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Host and Pathogen Factors for Clostridium difficile Infection and Colonization

BACKGROUND Clostridium difficile infection is the leading cause of health care-associated diarrhea, and the bacterium can also be carried asymptomatically. The objective of this study was to identify host and bacterial factors associated with health care-associated acquisition of C. difficile infection and colonization. METHODS We conducted a 15-month prospective study in six Canadian hospitals in Quebec and Ontario. Demographic information, known risk factors, potential confounding factors, and weekly stool samples or rectal swabs were collected. Pulsed-field gel electrophoresis (PFGE) was performed on C. difficile isolates to determine the genotype. Levels of serum antibodies against C. difficile toxins A and B were measured. RESULTS A total of 4143 patients were included in the study; 117 (2.8%) and 123 (3.0%) had health care-associated C. difficile infection and colonization, respectively. Older age and use of antibiotics and proton-pump inhibitors were significantly associated with health care-associated C. difficile infection. Hospitalization in the previous 2 months; use of chemotherapy, proton-pump inhibitors, and H(2) blockers; and antibodies against toxin B were associated with health care-associated C. difficile colonization. Among patients with health care-associated C. difficile infection and those with colonization, 62.7% and 36.1%, respectively, had the North American PFGE type 1 (NAP1) strain. CONCLUSIONS In this study, health care-associated C. difficile infection and colonization were differentially associated with defined host and pathogen variables. The NAP1 strain was predominant among patients with C. difficile infection, whereas asymptomatic patients were more likely to be colonized with other strains. (Funded by the Consortium de Recherche sur le Clostridium difficile.).

Clostridium difficile Infections in a Canadian Tertiary Care Hospital before and during a Regional Epidemic Associated with the BI/NAP1/027 Strain

ABSTRACT Since 2002, an epidemic of Clostridium difficile infections has occurred in southern Quebec, Canada. At Hôpital Maisonneuve-Rosemont, Montreal, Quebec, Canada, the incidence of C. difficile infections increased from 11/1,000 admissions (1999 to 2002) to 27/1,000 admissions (2003 to 2005). We compared the exposures and outcomes for patients infected with strains with different ribopatterns isolated before (n = 55) and during (n = 175) the epidemic, as well as the in vitro activities of antibiotics against those isolates. During the preepidemic period, 46 isolates (84%) were of ribotype 001, 1 was of ribotype 027, and 8 were of other ribopattern types. During the epidemic period, ribotype 027 strains accounted for 140 (80%) isolates; 26 (15%) were of ribotype 001, and 7 were of other ribopattern types. Ribotype 027 strains were highly resistant to fluoroquinolones (FQs) but were susceptible to clindamycin. A pattern of prior specific antibiotic exposure that selected for antibiotic-resistant ribotype C. difficile infections was observed for FQs (ribotype 027) and clindamycin (ribotype 001). The rate of mortality was higher among older patients, those with a high Charlson comorbidity index, and those with longer previous hospitalizations. By multivariate analysis, patients infected with ribotype 027 were twice as likely to die within 30 days of diagnosis than patients infected with other ribotypes (adjusted odds ratio, 2.06; 95% confidence interval, 1.00 to 4.22). The observations from this study support the notion that continued selective antibiotic pressure resulted in the superimposition of the hypertoxigenic ribotype 027 clone on top of the prior dominant ribotype 001 clone in a setting of preexisting high endemicity, thus leading to the high rates of morbidity and mortality seen in the Quebec outbreak. Stringent antibiotic stewardship measures, combined with aggressive infection control, are required to curtail the epidemic of C. difficile infections.

Lack of Emergence of Cytomegalovirus UL97 Mutations Conferring Ganciclovir (GCV) Resistance following Preemptive GCV Therapy in Allogeneic Stem Cell Transplant Recipients

ABSTRACT Fifty allogeneic stem cell transplant recipients were enrolled in a prospective cytomegalovirus pp65 antigenemia-guided preemptive therapy trial. Among these, 10 of 34 patients who received ganciclovir exhibited sustained and/or recurrent antigenemia despite treatment. Thirteen leukocyte preparations from these 10 subjects were screened for the presence of the most frequent cytomegalovirus UL97 mutations conferring ganciclovir resistance. None of these mutations were detected after mean and median ganciclovir exposures of 31.6 and 28.0 days, respectively.

High incidence of herpes zoster in nonmyeloablative hematopoietic stem cell transplantation.

Although the use of nonmyeloablative (NMA) hematopoietic stem cell transplantation (HSCT) regimens has expanded in the past decade, little data exist to support antiviral prophylaxis to prevent herpes zoster (HZ) in recipients who are seropositive for varicella-zoster virus in this population. The present study examined the clinical features, incidence, and risk factors for HZ in a homogeneous cohort of NMA allogeneic HSCT recipients. We conducted a retrospective cohort study assessing all patients who underwent sibling NMA HSCT at Maisonneuve-Rosemont Hospital (Montreal) between July 2000 and December 2008. All patients received the same conditioning regimen, immunoprophylaxis, and graft-versus-host disease therapy. The diagnosis of HZ was defined clinically. Factors associated with HZ were identified using a Cox proportional hazards model. A total of 179 patients were followed for a median of 33 months (interquartile range, 21-59). HZ developed in 66 patients (37%) at a median of 8.3 months post-HSCT; the incidence rate was 175 cases/1000 person-years. The estimated cumulative HZ incidence was 27% at 1 year, 36% at 2 years, and 44% at 3 years. Thoracic dermatomes were most frequently involved (30%); dissemination occurred in 5 patients. No deaths resulted from HZ, but 23% of patients developed postherpetic neuralgia. In multivariate analysis, reactivation of cytomegalovirus and herpes simplex virus was associated with a reduced likelihood of HZ (hazard ratio, 0.54 and 0.33, respectively). Antiviral prophylaxis or treatment for cytomegalovirus and herpes simplex virus reactivations were protective against HZ. The incidence of HZ in our cohort of NMA HSCT recipients is similar to the incidence reported in HSCT recipients who received a myeloablative conditioning regimen. Given the observed high risk, we conclude that recommendations for antiviral prophylaxis should apply, at least for the first year, to the NMA HSCT population as well.

Predictors of asymptomatic Clostridium difficile colonization on hospital admission

BACKGROUND Clostridium difficile (CD) is the leading cause of health care-associated diarrhea and can result in asymptomatic carriage. Rates of asymptomatic CD colonization on hospital admission range from 1.4%-21%. The objective of this study was to evaluate host and bacterial factors associated with colonization on admission. METHODS The Consortium de recherche québécois sur le Clostridium difficile study provided data for analysis, including demographic information, known risk factors, and potential confounding factors, prospectively collected for 5,232 patients from 6 hospitals in Quebec and Ontario over 15 months from 2006-2007. Stool or rectal swabs were obtained for culture on admission. Pulsed-field gel electrophoresis was performed on the isolates. The presence of antibody against CD toxins A and B was measured. RESULTS There were 212 (4.05%) patients colonized with CD on admission, and 5,020 patients were not colonized with CD. Multivariate logistic regression analysis showed that hospitalization within the last 12 months, use of corticosteroids, prior CD infection, and presence of antibody against toxin B were associated with colonization on admission. Of patients colonized on admission, 79.4% had non-NAP1, non-NAP2 strains. CONCLUSION There are identifiable risk factors among asymptomatic CD carriers that could serve in their detection and provide a basis for targeted screening.

Case Report: Legionella pneumophila Lung Abscess in a Patient with Systemic Lupus Erythematosus

ABSTRACT Lung abscess is an infrequently reported complication of Legionella pneumophila pneumonia associated with a high mortality rate. The risk factors, natural course, optimal method of diagnosis, and optimal therapy of this complication are not well defined. One case of Legionella pneumophila lung abscess occurring in a patient with systemic lupus erythematosus is described, and the reports of 26 other cases are reviewed. This complication is usually hospital-acquired and occurs predominantly in transplant recipients and systemic lupus erythematosus patients treated with corticosteroids with or without a cytotoxic drug. The time interval between the onset of immunosuppressive therapy and infection is usually of several weeks. Progression from pneumonia to abscess formation may be rapid more commonly within an upper lobe. Trans: thoracic aspiration within the abscess cavity may be diagnostic, thus obviating the need for open lung biopsy. The prompt institution of erythromycin 4 gm daily intravenously followed by oral therapy for at least 4 weeks is associated with a high survival rate. Adequate drainage from the abscess cavity must be maintained. Radiologic healing may be slow. Long-term survival without relapse does occur. That the clinical spectrum of Legionella pneumophila infection includes lung abscess has not been sufficiently emphasized. This agent should be considered early in the differential diagnosis of lung abscess.

Hepatitis E: A newcomer to the hepatitis alphabet - Case report and review of the literature

The first Canadian case of hepatitis E is described in a patient who travelled to Asia for a six-month period and spent most of his time in India. Hepatitis E shares some similarities with hepatitis A, notably the mode of transmission and the absence of chronic course. However, a few important differences have been noted, including a higher mortality rate and a high fatality rate in pregnant women. Hepatitis E is very common in developing countries and should be suspected more often in individuals with gastrointestinal complaints returning from endemic areas.

Relevance or performance: potential savings associated with verification of prior results before performing microbiology analysis

OBJECTIVE In an era of rising healthcare expenditures, it is critical to find ways to decrease cost. The objective of this study is to evaluate the number of repeated tests and the associated cost savings in a university-affiliated hospital. METHODS The following 7 microbiology analysis were assessed for nonrepeat testing: HCV antibody, HBV core antibody, CMV IgG, rubella IgG, Treponema pallidum antibodies, Clostridioides difficile toxin detection, and vancomycin-resistant enterococci PCR. Presence of a prior positive result leads to the cancellation of subsequent orders. RESULTS Percentages of not repeated test ranged from 0.1% to 21.4%. Rubella IgG had the highest proportion of unnecessary repeat testing. Total cost savings were estimated at

A comparison of ampicillin-cefotaxime and ampicillin-chloramphenicol in childhood bacterial meningitis: an experience in 55 patients

33,627 for 2016. CONCLUSION Unnecessary repeated microbiologic test can account for a non-negligible part of total volume test. Use of an automated software to detect unnecessary repeated microbiologic test through laboratory information system can generate important savings.