Lab Matters Fall 2024 | Page 126

APHL 2024 POSTER ABSTRACTS

run separately ) versus multiplex assay performance was tested and compared for each kit . Assay performance across the diversity of Orthohantaviruses was characterized using quantified synthetic viral RNA representative of North and South American New World Orthohantaviruses , as well as select Old World Orthohantaviruses . In addition , a variety of sample types including propagated viral isolates , human clinical samples and rodent surveillance samples were tested to corroborate synthetic RNA experiments and ensure assay relevance in real-world samples . The results suggest that the assay is broadly reactive , thus appropriate for viral detection across a variety of New World Orthohantaviruses . In addition , this work characterizes multiple options for assay design , thus broadening availability of this assay to various public health laboratories .

Presenter : Susan Hepp , susan . hepp @ cdph . ca . gov

Effects of Culture Independent Diagnostic Testing on Enteric Disease Surveillance in Wisconsin , 2018-2023

A . Sanchez 1 , M . Rauch 2 , S . Buechner 2 , A . Bateman 2 , Centers for Disease Control and Prevention 1 , Wisconsin State Laboratory of

Hygiene 2

Background : Enteric pathogens cause ~ 9.4 million illnesses annually in the United States . Campylobacter , Salmonella and Shiga-toxin-producing Escherichia coli ( STEC ) are three of the most identified enteric bacterial infections in Wisconsin . The Wisconsin State Laboratory of Hygiene ( WSLH ) coordinates the Wisconsin Clinical Laboratory Network ( WCLN ), a network of ~ 135 clinical laboratories throughout Wisconsin that submit deidentified summary polymerase chain reaction ( PCR ) data to WSLH weekly . These data are used for pathogen surveillance . WSLH recognized that Wisconsin clinical laboratories had increased use of molecular culture independent diagnostic test ( CIDT ) platforms , such as BioFire ® FilmArray ® ( bioMérieux Inc ., Marcy-l ’ Étoile , France ), for enteric pathogen diagnosis . Culture of CIDT-positive specimens is used to subtype isolates for pathogen surveillance . WSLH requests CIDT-positive specimens and isolates from clinical laboratories . Although some clinical laboratories continue to perform stool culture , WSLH has seen a decline of isolate submissions as clinical laboratory CIDT use increases . To determine effects of a commonly used CIDT , the BioFire ® FilmArray ® multiplex PCR , we analyzed Campylobacter , Salmonella and STEC positivity rates from clinical laboratory data and WSLH culture confirmation results during 2018 – 2023 .

Methods : We analyzed WCLN summary PCR data to calculate and compare positivity rates among different CIDT platforms , including BioFire ® FilmArray ® , for Campylobacter , Salmonella and STEC diagnoses during January 2018 – September 2023 . We also analyzed yearly WSLH culture recovery rates from CIDT-positive specimens initially tested using the BioFire ® FilmArray ® versus other molecular CIDT platforms ; we compared recovery rates between laboratories .

Results : Among specimens tested by a molecular CIDT , BioFire ® FilmArray ® was used on ~ 55 % of specimens tested for Campylobacter , Salmonella and STEC in 2023 . The BioFire ® FilmArray ® had a higher positivity rate for Campylobacter , Salmonella and STEC , compared with other molecular CIDT platforms in each year of the study period . Of CIDT-positive specimens submitted to WSLH during the study period , culture recovery rates for Campylobacter infections were lower for laboratories using BioFire ® FilmArray ® versus other CIDT platforms ( 63 % vs 82 %, respectively ). No differences were observed in culture recovery rates for Salmonella and STEC between BioFire ® FilmArray ® and other platforms .

Conclusion : The BioFire ® FilmArray ® molecular diagnostic platform is currently the most common CIDT platform used by Wisconsin clinical laboratories to diagnose Campylobacter , Salmonella and STEC infections . Higher positivity rates for Campylobacter , Salmonella and STEC might be because of increased sensitivity or false positive results from the BioFire ® FilmArray ® . Decreases in culture recovery rate for Campylobacte- positive specimens detected using BioFire ® FilmArray ® compared with other platforms suggests BioFire ® FilmArray ® may yield false positive Campylobacter results . However , increased positivity rates and similar culture recovery rates for Salmonella and STEC across CIDT-positive specimens , suggests increased sensitivity of BioFire ® FilmArray ® for these pathogens . CIDT-positive specimens , coupled with culture at WSLH , might lead to improved enteric pathogen diagnosis and surveillance .

Presenter : Annie Sanchez , uqp0 @ cdc . gov

Evaluation of Laboratory-based Respiratory Virus Surveillance , Public Health Interoperability Project PHLIP , 2018 – 2023

K . Ciampaglio , A . Winn , R . Dahl , D . Bi , E . Rose , B . Silk , Centers for Disease Control and Prevention

Background : The Public Health Laboratory Interoperability Project ( PHLIP ) was established to facilitate data exchange between public health laboratories ( PHLs ) and CDC using HL7 ® messaging . Weekly PHLIP data are integrated with data from clinical laboratories into the National Respiratory and Enteric Virus Surveillance System ( NREVSS ) to monitor respiratory virus activity . We evaluated respiratory virus data reported via PHLIP before , during and after the COVID-19 pandemic and compared these with data from NREVSS clinical laboratory reports .

Methods : We included respiratory syncytial virus ( RSV ), rhinovirus / enterovirus ( RV / EV ) and SARS-CoV-2 polymerase chain reaction test data reported via PHLIP from July 1 , 2018 until June 30 , 2023 . We calculated the number of reporting sites , average volume of RSV , RV / EV and SARS-CoV-2 tests combined and peaks of percent positivity each surveillance year ( July – June ) and compared the prepandemic ( 2018-2019 ) and pandemic / post-pandemic ( 2020-2023 ) surveillance years . Characteristics between PHLIP ( public health ) and NREVSS ( clinical laboratory ) data were compared . For data reported via PHLIP , we also evaluated the completeness of race and ethnicity variables .

Results : From 2018-2019 to 2022-2023 , the number of PHLs reporting to NREVSS via PHLIP increased 200 % from 10 to 30 , whereas clinical laboratories reporting to NREVSS increased 85 % from 352 to 651 . Average combined test volume each surveillance year was 1,855,888 and 16,564,621 for PHLIP reporting PHLs and NREVSS clinical laboratories , respectively . During the pandemic / post-pandemic surveillance year , the average peak percent positivity was 11.9 % higher in NREVSS compared with PHLIP for RSV , 20.5 % higher in PHLIP compared with NREVSS for RV / EV and was similar between systems for SARS-CoV-2 . In the PHLIP data , completeness of race ( 49.7 %) and ethnicity ( 35.5 %) variables for RSV were lower