Prosthetic-Joint-Associated Bordetella holmesii Infection

Bordetella holmesii is a globally distributed pathogen that is increasingly recognized as a cause of both pertussis-like respiratory infections and invasive disease. In this study, we describe a case of an immunocompetent man who developed B holmesii infection of his femoral prosthesis—the fifth B holmesii orthopedic infection reported in literature to date. This article highlights the potentially underrecognized role of B holmesii in orthopedic infections by reviewing these previously reported cases in the context of the current literature.

Control of norovirus outbreak on a pediatric oncology unit

BACKGROUND

Patients undergoing treatment for cancer with chemotherapy and hematopoietic stem cell recipients are at risk for severe morbidity caused by norovirus (NV).

METHODS

We describe a NV outbreak on the Memorial Sloan Kettering Cancer Center's pediatric oncology unit. Stool testing for diagnosis of NV was performed by real-time polymerase chain reaction (PCR).

RESULTS

Twelve NV cases occurred; 7 were hospital acquired. Twenty-five health care workers reported NV compatible illness. Patient-to-patient transmission occurred once. The practices of the Centers for Disease Control and Prevention were supplemented with electronic surveillance, surrogate screening for NV, and heightened cleaning. Two additional cases occurred after implementation of interventions. Long-term shedding was detected in 2 patients.

CONCLUSION

We describe interventions for controlling NV on a pediatric oncology unit. High-risk chronic shedders pose ongoing transmission risks. PCR is a valuable diagnostic tool but may be overly sensitive. Surrogate markers to assess NV burden in stool and studies on NV screening are needed to develop guidelines for high-risk chronic shedders.

Nasal vestibulitis due to targeted therapies in cancer patients

BACKGROUND AND PURPOSE

Cancer patients treated with targeted therapies (e.g., epidermal growth factor receptor inhibitors) are susceptible to dermatologic adverse events (AEs) including secondary skin infections. Whereas infections such as paronychia and cellulitis have been reported, nasal vestibulitis (NV) has not been described with the use of these agents. The aim of our study was to characterize NV in cancer patients treated with targeted therapies.

METHODS

We utilized a retrospective chart review of cancer patients who had been referred to dermatology and were diagnosed with NV. We recorded data including demographics, referral reason, underlying malignancy, targeted anticancer regimen, NV treatment, and nasal bacterial culture results.

RESULTS

One Hundred Fifteen patients were included in the analysis, of which 13 % experienced multiple NV episodes. Skin rash was the most common reason (90 %) for a dermatology referral. The most common underlying malignancies were lung (43 %), breast (19 %), and colorectal (10 %) cancer. Sixty-eight percent of patients had been treated with an EGFRI-based regimen. Nasal cultures were obtained in 60 % of episodes, of which 94 % were positive for one or more organisms. Staphylococcus aureus was the most commonly isolated organism [methicillin-sensitive S. aureus 43 %; methicillin-resistant S. aureus 3 %].

CONCLUSIONS

We report the incidence and characteristics of an unreported, yet frequent dermatologic condition in cancer patients treated with targeted therapies. These findings provide the basis for additional studies to describe the incidence, treatment, and consequences of this event. A better understanding of NV would mitigate its impact on patients' quality of life and risk for additional dermatologic AEs.

Investigation of Increased Rates of Isolation ofBacillusSpecies

Background.

In 2007–2008, several US hospitals reported summertime increases in the number of clinical blood cultures positive forBacillusspecies, which are common environmental bacteria.

Objective.

To investigate increased rates of isolation ofBacillusspecies from blood cultures, identify risk factors, and recommend control strategies.

Design.

Survey and case-control study.

Setting.

Multiple hospitals, including a cancer center.

Methods.

We surveyed 24 facilities that reported increases. We also conducted a field investigation at a hospital with a high rate, reviewing charts, collecting clinical and environmental isolates, and observing infection control procedures. A case-control study compared inpatient case patients who had any blood culture positive forBacilluswith unmatched control patients who had a blood culture with no growth during June-August 2008.

Results.

Among surveyed facilities, mean monthly rates rose from 25 to a peak of 75Bacillus-positive blood cultures per 10,000 blood cultures performed during the period June-August. At the hospital where the case-control investigation was conducted, for most case patients (75%), theBacillus-positive blood cultures represented contamination or device colonization rather than infection. We enrolled 48 case patients and 48 control patients; in multivariate analysis, only central venous access device use was significantly associated with case status (odds ratio, 14.0;P< .01). Laboratory testing identified at least 12 differentBacillusspecies (non-anthracis) among the isolates. Observation of infection control procedures revealed variability in central line care and blood sample collection techniques.

Conclusions.

Periodic increases in the environmental load ofBacillusspecies may occur in hospitals. Our investigation indicated that at one facility, these increases likely represented a pseudo-outbreak ofBacillusspecies colonizing central venous lines or their accessories, such as needleless connector devices. Vigilant attention should be paid to infection control practices when collecting blood samples for culture, to minimize the risk of contamination by environmental microorganisms.

Clostridium difficile infection after allogeneic hematopoietic stem cell transplant: strain diversity and outcomes associated with NAP1/027

Allogeneic hematopoietic stem cell transplantation (HSCT) recipients are at high risk for developing Clostridium difficile infection (CDI). We studied the incidence, risk factors, NAP1/027 prevalence, and clinical outcomes, including acute lower gastrointestinal graft-versus-host disease (GI GVHD), associated with early CDI in this population. A retrospective review was conducted of patients who underwent allogeneic HSCT at Memorial Sloan Kettering Cancer Center from January 1, 2005 to September 30, 2010. Early CDI was defined as infection occurring from day -10 to day +40 from stem cell infusion. Among 793 patients who received allogeneic HSCTs, early CDI occurred in 11.9%; 56% cases were between day -5 and day +5. Overall incidence was 25.2 cases/10,000 at-risk days. There was a high prevalence of NAP1/027 strains during peak incidence (61% in 2008). NAP1/027 was the most common strain in both adult and pediatric cases (24% and 23%, respectively). CDI was clinically mild, including those due to NAP1/027. Metronidazole was the primary treatment for 91 of 94 patients, 7 of 8 cases refractory to metronidazole had no response to vancomycin, and none was due to NAP1/027. Relapse of CDI was common (31%). The cumulative incidence of GI GVHD in patients with and without early CDI was 6.8% and 8%, respectively (P = .5). Most cases of CDI occurred during conditioning or immediately after transplant. Despite high prevalence of NAP1/027, we found only mild disease. Most patients were treated successfully with metronidazole, irrespective of NAP1/027 status. There was no significant association between early CDI and subsequent development of GI GVHD. This study demonstrates the high incidence of CDI early after allogeneic HSCT with wide diversity among infecting strains. Despite the high prevalence of NAP1/027, the disease is mild but relapses are common. No association was found between CDI and subsequent development of GI GVHD.

Estimating risk of C. difficile transmission from PCR positive but cytotoxin negative cases

Background

The use of molecular methods to diagnose Clostridium difficile infection (CDI) has improved diagnostic yield compared to conventional methods. However, PCR testing can detect colonization and has introduced several practical challenges pertaining to need for treatment and isolation of cases.

Methods

For all new cases detected by real-time PCR, concurrent cytotoxin assay was performed and genetic characterization with MLVA (multi-locus variable number tandem repeat analysis) was done to determine relatedness. We used PCR cycle threshold (Ct) of detection as surrogate marker for bacterial burden in stool.

Results

Overall, 54 cases of CDI were detected during the study period. 42 were concurrently tested by CYT and characterized by MLVA .MLVA analysis revealed marked genetic diversity with no ongoing outbreaks; four cases were due to NAP1 strain. CYT −/PCR + cases had a higher median Ct value of detection compared to CYT+/PCR + cases (28.2 vs 22.5; p = 0.01). Among 25 strains that were genetically related, 9/11 isolates in this dominant cluster were positive by CYT compared to 4/14 in non-dominant clusters (p = 0.02).

Conclusion

CYT−/PCR+ cases contribute to hospital based transmission. However, the risk of transmission of C. difficile from CYT +/PCR+ cases may be higher than those that are CYT−/PCR+.

Hospital-onset Clostridium difficile infection rates in persons with cancer or hematopoietic stem cell transplant: a C3IC network report

A multicenter survey of 11 cancer centers was performed to determine the rate of hospital-onset Clostridium difficile infection (HO-CDI) and surveillance practices. Pooled rates of HO-CDI in patients with cancer were twice the rates reported for all US patients (15.8 vs 7.4 per 10,000 patient-days). Rates were elevated regardless of diagnostic test used.

Central line-associated bloodstream infection surveillance outside the intensive care unit: a multicenter survey

OBJECTIVE

The success of central line-associated bloodstream infection (CLABSI) prevention programs in intensive care units (ICUs) has led to the expansion of surveillance at many hospitals. We sought to compare non-ICU CLABSI (nCLABSI) rates with national reports and describe methods of surveillance at several participating US institutions.

DESIGN AND SETTING

An electronic survey of several medical centers about infection surveillance practices and rate data for non-ICU patients.

PARTICIPANTS

Ten tertiary care hospitals.

METHODS

In March 2011, a survey was sent to 10 medical centers. The survey consisted of 12 questions regarding demographics and CLABSI surveillance methodology for non-ICU patients at each center. Participants were also asked to provide available rate and device utilization data.

RESULTS

Hospitals ranged in size from 238 to 1,400 total beds (median, 815). All hospitals reported using Centers for Disease Control and Prevention (CDC) definitions. Denominators were collected by different means: counting patients with central lines every day (5 hospitals), indirectly estimating on the basis of electronic orders ([Formula: see text]), or another automated method ([Formula: see text]). Rates of nCLABSI ranged from 0.2 to 4.2 infections per 1,000 catheter-days (median, 2.5). The national rate reported by the CDC using 2009 data from the National Healthcare Surveillance Network was 1.14 infections per 1,000 catheter-days.

CONCLUSIONS

Only 2 hospitals were below the pooled CLABSI rate for inpatient wards; all others exceeded this rate. Possible explanations include differences in average central line utilization or hospital size in the impact of certain clinical risk factors notably absent from the definition and in interpretation and reporting practices. Further investigation is necessary to determine whether the national benchmarks are low or whether the hospitals surveyed here represent a selection of outliers.

Relapse versus reinfection: surveillance of Clostridium difficile infection

Molecular typing was used to examine surveillance definitions for recurrent Clostridium difficile-associated diarrhea. Among 102 patients, 85 had a second episode within 8 weeks, 88% of which were relapses. Of 49 second episodes occurring after > 8 weeks, 65% were relapses. Categorization of a recurrent episode occurring after >8 weeks as a new infection may misrepresent the majority of episodes for surveillance.

Emergence of daptomycin-resistant VRE: experience of a single institution

Recent surveillance from US hospitals shows that more than 99.5% of vancomycin-resistant enterococci (VRE) isolates remain susceptible to daptomycin. This report describes emergence of daptomycin-resistant VRE at a major cancer center. The percentage of patients with daptomycin-resistant VRE bacteremia increased from 3.4% in 2007 to 15.2% in 2009 ([Formula: see text]). Without susceptibility data, empiric daptomycin therapy for VRE infections should be used with caution.

Vancomycin-resistant Enterococcus domination of intestinal microbiota is enabled by antibiotic treatment in mice and precedes bloodstream invasion in humans

Bloodstream infection by highly antibiotic-resistant bacteria, such as vancomycin-resistant Enterococcus (VRE), is a growing clinical problem that increasingly defies medical intervention. Identifying patients at high risk for bacterial sepsis remains an important clinical challenge. Recent studies have shown that antibiotics can alter microbial diversity in the intestine. Here, we characterized these effects using 16s rDNA pyrosequencing and demonstrated that antibiotic treatment of mice enabled exogenously administered VRE to efficiently and nearly completely displace the normal microbiota of the small and large intestine. In the clinical setting, we found that intestinal domination by VRE preceded bloodstream infection in patients undergoing allogeneic hematopoietic stem cell transplantation. Our results demonstrate that antibiotics perturb the normal commensal microbiota and set the stage for intestinal domination by bacteria associated with hospital-acquired infections. Thus, high-throughput DNA sequencing of the intestinal microbiota could identify patients at high risk of developing bacterial sepsis.

The changing epidemiology of vancomycin-resistant Enterococcus (VRE) bacteremia in allogeneic hematopoietic stem cell transplant (HSCT) recipients

The impact of the rising prevalence of vancomycin-resistant Enterococcus (VRE) prior to hematopoietic stem cell transplantation (HSCT) and changes in transplant techniques on risk of VREB (VRE bacteremia) early after HSCT is not known. This is a retrospective study of 247 adult patients who underwent allogeneic HSCT in the years 2008 and 2009 at the Memorial Sloan-Kettering Cancer Center. Sixty-eight of 247 (27.5%) patients were VRE colonized on pretransplant screening. VRE was the leading cause of bacteremia in the first 30 days after HSCT; 23 of 43 (53.5%) patients with positive blood cultures had VRE. Only 13 (57%) of the 23 patients with early VREB were colonized with VRE on pre-HSCT screening cultures. Mortality was directly attributable to VRE infection in 9% of patients with early VREB. VRE is emerging as the most common cause of preengraftment bacteremia in patients undergoing allogeneic HSCT, and is associated with substantial mortality. Pre-HSCT screening for VRE with stool cultures will not identify all patients who are at risk for VREB. The use of alternate agents with activity against Gram-positive bacteria for fever and neutropenia early after HSCT should be evaluated further in prospective studies.

2009 H1N1 influenza infection in cancer patients and hematopoietic stem cell transplant recipients

OBJECTIVES

Although usually mild, 2009 H1N1 Influenza has caused up to 6000 deaths in the US. To determine outcome in patients with cancer and/or hematopoietic stem cell transplant (HSCT), we reviewed our recent experience at Memorial Sloan-Kettering Cancer Center (MSKCC).

METHODS

During the initial NYC outbreak (May 19-June 30, 2009), all respiratory samples at MSKCC were tested for 2009 H1N1 influenza by DFA, culture, and RT-PCR. Medical records were reviewed for all cases.

RESULTS

During the 6-week period, 45(11%) of 394 tested patients were diagnosed with 2009 H1N1 Influenza. These included 29(17%) of 167 patients with hematologic conditions compared to 16(7%) of 226 with solid tumors (P < 0.01). 21(22%) of 96 tested HSCT recipients were positive. Cough (93%) and fever (91%) were common. Of 29 patients who were radiographically assessed, 8(27%) had lower airway disease. 17(37%) were hospitalized. None required mechanical ventilation. No deaths were attributed to influenza. All treated patients tolerated antiviral medication.

CONCLUSIONS

2009 H1N1 Influenza caused mild symptoms in most patients with cancer and/or HSCT. None died or required mechanical ventilation. Immunosuppression from cancer or its treatment including HSCT may not be a substantial risk for poor outcome, however further studies are needed to validate our results.