Serratia marcescens bacteremia traced to an infused narcotic

BACKGROUND From June 30, 1998, through March 21, 1999, several patients in the surgical intensive care unit of a hospital acquired Serratia marcescens bacteremia. We investigated this outbreak. METHODS A case was defined as the occurrence of S. marcescens bacteremia in any patient in the surgical intensive care unit during the period of the epidemic. To identify risk factors, we compared patients with S. marcescens bacteremia with randomly selected controls. Isolates from patients and from medications were evaluated by pulsed-field gel electrophoresis. The hair of one employee was tested for fentanyl. RESULTS Twenty-six patients with S. marcescens bacteremia were identified; eight (31 percent) had polymicrobial bacteremia, and seven of these had Enterobacter cloacae and S. marcescens in the same culture. According to univariate analysis, patients with S. marcescensbacteremia stayed in the surgical intensive care unit longer than controls (13.5 vs. 4.0 days, PS. marcescens and E. cloacae. The isolates from the case patients and from the fentanyl infusions had similar patterns on pulsed-field gel electrophoresis. After removal of the implicated respiratory therapist, no further cases occurred. Full Text of Results... CONCLUSIONS An outbreak of S. marcescens and E. cloacae bacteremia in a surgical intensive care unit was traced to extrinsic contamination of the parenteral narcotic fentanyl by a health care worker. Our findings underscore the risk of complications in patients that is associated with illicit narcotic use by health care workers

Molecular and Phenotypic Characteristics of Healthcare- and Community-Associated Methicillin-Resistant Staphylococcus aureus at a Rural Hospital

BACKGROUND: While methicillin-resistant Staphylococcus aureus (MRSA) originally was associated with healthcare, distinct strains later emerged in patients with no prior hospital contact. The epidemiology of MRSA continues to evolve. METHODS: To characterize the current epidemiology of MRSA-colonized patients entering a hospital serving both rural and urban communities, we interviewed patients with MRSA-positive admission nasal swabs between August 2009 and March 2010. We applied hospitalization risk factor, antimicrobial resistance phenotype, and multi-locus sequence genotype (MLST) classification schemes to 94 case-patients. RESULTS: By MLST analysis, we identified 15 strains with two dominant clonal complexes (CCs)-CC5 (51 isolates), historically associated with hospitals, and CC8 (27 isolates), historically of community origin. Among patients with CC5 isolates, 43% reported no history of hospitalization within the past six months; for CC8, 67% reported the same. Classification by hospitalization risk factor did not correlate strongly with genotypic classification. Sensitivity of isolates to ciprofloxacin, clindamycin, or amikacin was associated with the CC8 genotype; however, among CC8 strains, 59% were resistant to ciprofloxacin, 15% to clindamycin, and 15% to amikacin. CONCLUSIONS: Hospitalization history was not a strong surrogate for the CC5 genotype. Conversely, patients with a history of hospitalization were identified with the CC8 genotype. Although ciprofloxacin, clindamycin, and amikacin susceptibility distinguished CC8 strains, the high prevalence of ciprofloxacin resistance limited its predictive value. As CC8 strains become established in healthcare settings and CC5 strains disseminate into the community, community-associated MRSA definitions based on case-patient hospitalization history may prove less valuable in tracking community MRSA strains

Household risk factors for colonization with multidrug-resistant Staphylococcus aureus isolates.

Antimicrobial resistance, particularly in pathogens such as methicillin-resistant Staphylococcus aureus (MRSA), limits treatment options and increases healthcare costs. To understand patient risk factors, including household and animal contact, potentially associated with colonization with multidrug-resistant MRSA isolates, we performed a prospective study of case patients colonized with MRSA on admission to a rural tertiary care hospital. Patients were interviewed and antimicrobial resistance patterns were tested among isolates from admitted patients colonized with MRSA in 2009-10. Prevalence of resistance was compared by case-patient risk factors and length-of-stay outcome among 88 MRSA case patients. Results were compared to NHANES 2003-04. Overall prevalence of multidrug resistance (non-susceptibility to ≥ four antimicrobial classes) in MRSA nasal isolates was high (73%) and was associated with a 1.5-day increase in subsequent length of stay (p = 0.008). History of hospitalization within the past six months, but not antimicrobial use in the same time period, was associated with resistance patterns. Within a subset of working-age case patients without recent history of hospitalization, animal contact was potentially associated with multidrug resistance. History of hospitalization, older age, and small household size were associated with multidrug resistance in NHANES data. In conclusion, recent hospitalization of case patients was predictive of antimicrobial resistance in MRSA isolates, but novel risk factors associated with the household may be emerging in CA-MRSA case patients. Understanding drivers of antimicrobial resistance in MRSA isolates is important to hospital infection control efforts, relevant to patient outcomes and to indicators of the economic burden of antimicrobial resistance

Long-term follow-up of post-cardiac surgery Mycobacterium chimaera infections: A 5-center case series

OBJECTIVES: In multiple countries, endovascular/disseminated Mycobacterium chimaera infections have occurred in post-cardiac surgery patients in association with contaminated, widely-distributed cardiac bypass heater-cooler devices. To contribute to long-term characterization of this recently recognized infection, we describe the clinical course of 28 patients with 3-7 years of follow-up for survivors. METHODS: Identified at five hospitals in the United States 2010-2016, post-cardiac surgery patients in the cohort had growth of Mycobacterium avium complex (MAC)/M. chimaera from a sterile site or surgical wound, or a clinically compatible febrile illness with granulomatous inflammation on biopsy. Case follow-up was conducted in May 2019. RESULTS: Of 28 patients, infection appeared to be localized to the sternum in four patients. Among 18 with endovascular/disseminated infection who received combination anti-mycobacterial treatment and had sufficient follow-up, 39% appeared to have controlled infection (>12 months), 56% died, and one patient is alive with relapsed bacteremia. While the number of patients is small and interpretation is limited, four (67%) of six patients who had cardiac prosthesis removal/replacement appeared to have controlled infection compared to three (25%) of 12 with retained cardiac prosthesis (p >0.14; Fisher's exact test). CONCLUSIONS: Given poor response to treatment and potential for delayed relapses, post-cardiac surgery M. chimaera infection warrants aggressive treatment and long-term monitoring

Study design for analysis of risk factors from case-patients interviewed at Penn State Hershey Medical Center.

<p>Study design for analysis of risk factors from case-patients interviewed at Penn State Hershey Medical Center.</p

Antimicrobial resistance by risk factor among MRSA isolates comparing data from NHANES 2003–04 and data from Penn State Hershey Medical Center 2009–10.

<p>Adjusted models include gender, age, hospitalization, and household size.</p

Unadjusted and adjusted prevalence ratios for antimicrobial resistance by risk factor among 88 MRSA isolates from Penn State Hershey Medical Center admitted patients, August 2009 to February 2010.

<p>Intermediates are included with resistant isolates for the SENTRY MDR definition, but are included with the susceptible population for the remainder of the categories. Unadjusted and adjusted results are limited to the 88 individuals for whom complete data on all potential covariates is available. Adjusted models control for gender, age, history of hospitalization, history of antimicrobial use, livestock exposure, household pets, and household size. Prevalence ratios (PRs) shown are estimated from poisson regression models (categorical models used for hospitalization and antibiotic use). Significant associations (two-sided p<0.05) are shown in bold. Associations that are non-significant but approach significance (two-sided p<0.10) are italicized. Race was not included due to small numbers of non-white participants (<i>n</i> = 6).</p>*<p>Household size includes index patient.</p

Risks for antimicrobial resistance in CA-MRSA case-patients of working age (18–65), <i>n = 27.</i>

<p>*<i>p</i><0.10. No estimates were statistically significant at the <i>p</i><0.05 level. ‡ A PR could not be estimated for MDR5 (high multi-drug resistance, 5+ classes of antimicrobial) for household pet presence due to a 0 stratum. Antimicrobial resistance patterns: MDR4: nonsusceptibility to four or more classes of antimicrobial drug; MDR5 (“high multidrug resistance”): high-level (complete) resistance to five or more classes of antimicrobial drug; CIPR: high-level resistance to ciprofloxacin; CLIR: high-level (complete) resistance to clindamycin, including inducible resistance; AMKR: high-level (complete) resistance to amikacin.</p