Sue Boonlayangoor

Outbreak of Human Adenovirus Type 3 Infection in a Pediatric Long-Term Care Facility—Illinois, 2005

BACKGROUND Human adenovirus type 3 (HAdV-3) causes severe respiratory illness in children, but outbreaks in long-term care facilities have not been frequently reported. We describe an outbreak of HAdV-3 infection in a long-term care facility for children with severe neurologic impairment, where only 3 of 63 residents were ambulatory. METHODS A clinical case of HAdV-3 was defined as fever (temperature, > or = 38.0 degrees C) and either a worsening of respiratory symptoms or conjunctivitis in a resident, with illness onset from June through August 2005. We reviewed medical records; conducted surveillance for fever, conjunctivitis, and respiratory symptoms; and collected nasopharyngeal and conjunctival specimens from symptomatic residents. Specimens were cultured in HAdV-permissive cell lines or were analyzed by HAdV-specific polymerase chain reaction assay. RESULTS Thirty-five (56%) of 63 residents had illnesses that met the case definition; 17 patients (49%) were admitted to intensive care units, and 2 (6%) died. Patients were hospitalized in the intensive care unit for a total of 233 patient-days. Illness onset dates ranged from 1 June through 24 August 2005. Thirty-two patients (91%) had respiratory infection, and 3 (9%) had conjunctivitis. HAdV was identified by culture or PCR in 20 patients. Nine isolates were characterized as HAdV-3 genome type a2. CONCLUSIONS Considering the limited mobility of residents and their reliance on respiratory care, transmission of HAdV-3 infection during this outbreak likely occurred through respiratory care provided by staff. In environments where patients with susceptible underlying conditions reside, HAdV infection should be considered when patients are identified with worsening respiratory disease, and rapid diagnostic tests for HAdV infection should be readily available to help identify and curtail the spread of this pathogen.

Evaluation of FilmArray and Verigene Systems for Rapid Identification of Positive Blood Cultures

ABSTRACT The Verigene tests for Gram-positive and Gram-negative organisms in blood culture and the FilmArray blood culture identification panel were assessed for their ability to identify pathogens from positive blood cultures. Both platforms correctly identified bacteria in 92% of monomicrobial cultures analyzed, with times to identification that were significantly shorter than those for identification from subcultures.

Rapid Identification of Positive Blood Cultures by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry Using Prewarmed Agar Plates

ABSTRACT This study describes an inexpensive and straightforward method for identifying bacteria by matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) directly from positive blood cultures using prewarmed agar plates. Different inoculation methods and incubation times were evaluated to determine the optimal conditions. The two methods using pelleted material from positive culture bottles performed best. In particular, the pellet streak method correctly identified 94% of the Gram negatives following 4 h of incubation and 98% of the Gram positives following 6 h of incubation.

Comparison of Cepheid Xpert® Flu/RSV XC and BioFire FilmArray® for detection of influenza A, influenza B, and respiratory syncytial virus

ABSTRACT The Xpert Flu/RSV XC was compared to the FilmArray respiratory panel for detection of influenza (Flu) A, Flu B, and respiratory syncytial virus (RSV), using 128 nasopharyngeal swabs. Positive agreements were 100% for Flu A and RSV and 92.3% for Flu B. The Xpert may be useful in clinical situations when extensive testing is not required and may serve an important role in laboratories already performing broader respiratory panel testing.

Prospective evaluation of the VITEK MS for the routine identification of bacteria and yeast in the clinical microbiology laboratory: assessment of accuracy of identification and turnaround time.

This study assessed the accuracy of bacterial and yeast identification using the VITEK MS, and the time to reporting of isolates before and after its implementation in routine clinical practice. Three hundred and sixty-two isolates of bacteria and yeast, consisting of a variety of clinical isolates and American Type Culture Collection strains, were tested. Results were compared with reference identifications from the VITEK 2 system and with 16S rRNA sequence analysis. The VITEK MS provided an acceptable identification to species level for 283 (78 %) isolates. Considering organisms for which genus-level identification is acceptable for routine clinical care, 315 isolates (87 %) had an acceptable identification. Six isolates (2 %) were identified incorrectly, five of which were Shigella species. Finally, the time for reporting the identifications was decreased significantly after implementation of the VITEK MS for a total mean reduction in time of 10.52 h (P<0.0001). Overall, accuracy of the VITEK MS was comparable or superior to that from the VITEK 2. The findings were also comparable to other studies examining the accuracy of the VITEK MS, although differences exist, depending on the diversity of species represented as well as on the versions of the databases used. The VITEK MS can be incorporated effectively into routine use in a clinical microbiology laboratory and future expansion of the database should provide improved accuracy for the identification of micro-organisms.

Use of the Accelerate Pheno System for Identification and Antimicrobial Susceptibility Testing of Pathogens in Positive Blood Cultures and Impact on Time to Results and Workflow

ABSTRACT The Accelerate Pheno system uses automated fluorescence in situ hybridization technology with morphokinetic cellular analysis to provide rapid species identification (ID) and antimicrobial susceptibility testing (AST) results for the most commonly identified organisms in bloodstream infections. The objective was to evaluate the accuracy and workflow of bacterial and yeast ID and bacterial AST using the Accelerate Pheno system in the clinical microbiology laboratory. The consecutive fresh blood cultures received in the laboratory were analyzed by the Accelerate Pheno system within 0 to 8 h of growth detection. ID/AST performance, the average times to results, and workflow were compared to those of the routine standard of care. Of the 232 blood cultures evaluated (223 monomicrobial and 9 polymicrobial) comprising 241 organisms, the overall sensitivity and specificity for the identification of organisms were 95.6% and 99.5%, respectively. For antimicrobial susceptibility, the overall essential agreement was 95.1% and categorical agreement was 95.5% compared to routine methods. There was one very major error and 3 major errors. The time to identification and the time to susceptibility using the Accelerate Pheno system were decreased by 23.47 and 41.86 h, respectively, compared to those for the standard of care. The reduction in hands on time was 25.5 min per culture. The Accelerate Pheno system provides rapid and accurate ID/AST results for most of the organisms found routinely in blood cultures. It is easy to use, reduces hands on time for ID/AST of common blood pathogens, and enables clinically actionable results to be released much earlier than with the current standard of care.

Prior antimicrobial exposure and the risk for bloodstream infection with fluconazole-non-susceptible Candida strains

Abstract Candida species are a common cause of bloodstream infection among hospitalized patients. Increasingly these infections are caused by strains resistant to commonly used antifungal agents. The aim of this study was to assess the association between exposure to specific antimicrobial agents and subsequent bloodstream infection with fluconazole-non-susceptible and fluconazole-susceptible Candida strains. A retrospective case-case-control study was performed. From 2002 to 2006, 50 consecutive patients with hospital-acquired bloodstream infection caused by Candida strains not fully susceptible to fluconazole were identified (case group 1). For comparison, 54 patients with fluconazole-susceptible candidaemia (case group 2) and a control group of 104 patients without candidaemia were studied. Models were adjusted for demographic and clinical risk factors. The risk for candidaemia associated with exposure to specific antimicrobial agents was assessed. Piperacillin/tazobactam (odds ratio (OR) 6.8, 95% confidence interval (CI) 1.4–32.2) and ciprofloxacin (OR 8.0, 95% CI 1.5–42.5), but not fluconazole, were significant risk factors for bloodstream infection with fluconazole-non-susceptible Candida. Only ciprofloxacin (OR 7.8, 95% CI 1.2–50.7) was associated with bloodstream infection with fluconazole-susceptible Candida. Despite adjustment for prior exposure to fluconazole, exposure to specific antibacterial agents was associated with hospital-acquired bloodstream infection with fluconazole-non-susceptible Candida.

Comparison of turnaround time and time to oseltamivir discontinuation between two respiratory viral panel testing methodologies

Respiratory infections contribute to many Emergency Department visits and hospitalizations, resulting in a high healthcare burden (Neuzil et al., 2003; Schull et al., 2005). Rapid detection of respiratory pathogens in patients presenting with symptoms of an upper respiratory tract infection is crucial for timely determination of optimal antimicrobial management, avoidance of unnecessary evaluations and implementation of transmission-reducing infection control practices. Rapid viral testing can also result in cost savings to the healthcare system through reduction in Emergency Department boarding time and decreased duration of empiric antiviral therapy (Schull et al., 2005). With increased emphasis on antimicrobial stewardship in hospitals to facilitate improved clinical and economic outcomes with antimicrobial therapy, the implementation of rapid diagnostics for laboratory identification of pathogens is of great interest (Bauer et al., 2014). Multiplex PCR is a highly sensitive molecular method for accurate detection of respiratory pathogens and provides a more rapid turnaround time (TAT) compared with other respiratory viral testing methodologies. Our microbiology laboratory switched from the Luminex xTAG respiratory viral panel (RVP) (http://www.luminexcorp.com), which detects 12 respiratory viruses with an assay time of 8.5 h, performed two to three times per week to the Biofire Diagnostics FilmArray respiratory panel (RP) (http://filmarray.com), which detects 17 respiratory viral and three bacterial targets with an assay time of 1.2 h, performed 24 h a day/7 days per week. We compared the TAT between the two RVPs performed at different frequencies and determined the time to discontinuation of empiric oseltamivir among patients testing negative for influenza. All adult patients with an RVP test result reported between 1 December 2011 and 28 February 2012 performed on Luminex xTAG RVP (two to three times per week) and 1 December 2012 and 28 February 2013 performed on FilmArray RP (24 h a day/7 days per week) were evaluated for mean TAT. The mean TAT for the Luminex xTAG RVP (two to three times per week) between 1 December 2011 and 28 February 2012 (n = 230 assays) was 46.4 h compared with a mean TAT of 3.1 h (P<0.001) for FilmArray RP (24 h a day/7 days per week) between 1 December 2012 and 28 February 2013 (n = 872 assays) (Fig. 1). The mean time to discontinuation of empiric oseltamivir amongst patients with an RVP negative for influenza was 4 and 2 days for the Luminex xTAG RVP (n = 42) and FilmArray RP (n = 75) groups, respectively (P<0.001). The reduction in mean time to discontinuation of empiric oseltamivir resulted in cost savings of ~US

The performance of Luminex ARIES ® Flu A/B & RSV and Cepheid Xpert ® Flu/RSV XC for the detection of influenza A, influenza B, and respiratory syncytial virus in prospective patient samples

34.16 per patient (using a wholesale acquisition cost for oseltamivir of US

Allergic inflammation enhances bacterial sinusitis in mice

8.54 per dose), which during the 2012–2013 peak influenza season would be an overall cost saving of US