Lab Matters Fall 2024 | Page 57

APHL 2024 POSTER ABSTRACTS distribution of BabyBIG ® , a human antitoxin for life-saving efforts . Laboratory testing is required in the algorithm for the distribution of the antitoxin . Pennsylvania Department of Health Bureau of Laboratories ( PADOH BOL ) performs Laboratory Response Network for Biological Threats ( LRN-B ) bacteriology mouse bioassay protocol for the detection of botulinum neurotoxin . This method tests for neurotoxins directly in serum , stool extracts , food and other environmental extracts . Currently , this is the LRN-B ’ s only acceptable method for the detection and confirmatory identification of botulinum neurotoxin . PADOH BOL tested 445 specimens from 2013-2023 with an average of fifty specimens annually . The positivity rate is over 50 %. Based on the information contributed to CDC surveillance data , Pennsylvania has the second highest rate of infant botulinum , second to California . Analysis will be broken down by state , county , age and trends .

Presenter : Lisa Dettinger , ldettinger @ pa . gov

Evaluating the Suitability of the Seegene Novaplex PCR System for Respiratory Pathogen Surveillance in Minnesota

E . Yarosz 1 , S . Bistodeau 2 , A . Panek 2 , M . Bowman 2 , S . Cunningham 2 , A . Strain 2 , Centers for Dis-ease Control and Prevention 1 , Minnesota Department of Health 2

Background : Respiratory infections cause significant morbidity and mortality in the United States each year . The Minnesota Department of Health Public Health Laboratory ( MDH-PHL ) uses the Luminex NxTAG Respiratory Pathogen Panel ( RPP ) to screen for 19 viruses and three bacterial species in respiratory samples collected throughout Minnesota . However , identifying common respiratory bacterial pathogens like S . pneumoniae , H . influenzae and B . pertussis and differentiating between rhinovirus and enterovirus ( RV / EV ) infection requires additional testing . Furthermore , the Luminex NxTAG RPP is a labor-intensive process requiring hands-on work from a trained technician . The Seegene Novaplex PCR system is a fully automated testing platform that detects 20 individual viruses and can differentiate between RV / EV . This platform can also identify seven bacterial species , reducing the amount of singletarget testing needed to detect bacterial pathogens . Because of these potential benefits , we sought to determine the suitability of the Seegene Novaplex PCR system for performing respiratory surveillance at MDH-PHL .

Methods : We used the Seegene Novaplex PCR system to test 543 patient specimens previously analyzed by the Luminex NxTAG RPP during March 2015 – September 2023 . Acceptable specimen types included upper and lower respiratory swabs and washes as well as sputum . Data from both platforms were compared to determine percent agreement . The ability of the Seegene Novaplex system to correctly distinguish between RV / EV and detect SARS-CoV-2 was determined by comparing the results to our validated RV / EV and FluSC2 PCR assays , respectively . Data from bacteri-al PCR panels were taken from the MDH-PHL laboratory information system to assess the Seegene Novaplex system ’ s ability to identify H . influenzae , S . pneumoniae , B . pertussis and B . parapertussis .

Results : Preliminary analysis showed 79.2 % agreement between the Seegene Novaplex PCR system and the Luminex NxTAG RPP . Moreover , the Seegene Novaplex PCR system increased detection of B . pertussis and B . parapertussis , both of which are not included in the Luminex NxTAG RPP . We also found that the Seegene

Novaplex system appears to accurately discriminate between RV / EV , as preliminary data showed 81.5 % agreement between the Seegene Novaplex PCR system and our RV / EV PCR assay . Although further analysis is needed , our data showed 70 % agreement between the Seegene Novaplex PCR system and our validated FluSC2 assay in de-tecting the presence of SARS-CoV-2 . Lastly , we found that the results from the Seegene Novaplex system and our current bacterial PCR panel agreed 49.3 % of the time for H . influenzae and S . pneumoniae , with the Seegene Novaplex system typically detecting both bacteria more often .

Conclusions : Although overall detection of viral pathogens was not enhanced , we found that the Seegene Novaplex PCR system reliably distinguishes between RV / EV , potentially allowing MDH- PHL to discontinue use of a separate RV / EV PCR . Identification of H . influenzae and S . pneumoniae was also higher when using the Seegene Novaplex system , but increased false positivity rates and sensing of commensal bacteria cannot yet be ruled out . Lastly , the Seegene Novaplex PCR system increased detection of Bordetella species and might improve surveillance of these historically underrepresented bacterial pathogens in Minnesota .

Presenter : Emily Yarosz , CDC , Email : tqf7 @ cdc . gov

Expansion of Transit Time on the Detection of HCV Using Aptima 2 HCV Quant DX Assay

S . Sweets , A . Lucas , B . Pope , J . Yeadon , L . Fulford , C . Evans , L . Liu , Indiana Department of Health

Background : The Indiana Department of Health Laboratory ( IDOHL ) currently performs testing for HCV antibodies using the Abbott Alinity i platform and the Hologic Panther Fusion instrument with the Hologic ® Aptima ® HCV Quant Dx Assay for HCV NAAT testing . IDOHL receives an aver-age of 11,400 specimens annually for HCV screening . Of those , approximately 21 % or 2,400 specimens screen as reactive by the Alinity anti-HCV assay . Of the 2,400 reactive specimens we test annually , 50.5 % or 1,212 meet the manufacturers guidelines by being received at IDOHL within 24 hours of specimen collection . By extending the transit time for HCV NAAT testing to three days at room temperature , IDOHL would be able to test an additional 893 specimens annually allowing for IDOHL to test 88 % of reactive specimens submitted .

Method : IDOHL designed a transit study using pooled specimens organized into four predefined categories ; negative , < 10 IU / mL , 10-25 IU / mL and 25-100M IU / mL . Up to ten original or contrived specimens for each reportable range were made into aliquots , the 10-25 IU / mL category consisted solely of specimens made from Hologic controls and Hologic diluent . All specimens were kept at room temperature and tested on days 1-4 and seven using the Hologic ® Aptima ® HCV Quant Dx Assay . The results were then analyzed to determine extension of transit time .

Results : Up to day four , the results of all specimens in negative , < 10 IU / mL and 25-100M IU / mL categories remained in the targeted ranges . However , the results of specimens in the 10-25 IU / mL category are only able to stay in the targeted range for one day at room temperature , as per the manufacturers package insert .

Conclusion : The current results of this study are promising for the three out of four categories that we have assessed . The results of the 10-25 IU / mL category may have been impacted by the diluent