Theresa Madigan

Characteristics and outcomes of outpatient parenteral antimicrobial therapy at an academic children's hospital.

Background: Use of outpatient parenteral antimicrobial therapy (OPAT) in pediatrics is widespread and may be increasing. Recent data quantifying use and characteristics of pediatric OPAT are lacking. Methods: To evaluate the number of children receiving OPAT each year and their associated characteristics and outcomes, we conducted a retrospective review of all patients discharged with OPAT from the Mayo Clinic Children’s Hospital between August 1, 2010 and December 31, 2011. Results: During the study period, there were 126 pediatric hospital discharges with OPAT (2.5% of all discharges). OPAT was used most commonly to treat bone and joint (21%), bloodstream (15%), intra-abdominal (13%) and soft tissue (9%) infections. A positive culture or serology result was found in 86 (68%) OPAT courses. The most frequently used antibiotics were ceftriaxone (17%), cefazolin (16%) and cefepime (13%). The median duration of OPAT was 12 days. Thirty-six courses (29%) resulted in catheter- or antibiotic-associated complications. Weekly laboratory monitoring was more common when OPAT was managed by the infectious disease service (88%) versus other services (20%). Among 123 courses with follow-up, 109 (89%) resulted in cure, and 13 (11%) were treatment failures. Conclusion: At our children’s hospital, 2.5% of hospitalized patients were discharged with OPAT. In one-third of OPAT courses children developed catheter- or antibiotic-associated complications. Opportunities to increase the role of pediatric infectious disease in OPAT initiation and management should be explored.

Extensive Household Outbreak of Urinary Tract Infection and Intestinal Colonization due to Extended-Spectrum β-Lactamase–Producing Escherichia coli Sequence Type 131

BACKGROUND Reasons for the successful global dissemination of multidrug-resistant Escherichia coli sequence type 131 (ST131) are undefined, but may include enhanced transmissibility or ability to colonize the intestine compared with other strains. METHODS We identified a household in which 2 young children had urinary tract infection (UTI) caused by an extended-spectrum β-lactamase (ESBL)-producing, multidrug-resistant ST131 E. coli strain. We assessed the prevalence of ST131 intestinal colonization among the 7 household members (6 humans, 1 dog). Fecal samples, collected 3 times over a 19-week period, were cultured selectively for E. coli. Isolates were characterized using clone-specific polymerase chain reaction to detect ST131 and its ESBL-associated H30Rx subclone, pulsed-field gel electrophoresis, extended virulence genotyping, and antimicrobial susceptibility testing. RESULTS In total, 8 different E. coli pulsotypes (strains) were identified. The index patients urine isolate represented ST131-H30Rx strain 903. This was the most widely shared and persistent strain in the household, colonizing 5 individuals at each sampling. In contrast, the 7 non-ST131 strains were each found in only 1 or 2 household members at a time, with variable persistence. The ST131 strain was the only strain with both extensive virulence and antimicrobial resistance profiles. CONCLUSIONS An ESBL-producing ST131-H30Rx strain caused UTI in 2 siblings, plus asymptomatic intestinal colonization in multiple other household members, and was the households most extensively detected and persistent fecal E. coli strain. Efficient transmission and intestinal colonization may contribute to the epidemiologic success of the H30Rx subclone of E. coli ST131.

The Effect of Age and Weight on Vancomycin Serum Trough Concentrations in Pediatric Patients

Vancomycin treatment failure has been associated with low serum vancomycin trough concentrations, prompting recommendations to increase the daily doses in adults and children. Despite more aggressive vancomycin dosing, there continues to be significant variability in vancomycin trough concentrations in pediatric patients.

Prevalence of rectal colonization with multidrug-resistant Enterobacteriaceae among international patients hospitalized at Mayo Clinic, Rochester, Minnesota.

Rectal colonization with multidrug-resistant Enterobacteriaceae was found in 23 of 94 consecutively enrolled international patients hospitalized at Mayo Clinic, Rochester, Minnesota. No carbapenemase producers were detected. Twenty-one isolates were extended-spectrum β-lactamase-producing Escherichia coli. Colonization was associated with gastrointestinal disease and central venous catheter placement within the antecedent year.

Optimization of vancomycin dosing in very low-birth-weight preterm neonates.

OBJECTIVE To compare vancomycin serum trough concentrations and 24-hour area under the serum concentration-versus-time curve (AUC24) among very low-birth-weight (VLBW) premature infants before and after implementation of an institution-wide increase in neonatal vancomycin dosing. STUDY DESIGN We performed a retrospective analysis of vancomycin concentrations among preterm VLBW neonates before (2007-2010) and after (2010-2013) implementation of a new vancomycin dosing protocol consisting of increased vancomycin daily dose and frequency of administration. RESULTS Neonates weighing < 1,500 g and receiving the new vancomycin dosing regimen had lower rates of undetectable trough concentrations (24 vs. 50%, p = 0.04), higher median trough concentrations (10.8 vs. 5.9 µg/mL, p = 0.003), a higher proportion of goal trough concentrations of 10 to 20 µg/mL (35 vs. 4%, p = 0.005), and a significantly higher vancomycin AUC24 (438 vs. 320 mg·h/L, p = 0.004) compared with historical controls. CONCLUSION Increasing the vancomycin daily dose and dosing frequency led to an increase in vancomycin trough concentrations and AUC24, and a decrease in the proportion of undetectable (< 5.0 µg/mL) troughs, without an increase in toxicity among VLBW premature neonates.

Central Nervous System Blastomycosis in Children - A Case Report and Review of the Literature.

We present a 7-year-old boy with chronic meningitis caused by Blastomyces dermatitidis. A review of the literature revealed 32 cases of central nervous system blastomycosis in children between 1983 and 2016, of which 18 represented parenchymal disease of the brain or spinal cord. Blastomycosis affecting the central nervous system is rare but should be considered in children with chronic meningitis.

Whole-genome sequencing for methicillin-resistant Staphylococcus aureus (MRSA) outbreak investigation in a neonatal intensive care unit

OBJECTIVE To evaluate whole-genome sequencing (WGS) as a molecular typing tool for MRSA outbreak investigation. DESIGN Investigation of MRSA colonization/infection in a neonatal intensive care unit (NICU) over 3 years (2014-2017). SETTING Single-center level IV NICU.PatientsNICU infants and healthcare workers (HCWs). METHODS Infants were screened for MRSA using a swab of the anterior nares, axilla, and groin, initially by targeted (ring) screening, and later by universal weekly screening. Clinical cultures were collected as indicated. HCWs were screened once using swabs of the anterior nares. MRSA isolates were typed using WGS with core-genome multilocus sequence typing (cgMLST) analysis and by pulsed-field gel electrophoresis (PFGE). Colonized and infected infants and HCWs were decolonized. Control strategies included reinforcement of hand hygiene, use of contact precautions, cohorting, enhanced environmental cleaning, and remodeling of the NICU. RESULTS We identified 64 MRSA-positive infants: 53 (83%) by screening and 11 (17%) by clinical cultures. Of 85 screened HCWs, 5 (6%) were MRSA positive. WGS of MRSA isolates identified 2 large clusters (WGS groups 1 and 2), 1 small cluster (WGS group 3), and 8 unrelated isolates. PFGE failed to distinguish WGS group 2 and 3 isolates. WGS groups 1 and 2 were codistributed over time. HCW MRSA isolates were primarily in WGS group 1. New infant MRSA cases declined after implementation of the control interventions. CONCLUSION We identified 2 contemporaneous MRSA outbreaks alongside sporadic cases in a NICU. WGS was used to determine strain relatedness at a higher resolution than PFGE and was useful in guiding efforts to control MRSA transmission.