Louise-Marie Dembry

Changing Patterns in Neonatal Escherichia coli Sepsis and Ampicillin Resistance in the Era of Intrapartum Antibiotic Prophylaxis

OBJECTIVE. The goal was to determine current trends in Escherichia coli-related early- and late-onset sepsis and patterns of ampicillin resistance in relation to institutional changes in the use of intrapartum antibiotic prophylaxis. METHODS. A retrospective review of data for all infants with E coli sepsis at Yale-New Haven Hospital from 1979 to 2006 was performed. Study periods were based on predominant intrapartum antibiotic prophylaxis practices at Yale-New Haven Hospital, that is, (1) 1979 to 1992 (no formal intrapartum antibiotic prophylaxis), (2) 1993 to 1996 (risk factor-based), and (3) 1997 to 2006 (screening-based). Sepsis rates and patterns of ampicillin resistance were compared. RESULTS. Fifty-three cases of E coli early-onset sepsis and 129 cases of E coli late-onset sepsis were identified over 3 eras. In very low birth weight (<1500 g) infants, increases in E coli early-onset sepsis (period 1: 2.83 cases per 1000 very low birth weight admissions; period 2: 7.12 cases per 1000 very low birth weight admissions; period 3: 10.22 cases per 1000 very low birth weight admissions), intrapartum ampicillin exposure, and ampicillin-resistant E coli were observed. Intrapartum ampicillin exposure was determined to be an independent risk factor for ampicillin-resistant E coli early-onset sepsis. For the first time, a significant increase in E coli late-onset sepsis was observed in preterm infants (period 1: 10.39 cases per 1000 very low birth weight admissions; period 2: 16.01 cases per 1000 very low birth weight admissions; period 3: 21.66 cases per 1000 very low birth weight admissions) and term infants (period 1: 4.07 cases per 1000 admissions; period 2: 4.22 cases per 1000 admissions; period 3: 8.23 cases per 1000 admissions). CONCLUSIONS. Studies to provide a better understanding of potential consequences of intrapartum antibiotic exposure and its contribution to evolving trends in neonatal sepsis are urgently needed.

RENAL AND PERIRENAL ABSCESSES

Our knowledge of the spectrum of renal abscesses has evolved as a result of more sensitive radiologic techniques. The classification of intrarenal abscesses currently includes acute focal bacterial nephritis, acute multifocal bacterial nephritis, renal cortical abscess, renal corticomedullary abscess, and xanthogranulomatous pyelonephritis. The clinical presentation of these entities does not differentiate them, however, and various radiographic studies are helpful in making the diagnosis. The intrarenal abscess is usually treated successfully with antibiotic therapy alone. Antistaphylococcal therapy is indicated for the renal cortical abscess, whereas therapy directed against the common gram-negative uropathogens is indicated for most of the other entities. The perinephric abscess is often an elusive diagnosis, has a more serious prognosis, and is more difficult to treat. Drainage of the abscess and sometimes partial or complete nephrectomy, in addition to antibiotic therapy, are required for resolution.

Approaches to vancomycin-resistant enterococci.

PURPOSE OF REVIEW: This article reviews recent publications regarding new antimicrobial drugs for the treatment of vancomycin-resistant enterococci. RECENT FINDINGS: Newer drugs against vancomycin-resistant enterococci are now available or will soon be available. Quinupristin-dalfopristin, a streptogramin, and linezolid, an oxazolidinone, are effective and safe but only bacteriostatic against enterococi. Bacterial isolates resistant to either antibiotic have been described. Daptomycin, a lipopeptide antimicrobial, has good in-vitro bactericidal activity against enterococci, but very limited clinical data exist regarding the treatment of serious enterococcal infection with this compound. Ramoplanin, the first glycolipodepsipeptide antimicrobial in clinical trials, is not systemically absorbed after oral administration, and is being evaluated for the prevention of bloodstream infection in patients colonized with vancomycin-resistant enterococci. Oritavancin and dalbavancin (both glycopeptides) and tigecycline (a monocycline derivative) are being evaluated in phase II and III trials and are not yet commercially available. SUMMARY: Treatment of vancomycin-resistant enterococci continues to be problematical although these new drugs offer some hope. The rational use of antibiotics, strict guidelines for the use of new compounds, and adherence to infection control practices continue to be essential components of the management of vancomycin-resistant enterococci colonization and infection.

Recommended modifications and applications of the Hospital Emergency Incident Command System for hospital emergency management.

The Hospital Emergency Incident Command System (HEICS), now in its third edition, has emerged as a popular incident command system model for hospital emergency response in the United States and other countries. Since the inception of the HEICS in 1991, several events have transformed the requirements of hospital emergency management, including the 1995 Tokyo Subway sarin attack, the 2001 US anthrax letter attacks, and the 2003 Severe Acute Respiratory Syndrome (SARS) outbreaks in eastern Asia and Toronto, Canada. Several modifications of the HEICS are suggested to match the needs of hospital emergency management today, including: (1) an Incident Consultant in the Administrative Section of the HEICS to provide expert advice directly to the Incident Commander in chemical, biological, radiological, nuclear (CBRN) emergencies as needed, as well as consultation on mental health needs; (2) new unit leaders in the Operations Section to coordinate the management of contaminated or infectious patients in CBRN emergencies; (3) new unit leaders in the Operations Section to coordinate mental health support for patients, guests, healthcare workers, volunteers, and dependents in terrorism-related emergencies or events that produce significant mental health needs; (4) a new Decedent/Expectant Unit Leader in the Operations Section to coordinate the management of both types of patients together; and (5) a new Information Technology Unit Leader in the Logistics Section to coordinate the management of information technology and systems. New uses of the HEICS in hospital emergency management also are recommended, including: (1) the adoption of the HEICS as the conceptual framework for organizing all phases of hospital emergency management, including mitigation, preparedness, response, and recovery; and (2) the application of the HEICS not only to healthcare facilities, but also to healthcare systems. Finally, three levels of healthcare worker competencies in the HEICS are suggested: (1) basic understanding of the HEICS for all hospital healthcare workers; (2) advanced understanding and proficiency in the HEICS for hospital healthcare workers likely to assume leadership roles in hospital emergency response; and (3) special proficiency in constituting the HEICS ad hoc from existing healthcare workers in resource-deficient settings. The HEICS should be viewed as a work in progress that will mature as additional challenges arise and as hospitals gain further experience with its use.

Case-control analysis of endemic serratia marcescens bacteremia in a neonatal intensive care unit

Background:Serratia marcescens is an opportunistic gram-negative rod which typically infects compromised hosts. Objectives: To identify risk factors, signs, and outcomes associated with non-epidemic S marcescens bacteremia in a neonatal intensive care unit (NICU). Methods: The records of infants with S marcescens bacteremia while in the Yale-New Haven Hospital NICU from 1980–2004 were reviewed. A matched case-control study was performed by comparing each case of S marcescens to 2 uninfected controls and 2 cases of Escherichia coli bacteremia. Results: Twenty-five sporadic cases of S marcescens bacteremia were identified. Eleven available isolates were determined to be different strains by pulse field gel electrophoresis. Infants with S marcescens bacteremia had median gestational age and birth weight of 28 weeks and 1235 grams, respectively. Compared to matched, uninfected controls, infants with S marcescens bacteremia were more likely to have had a central vascular catheter (OR = 4.33; 95% CI (1.41 to 13.36)) and surgery (OR = 5.67; 95% CI (1.81 to 17.37)), and had a higher overall mortality (44% vs 2%; OR = 38.50; 95% CI (4.57 to 324.47)). Compared to E coli matched controls, infants with S marcescens bacteremia had later onset of infection (median of 33 days of life vs 10; p<0.001), prolonged intubation (OR = 5.76; 95% CI (1.80 to 18.42)), and a higher rate of CVC (OR = 7.77; 95% CI (2.48 to 24.31)) use at the time of infection. A higher rate of meningitis (24% vs 7%; OR = 3.98; 95% CI (1.09 to 14.50)) was observed with S marcescens bacteremia compared to E coli. Conclusions:S marcescens bacteremia occurs sporadically in the NICU, primarily in premature infants requiring support apparatus late in their hospital course. Associated meningitis is common and mortality high.

Management of a sabià virus-infected patient in a US hospital

OBJECTIVE To describe the hospital precautions used to isolate a Sabiá virus (arenavirus: Arenaviridae)-infected patient in a US hospital and to protect hospital staff and visitors. DESIGN Investigation of a single case of arenavirus laboratory-acquired infection and associated case-contacts. SETTING A 900-bed, tertiary-care, university-affiliated medical center. PATIENTS OR OTHER PARTICIPANTS The case-patient became ill with Sabiá virus infection. The case-contacts consisted of healthcare workers, coworkers, friends, and relatives of the case-patient. INTERVENTION Enhanced isolation precautions for treatment of a viral hemorrhagic fever (VHF) patient were implemented in the clinical laboratory and patient-care setting to prevent nosocomial transmission. The enhanced precautions included preventing aerosol spread of the virus from the patient or his clinical specimens. All case-contacts were tested for Sabiá virus antibodies and monitored for signs and symptoms of early disease. RESULTS No cases of secondary infection occurred among 142 case-contacts. CONCLUSIONS With the frequency of worldwide travel, patients with VHF can be admitted to a local hospital at any time in the United States. The use of enhanced isolation precautions for VHF appeared to be effective in preventing secondary cases by limiting the number of contacts and promoting proper handling of laboratory specimens. Patients with VHF can be managed safely in a local hospital setting, provided that appropriate precautions are planned and implemented.

Matched case-control analysis of polymicrobial bloodstream infection in a neonatal intensive care unit.

OBJECTIVE To compare and contrast the epidemiology of polymicrobial and monomicrobial bloodstream infections (BSIs) in newborn intensive care unit (NICU) patients. DESIGN Retrospective, matched case-control study. SETTING The Yale-New Haven Hospital NICU from 1989 through 2006. SUBJECTS NICU patients with BSIs. METHODS Each neonate with polymicrobial BSI (case patient) was matched to one neonate with monomicrobial BSI (control patient), by birth date, weight, and sex; and univariate and multivariate analyses were performed. RESULTS One hundred five cases of polymicrobial BSI were identified in 102 infants, representing 10% of all neonatal BSIs in our institution. Coagulase-negative staphylococci were the most common organisms recovered from culture. Infants with polymicrobial BSI had later onset of infection than infants with monomicrobial BSI (mean day of life, 37.5 vs 24.0; P<.001). Polymicrobial BSI occurred more frequently among infants with a severe underlying condition than in those without such a condition (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.1-3.2) and among infants requiring an indwelling central venous catheter for a prolonged duration (mean, 16.9 days, compared with 9.8 days for infants with monomicrobial BSI; P=.001). Multivariate analysis revealed that later onset of infection (adjusted OR [aOR], 1.02; 95% CI, 1.00-1.04) and presence of a severe underlying condition (aOR, 1.91; 95% CI, 1.12-3.38) were independent risk factors for polymicrobial BSI. No differences in outcome or mortality were observed. CONCLUSIONS Changes in the microbiology and epidemiology of NICU-related polymicrobial BSI have occurred since the last North American review. In the present study, although differences were observed, most risk factors and outcomes were similar between monomicrobial BSI and polymicrobial BSI. Epidemiologic surveillance is critical to identify trends associated with neonatal polymicrobial BSI, particularly those that may impact preventative strategies, diagnostic measures, and therapeutic interventions.

Web-based training improves knowledge about central line bloodstream infections.

A Web-based training course with embedded video clips for reducing central line-associated bloodstream infections (CLABSIs) was evaluated and shown to improve clinician knowledge and retention of knowledge over time. To our knowledge, this is the first study to evaluate Web-based CLABSI training as a stand-alone intervention.

Conjunctival colonization of infants hospitalized in a neonatal intensive care unit: a longitudinal analysis.

OBJECTIVES To determine the frequency of conjunctival colonization, identify the colonizing flora, and correlate culture results with physical findings in infants in a NICU. DESIGN Surveillance study. SETTING Level III NICU of a large university teaching hospital. PATIENTS All infants admitted for longer than 24 hours during a 26-week period. METHODS Weekly bacterial conjunctival cultures were performed for all infants. The conjunctival appearance at the time of culture was recorded. The frequency, identity, and correlation of culture results with physical findings were determined. RESULTS One thousand ninety-one cultures were performed for 319 infants: 133 (42%) had no positive cultures and 186 (58%) had at least one positive culture. Culture analysis revealed that 411 (38%) were positive and yielded 494 isolates comprising more than 18 bacterial species. Bacteria most commonly isolated included coagulase-negative Staphylococcus (CoNS) (75%), viridans group streptococci (8.7%), Staphylococcus aureus (3.8%), Enterococcus species (2.6%), and Serratia marcescens (2.4%). The frequency of non-CoNS isolates increased significantly during the first 6 weeks of patient hospital stay (6% [1 to 3 weeks] to 12% [4 to 6 weeks]; P = .01), with an increasing trend to 15 weeks (18%). Correlation of bacteriologic results with physical findings demonstrated that infants with non-CoNS isolates exhibited conjunctival edema, erythema, or exudates more frequently than did infants with CoNS alone (30% vs 13%; P = .0001). CONCLUSIONS Conjunctival colonization was common among infants in a NICU. Prolonged hospitalization predisposes to colonization with potentially pathogenic organisms. Physical findings were more likely in patients with non-CoNS conjunctival isolates.

Does health care role and experience influence perception of safety culture related to preventing infections

Growing evidence reveals the importance of improving safety culture in efforts to eliminate health care-associated infections. This multisite, cross-sectional survey examined the association between professional role and health care experience on infection prevention safety culture at 5 hospitals. The findings suggest that frontline health care technicians are less directly engaged in improvement efforts and safety education than other staff and that infection prevention safety culture varies more by hospital than by staff position and experience.