Karen J. Vigil

Escherichia coli Pyomyositis: An Emerging Infectious Disease among Patients with Hematologic Malignancies

BACKGROUND Pyomyositis is typically caused by gram-positive bacteria, especially Staphylococcus aureus. Few cases of Escherichia coli pyomyositis have been reported, including only 1 involving a patient with a hematologic malignancy. METHODS The clinical microbiology database at The M. D. Anderson Cancer Center (Houston, TX) was reviewed for the period January 2003 through December 2007 to identify cases of E. coli pyomyositis. Clinical characteristics, laboratory and radiologic findings, treatment, and outcomes were recorded. Available isolates underwent phylogenetic group determination, virulence genotyping, multilocus sequence typing, repetitive-element polymerase chain reaction, and pulsed-field gel electrophoresis. RESULTS Six cases of E. coli pyomyositis were identified. All patients were receiving chemotherapy for a hematologic malignancy; 5 were severely neutropenic. Three patients became hypotensive, 2 required intensive care, and 2 (33%) died, despite receiving carbapenem therapy. All E. coli isolates were fluoroquinolone resistant; 55% produced an extended-spectrum beta-lactamase (ESBL). Five of 6 available isolates belonged to phylogenetic group B2, had similar virulence factor profiles, exhibited > 95% similar repetitive-element polymerase chain reaction profiles, and represented sequence type ST131; however, all had unique pulsed-field gel electrophoresis profiles. CONCLUSIONS E. coli pyomyositis has emerged as a serious problem among our patients with hematologic malignancy. It usually is caused by members of E. coli ST131, a recently identified cause of fluoroquinolone-resistant, ESBL-positive E. coli infection worldwide. Awareness of this emerging syndrome and the usual causative agent is important to ensure appropriate management when febrile, neutropenic patients with hematologic malignancy exhibit signs of localized muscle infection.

A multicenter study of pandemic influenza A (H1N1) infection in patients with solid tumors in 3 countries: early therapy improves outcomes.

Pandemic influenza A (hereafter 2009/H1N1) caused significant morbidity and mortality during the 2009 pandemia. Patients with chronic medical conditions and immunosuppressive diseases had a greater risk of complications. However, data regarding the characteristics and outcome of 2009/H1N1 infection in patients with solid tumors are nonexistent. Herein, the authors describe a series of influenza 2009/H1N1 in patients with solid malignancies at 3 major cancer hospitals worldwide.

Analytic Review: Viral Pneumonias in Immunocompromised Adult Hosts

Viral infections have always been considered pediatric diseases. However, viral pneumonia has become an important cause of morbidity and mortality in immuncompromised adults. Improved diagnostic techniques, such as the introduction of highly sensitive nucleic acid amplification tests, have not only allowed us to discover new viruses but also to determine the etiology of viral pneumonia in immunocompromised adult hosts. Unfortunately, only a few antiviral agents are available. Thus, early diagnosis and treatment are crucial to patient outcome. In this article, we review the most common viruses that have been implicated as etiologic agents of viral pneumonia in immunocompromised adults. We discuss the epidemiologic characteristics and clinical presentation of these viral infections and the most appropriate diagnostic approaches and therapies when available.

Multidrug-resistant Escherichia coli bacteremia in cancer patients

BACKGROUND Multidrug-resistant (MDR) Escherichia coli is a serious threat to cancer patients. We aimed to determine the risk factors associated with the development of MDR E coli bacteremia in cancer patients and the possibility of horizontal transmission. METHODS We conducted a 1:2 case-control study of 58 patients with MDR E coli bacteremia. The patients demographics, clinical characteristics, and antibiotic use were obtained. MDR E coli was defined as resistant strains to quinolones plus 1 of the following: piperacillin, ceftazidime, or cefepime. Repetitive sequence-based polymerase chain reaction (Rep-PCR) was used to identify DNA interstrain similarities. RESULTS Conditional multiple logistic analysis showed that admission to the hospital within the 30 days prior to infection and chemotherapy use were risk factors for infection with MDR E coli. Rep-PCR showed that, among the MDR E coli strains recovered, 48.6% showed >95% similarity, representing a possible clonal outbreak. Infection control measures were implemented and controlled this horizontal transmission. CONCLUSION Prior admission to the hospital and previous chemotherapy were independent risk factors of acquiring MDR E coli. Molecular fingerprinting techniques detected a possible nosocomial clonal outbreak of MDR E coli, which was aborted through infection control measures.

Valacyclovir: approved and off-label uses for the treatment of herpes virus infections in immunocompetent and immunocompromised adults.

Importance of the field: Herpes viruses are associated with a wide spectrum of clinical diseases and impose considerable morbidity and even mortality in immunosuppressed hosts. Although there is no cure for these conditions, available treatments alleviate symptoms, suppress recurrences and reduce the risk of transmission. Valacyclovir was discovered in 1988 and revolutionized the treatment of these infections by virtue of its less frequent dosing regimen, which promotes patient adherence. Areas covered in this review: This review focuses on the basic principles, mechanisms of action, safety and approved and off-label usage of valacyclovir in the immunocompetent and immunocompromised host. What the reader will gain: The reader will have available the current and most up-to-date information on the pharmacology of valacyclovir as well as its clinical use. Take home message: Valacyclovir is a great alternative for the treatment of herpes infections. Now that its patent has expired, new cheaper formulations may start to appear.

Absence of XMRV in peripheral blood mononuclear cells of ARV-treatment naïve HIV-1 infected and HIV-1/HCV coinfected individuals and blood donors.

Background Xenotropic murine leukemia virus-related virus (XMRV) has been found in the prostatic tissue of prostate cancer patients and in the blood of chronic fatigue syndrome patients. However, numerous studies have found little to no trace of XMRV in different human cohorts. Based on evidence suggesting common transmission routes between XMRV and HIV-1, HIV-1 infected individuals may represent a high-risk group for XMRV infection and spread. Methodology/Principal Findings DNA was isolated from the peripheral blood mononuclear cells (PBMCs) of 179 HIV-1 infected treatment naïve patients, 86 of which were coinfected with HCV, and 54 healthy blood donors. DNA was screened for XMRV provirus with two sensitive, published PCR assays targeting XMRV gag and env and one sensitive, published nested PCR assay targeting env. Detection of XMRV was confirmed by DNA sequencing. One of the 179 HIV-1 infected patients tested positive for gag by non-nested PCR whereas the two other assays did not detect XMRV in any specimen. All healthy blood donors were negative for XMRV proviral sequences. Sera from 23 HIV-1 infected patients (15 HCV+) and 12 healthy donors were screened for the presence of XMRV-reactive antibodies by Western blot. Thirteen sera (57%) from HIV-1+ patients and 6 sera (50%) from healthy donors showed reactivity to XMRV-infected cell lysate. Conclusions/Significance The virtual absence of XMRV in PBMCs suggests that XMRV is not associated with HIV-1 infected or HIV-1/HCV coinfected patients, or blood donors. Although we noted isolated incidents of serum reactivity to XMRV, we are unable to verify the antibodies as XMRV specific.

Carbapenem‑resistant Lactobacillus intra‑abdominal infection in a renal transplant recipient with a history of probiotic consumption

BackgroundLactobacillus sp. is a low virulence bacterium, which rarely causes infection in immunocompetent individuals and usually is considered a contaminant. Normally this organism is susceptible to β-lactam antibiotics, yet resistant strains have been reported.Case presentation and discussionHere, we report a case of a 60-year-old renal transplant recipient who developed an intra-abdominal abscess which grew a carbapenem-resistant Lactobacillus casei. This is significant since it is the first report of a clinical isolate of Lactobacillus sp. that demonstrated both microbiological and clinical resistance to carbapenem use. Moreover, the probiotic supplement that the patient had taken also grew a similar organism raising the concern of probiotic associated infection in immunocompromised individual.

Outpatient Infection Prevention: A Practical Primer

Abstract As more patients seek care in the outpatient setting, the opportunities for health care–acquired infections and associated outbreaks will increase. Without uptake of core infection prevention and control strategies through formal initiation of infection prevention programs, outbreaks and patient safety issues will surface. This review provides a step-wise approach for implementing an outpatient infection control program, highlighting some of the common pitfalls and high-priority areas.

Systemic Delays in the Initiation of Antiretroviral Therapy for Clinically Eligible HIV-Infected Patients in Houston, Texas: The Providers’ Report Card

Background: The current US HIV treatment guidelines support initiation of antiretroviral therapy (ART) for persons with HIV for personal health benefits and prevention of HIV transmission. However, high levels of adherence to ART are critical to maximize individual and public health benefits. We examined the nonclinical barriers to ART initiation for clinically eligible individuals and the provider- and patient-related factors associated with these barriers among HIV-infected patients in Houston/Harris County, Texas. Methods: We analyzed data obtained from a probability sample of HIV medical care providers (HMCPs) in 13 outpatient facilities in Houston/Harris County, Texas surveyed between June and September 2009. We used an inductive thematic approach to code HMCP responses to an open-ended question that asked the main reasons why providers may delay initiating ART for clinically eligible patients. Results: The reasons cited by providers for delaying ART for clinically eligible patients were adherence (42.5%; 95% confidence interval [CI]: 28.5-57.8), acceptance (30%; 95% CI: 18.1-45.4), and structural concerns (27.5%; 95% CI: 16.1-42.8), with significant variations (P < .0001) noted across patients’ race/ethnicity and transmission category. HIV medical care providers with 6 to 10 years’ experience in HIV care and those providing medical care for more than 100 patients monthly were about 4 times (adjusted odds ratio [aOR]: 3.80; 95% CI: 1.20-5.92; P = .039) and 10 times (aOR: 10.36; 95% CI: 1.42-22.70; P = .019) more likely to state adherence and acceptance concerns, respectively, as reasons for delaying ART for clinically eligible patients. Conclusion: Our findings highlight the fact that clinical guidelines are only a starting point for medical decision-making process and that patients themselves play an important role. HMCP access to referrals for other medical issues, support services, and treatment education may help improve adherence and patient readiness for ART, thereby avoiding systemic delays.

Sources of clinical information used in HIV care and treatment: Are providers’ choices related to their demographic and practice characteristics?:

HIV medical care providers need a wide range of evidence-based clinical information resources to manage their patients’ health. We determined whether providers’ choice of information sources for HIV care and treatment are associated with their demographic and medical practice characteristics. Data used for this study were obtained from a probability sample of HIV medical care providers in 13 outpatient HIV facilities in Houston/Harris County, Texas, surveyed between June and September 2009. The mean number of information sources used by HIV medical care providers for HIV care and treatment was 5.83 (95% confidence interval: 4.90–6.75). Antiretroviral therapy guidelines (95.6%), medical journals and textbooks (82.6%), and Internet sources (69.5%) were ranked first, second, and third as sources of clinical information. At least one of the providers’ demographic or medical practice characteristics was significantly (p ⩽ 0.05) associated with six of the clinical information sources. Integration of these information resources into clinicians’ workflow may enhance efficiency of HIV care and treatment and facilitate improved patients’ care and health outcomes.