Lab Matters Fall 2020 - Page 41

Conclusion : Our findings show that HAV can survive and remain infective in the PWID setting for 4 to 10 weeks depending on the type of paraphernalia examined . These findings suggest that sharing of drug paraphernalia by PWIDs can potentially facilitate the transmission of HAV within these populations . Moreover , our results confirm that the plaque assay is currently the only reliable method to determine the infectivity of HAV in vitro .
Presenter : Magdalena Medrzycki , Centers for Disease Control and Prevention , Atlanta , GA , lnu6 @ cdc . gov
CDC Trioplex Real-time RT-PCR Assay : Determining Reagent Stability to Maximize Use , Minimize Waste and Maintain Preparedness
S . Rager , M . White , M . Lawson , M . Rogan , T . Sanders , P . Syribeys and L . Wells , Centers for Disease Control and Prevention , Atlanta , GA
Reagent availability is critical for public health laboratories ’ preparedness to respond to outbreaks . Short reagent shelf-life may limit the availability of these reagents . The CDC Trioplex Real-time RT-PCR Assay ( Trioplex rRT-PCR ) was authorized for Emergency Use by the Food and Drug Administration ( FDA ) March 17 , 2016 in response to the Zika virus outbreak . Shortly thereafter , the CDC ’ s Laboratory Preparedness and Response Branch ( LPRB ) began real-time classical stability studies on the assay reagents to determine the shelf-life and in-use stability . The original shelf-life of the reagents was two years from date of manufacture ( DOM ) at 2-8 ° C for the Trioplex rRT-PCR Primer and Probe Set ( KT0166 ) and one year from DOM at -20 ° C for the Trioplex rRT-PCR Positive Control Set ( KT0167 ). All shelf-life and in-use stability testing was performed in accordance with LPRB ’ s Product Release Testing for the CDC Trioplex rRT-PCR Primer and Probe Set ( KT0166 ), Positive Control Set ( KT0167 ), and Verification Panel work instruction , as described in the approved stability testing study plans . For shelf-life testing , one kit from each of three lots was tested in triplicate at each time point . For in-use stability testing , one kit from one lot was tested in triplicate at each time point . The average Cycle Threshold ( Ct ) value at each time point was calculated and compared to the defined acceptance criteria . With the testing performed to date , the shelf life of KT0166 has been extended from 24 to 30 months , and the shelf-life of KT0167 has been extended from 12 to 24 months . In addition , KT0167 has in-use stability of 24 months when stored at 2-8 ° C or when rehydrated and stored at -20 ° C . Currently , there are thousands of primer and probe vials in inventory that have not been assembled into kits . Continued stability testing will allow us to maximize the expiration date of these reagents . Long-term stability data will support extension of expiration dates of reagents already assembled into kits to maximize use of these valuable reference reagents . At the time of this shelf-life extension , there were 156 positive control kits in inventory that were about to expire , and a production delay with the new lot of positive control . With the approval of the shelf-life extension , the reagents in inventory were able to be reworked by CDC ’ s Division of Scientific Resources ( DSR ) to include the new 2-year expiry dates , thereby , preventing a lapse in availability of the positive control reagent to laboratories . Extension of the shelf-life of Trioplex rRT-PCR reagents allowed CDC to make use of available inventory reducing manufacturing cost and prevent a lapse in reagent availability that would have brought public health laboratories ’ ability to test for Zika virus using this assay to a stop .
Presenter : Stacy Rager , Centers for Disease Control and Prevention , Atlanta , GA , vmk4 @ cdc . gov
Skip the Isolate : Evaluating the Risks Associated with Neisseria gonorrhoeae During DNA Extraction from Clinical Specimens
E . Woodson , G . Woods , E . Nash , J . Reimche , M . Schmerer , J . Cartee , V . Chivukula and B . Raphael , Centers for Disease Control and Prevention , Atlanta , GA
Neisseria gonorrhoeae , the causative agent of gonorrhea , has developed resistance to nearly every class of antibiotic recommended for treatment ; thus , antibiotic resistance data are important for both diagnostics and surveillance . Since most clinical specimens do not have associated isolates , our laboratory is exploring the ability to detect antimicrobial resistance determinants directly from genital and extragenital ( e . g ., pharyngeal , rectal ) clinical specimens . These specimens could introduce laboratory hazards associated with exposure to N . gonorrhoeae and in some case N . menigitidis . The first step to processing these clinical samples involves DNA extraction . Here , we evaluated the potential risks associated with four DNA extraction procedures available in our laboratory ( QIAmp DNA mini kit-both manual and QIAcube automated platform ; iPrep PureLink gDNA Blood kit-automated ; and QIAsymphony DSP kit-automated ). We identified a total of 34 potential hazards , and each was assessed for biological , chemical , or physical risk before and after mitigation ; only hazards identified in more than one procedure were included in the analysis . Before mitigation , 62.5 % of the hazards were associated with moderate to high risk . Based on mitigation measures included in the written procedures , risk was reduced for all hazards ; however , residual risk did remain . Due to the number of potential hazards , we conducted a Pareto analysis to identify hazards with the highest risk , which if properly addressed , should maximize risk reduction with minimal staff effort . This analysis revealed three potential ways to mitigate risk when handling clinical specimens : 1 ) all work must be done in the BSC , 2 ) adjusting the placement of equipment during DNA extraction can prevent / minimize aerosolization of biological hazards , 3 ) specimen transfer should include glove changes and secondary containment . Incorporating these modifications into procedures for extracting DNA from clinical specimens can reduce the risk of laboratory-acquired infections with N . gonorrhoeae and many other pathogens that may be present in these specimens .
The findings and conclusions in this presentation are those of the authors and do not necessarily reflect the official position of the Centers for Disease Control and Prevention .
Presenter : Evonne Woodson , Centers for Disease Control and Prevention , Atlanta , GA , phy2 @ cdc . gov
Ongoing Disseminated Neisseria gonorrhea Outbreak Within Michigan , 2019
H . Blankenship , J . Kent , K . Jones , W . Nettleton , N . Balakrishnan and M . Soehnlen , Michigan Department of Health and Human Services , Lansing , MI
Background : Neisseria gonorrhea is a prominent communicable disease in the United States resulting in 583,000 reported cases annually . Among all reported cases , approximately 0.5-3 % of patients will develop a disseminated gonococcal infection ( DGI ), which occurs when N . gonorrhea enters the bloodstream and disseminates to distal sites within the body . These rare infections can present as bacteremia , septic arthritis , or in severe cases ,
Infectious Disease
Fall 2020 LAB MATTERS 39