternative to amphotericin B preparations for empirical antifungal therapy in patients with neutropenia and persistent fever.

Persistence of babesiosis for >2 years in a patient on rituximab for rheumatoid arthritis.

We report a patient who was being treated with rituximab for rheumatoid arthritis who developed Babesia microti infection that persisted for 26 months despite prolonged anti-babesia drug therapy. The explanation for the persistence was likely to have been the long-term immunocompromising effects of rituximab, as evidenced by seronegativity for B. microti antibodies that lasted for more than 1 year after onset of infection.

Natural history of colonization with vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus, and resistant gram-negative bacilli among long-term-care facility residents.

OBJECTIVE: To determine the natural history of colonization with vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and resistant gram-negative bacilli among long-term-care facility (LTCF) residents. DESIGN: Observational cohort study. SETTING: A 355-bed LTCF with a ventilator unit and a subacute unit. PARTICIPANTS: Residents with colonization or infection with VRE, MRSA, or resistant gram-negative bacilli housed at the LTCF between December 1, 1999, and February 29, 2000. METHODS: Cultures of clinical and surveillance sites were performed at regular intervals. Charts were reviewed for clinical characteristics associated with clearance of colonization. Kaplan-Meier curves were constructed to analyze the number of days to clearance of colonization. RESULTS: Forty-nine residents had 65 episodes of colonization (27 VRE, 30 MRSA, and 8 resistant gram-negative bacilli). Eighteen (28%) of the episodes cleared. The clearance rate was 2.7 episodes per 1,000 person-days. Clearance occurred significantly more often with resistant gram-negative bacilli colonization compared with VRE or MRSA colonization (6 [75%] vs 12 [21%]; P = .007; relative risk, 4.17; 95% confidence interval, 1.26 to 11.8). There was a trend toward longer use of antimicrobial agents among residents with persistent colonization. Infections occurred most frequently with MRSA. The urinary tract was the most common site of infection. CONCLUSION: Among LTCF residents, colonization with resistant gram-negative bacilli is four times more likely to clear than colonization with VRE or MRSA. Performance of surveillance cultures at regular intervals may reduce the need for contact precautions for LTCF residents with resistant gram-negative bacilli colonization.

Evaluation of dedicated stethoscopes as a potential source of nosocomial pathogens.

OBJECTIVE: To determine whether the ear tips of dedicated stethoscopes (DS) that are used on patients prescribed contact precautions for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus faecium, or multiple antibiotic-resistant Acinetobacter baumannii become contaminated with these micro-organisms. DESIGN: Culture of DS ear tips. SETTING: A 524-bed tertiary care university hospital. METHODS: DS ear tips were inoculated directly onto bacteriologic media and incubated for 48 to 72 hours. Growth of more than 10 colonies from the 2 ear tips collectively was indicative of contamination. RESULTS: Ear tips of 78 DS from 69 patients were cultured. Ear tips from 17% (13/78) of the DS were contaminated with potentially pathogenic bacteria: 2 with S aureus (1 MRSA), 1 with E faecalis, 7 with Acinetobacter species, 2 with Pseudomonas species, 1 with Escherichia coli, and 1 with Moraxella. None of the stethoscope ear tips was contaminated with the same pathogen for which the patient was prescribed contact precautions (95% CI, 0-3.8%). CONCLUSION: Although the ear tips of DS from patients who were prescribed contact precautions for MRSA, vancomycin-resistant E faecium, or multiple antibiotic-resistant A baumannii were not contaminated with the indicated nosocomial pathogen, 94% of the evaluable ear tips were contaminated, including with MRSA (1.3%) and Acinetobacter (11%). Regular disinfection of ear tips of DS between users should be considered.

Analysis of sequences and loci of p44 homologs expressed by Anaplasma phagocytophila in acutely infected patients.

Anaplasma phagocytophila is an obligatory intragranulocytic bacterium that causes human granulocytic ehrlichiosis. Immunodominant 44-kDa outer membrane proteins of A. phagocytophila are encoded by a p44 multigene family. In the present study, expression profiles of p44 genes in the blood of acutely infected patients in the year 2000 were characterized. A single p44 gene was predominantly expressed in peripheral blood leukocytes from one patient, while up to 17 different p44 genes were transcribed without a single majority in the other two patients. The cDNA sequences of the central hypervariable region of several p44 genes were identical among the isolates from the three patients and a 1995 A. phagocytophila isolate. A. phagocytophila was isolated by cell culture from all of the three 2000 patients. Genomic Southern blot analysis of the three 2000 and two 1995 A. phagocytophila isolates with probes specific to the most dominant p44 transcript in each patient showed that the p44 loci in the A. phagocytophila genome were conserved. Analysis of the predicted amino acid sequences of 43 different p44 genes including 19 new sequences found in the present study, revealed that five amino acids were absolutely conserved. The hypervariable region was subdivided into five domains, including three extremely hypervariable central domains. These results suggest that variations in the sequences of p44 are not random but are restricted. Furthermore, several p44 genes are not hypermutatable in nature, based on the conservation of gene sequences and loci among isolates obtained 5 years apart.