Lab Matters Summer 2018 | Page 65

APHL 2018 Annual Meeting Poster Abstracts

Presenter: Maureen Diaz, MPH, PhD, Centers for Disease Control and Prevention, Atlanta, GA, Phone: 773.329.5803, Email: iqs5 @ cdc. gov

Evaluating the Flocked Swab as a Tool to Sample and Recover Healthcare Pathogens from Nitrile Gloves

H. Houston 1, L. Rose 1, J. C. Whitworth 1, J. K. Johnson 2, G. Robinson 2, S. Leekha 2, J. Noble-Wang 1; 1 Centers for Disease Control and Prevention, Atlanta, GA, 2 University of Maryland School of Medicine, Baltimore, MD

Flocked swabs are commonly used in healthcare for collecting clinical specimens for diagnosis and surveillance purposes. Manufacturers claim their charged fibers hold and release organisms efficiently, with some claiming superior performance for environmental sampling as well. In working toward developing a standardized, efficient hand and glove sampling and recovery method, we compared the use of a representative nylon flocked swab( eSwab™, Copan Diagnostics, Inc.) to a cellulose sponge, the Sponge Stick( 3M™), as potential glove sampling devices. Nitrile gloves were inoculated with a carbapenem-resistant Klebsiella pneumoniae( KPC), methicillin-resistant Staphylococcus aureus( MRSA) and Clostridium difficile spores( CD) suspended in Artificial Test Soil( Healthmark Industries, Inc.) to simulate body fluids. Inocula( 50 µ l of 104 CFU / mL or 103 CFU / mL for vegetative cells and 105 CFU / mL or 104 CFU / mL for the CD spores) were spread along each of the four fingers and across the top of the palm and allowed to dry for 10 minutes, then sampled with one flocked swab, two flocked swabs, or a Sponge-Stick( SS). Sampling devices were processed, eluents cultured, then enumerated and the percent recovery determined. We saw no significant difference between using one or two swabs to sample a single glove( p > 0.05). The SS performed significantly better than flocked swabs when recovering CD( SS 48.4 %, eSwab 18.3 %; p = 0.05) and KPC using a 104 inoculum( SS 4.5 %, eSwab 1.6 %; p = 0.05). However, there was no significant difference between flocked swabs and SS when recovering MRSA and KPC using a 103 inoculum with the mean recoveries ranging between 8.1 % and 13.6 %. These results suggest that flocked swabs could be a useful and easy to use tool in sampling some organisms from gloved hands in the field as compared to other common sampling devices. Additional work is needed to evaluate multiple organic loads, glove types and additional organisms before a standardized method is developed. These data inform researchers, epidemiologists and infection control personnel as to options for sampling gloved hands in a healthcare setting.

Presenter: Hollis Houston, Centers for Disease Control and Prevention, Atlanta, GA, Email: vvk6 @ cdc. gov

Quality Assurance of Qualitative DNA Detection Assays for Long-term Surveillance Studies of Human Papillomavirus

T. Querec, C. Herbert, E. Kroll, K. Love, P. McKibben, J. Onyekwuluje, Y. Park, S. Patel, J. Pompey, M. Scarbrough and E. Unger, Centers for Disease Control and Prevention, Atlanta, GA

In 2006, the US Food and Drug Administration approved the first human papillomavirus( HPV) vaccine. Since 2005, the Chronic Viral Diseases Branch( CVDB) has tested for HPV genotypes in over 80,000 specimens to measure the impact of vaccination in

US surveillance studies. For reliable monitoring of trends, quality assurance of the assays is vital. CVDB uses multiple processes and controls to assure the performance of qualitative assays for detection of over 30 HPV genotypes. Fidelity of manually read line blot results is ensured by independent double reading and double database entry. Assays include probes for human ß-globin as an endogenous positive control and the frequency of inadequate samples( HPV negative and ß-globin negative) is monitored. Reference samples are run in parallel on current and new lots of kits to bridge lot-to-lot performance. Water blanks are processed with specimens as negative controls for cross-contamination. Positive HPV controls indicate a successful assay run. Ten percent of samples are re-assayed to determine reproducibility and when different types of assays are run on the same samples, assay concordance is determined. Laboratory personnel are trained and evaluated under a quality management system. Since 2007 participation in the WHO HPV LabNet Proficiency Studies has provided an independent assessment of assay performance. Assay results are reviewed quarterly in summary reports before data is submitted to partners. The quality assurance process has led to valuable insights and interventions. In a 2016 comparison between kit lots, the newer lot had weaker signal intensity and lower reproducibility than the current lot in use. Assay procedures were adjusted to maintain performance standards. Approximately 9 months later the vendor reported manufacturing issues. Nonconforming events with water negative controls contaminated with DNA have led to refinement of assay procedures, instrument maintenance and additional training of personnel. Quality assurance can also identify issues that originate outside the laboratory. In the first quarter of 2016, the number of inadequate results for one study tripled from the previous 3 year trend from 6 % to 18 %. The issue was traced to one clinical collection site. The staff were retrained and the inadequate rate returned to baseline. Quality assurance helps to ensure the reliability of HPV genotyping results to measure the impact of vaccination. Future directions include consolidating assay results of different studies into a single relational SQL database and automating summary report creation to track more nuanced data trends and for more frequent monitoring reports.

Presenter: Troy Querec, PhD, Centers for Disease Control and Prevention, Atlanta, GA, Phone: 404.639.2864, Email: hep0 @ cdc. gov

Genomic Sequence Analysis of Common Legionella pneumophila Sequence Types Recovered from Healthcare Facilities

B. Raphael 1, J. Smith 1, L. Cooley 1, S. Roberts 2, E. Brown 1, L. Lie 2, M. Ishaq 2, J. Winchell 1; 1 Centers for Disease Control and Prevention, Atlanta, GA, 2 IHRC, Inc., Atlanta, GA

BEST POSTER 2018

Hospitals and long-term care facilities may contain large, complex water systems which can become colonized with Legionella leading to cases of healthcare-associated Legionnaires’ disease( LD). Individuals in healthcare facilities often have underlying conditions making them more susceptible to LD. The case fatality rate for healthcare-associated LD is approximately 25 %. During outbreak investigations of LD, isolates recovered from clinical specimens and environmental water samples can be analyzed with whole genome MLST( wgMLST) to characterize their genetic relatedness. Detection

Infectious Disease