APHL 2021 Poster Abstracts
COVID-19 using ddPCR . Future work could include concentration of collected aerosol samples for better sensitivity , especially when combined with contemporaneous wastewater collection and concentration , for a broader and sensitive composite evaluation of local conditions with regard not only to COVID but also to other viral and bacterial pathogens .
Presenter : David Alburty , InnovaPrep LLC , dalburty @ innovaprep . com
The Public Health and Financial Implications of State Hygienic Laboratory Serology Testing in Relation to Convalescent Plasma Donations and Illness Prevention
D . Shostrom , M . Pentella and W . Aldous , State Hygienic Laboratory at the University of Iowa , Coralville , IA
Since the emergence of COVID-19 in Iowa , the State Hygienic Laboratory at the University of Iowa ’ s ( SHL ) serology testing has played a key role in detecting COVID-19 antibodies in previously infected individuals and identifying potential donors for convalescent plasma . Given the potential benefits of using convalescent plasma therapy ( CPT ) in severe cases of COVID-19 , we sought to quantify the health and financial impact of SHL ’ s serology testing from April 2020 – February 2021 . We determined that SHL performed 44,052 serology tests for two blood donor centers in Iowa , identifying 9,189 high titer specimens . Using data provided by plasma donation centers , we calculated the number of plasma units produced from donors identified by SHL serology testing to be approximately 18,000 units . To explore the potential benefits of the plasma produced , we created a model based on published estimates of health outcomes in severe cases of COVID-19 where CPT was provided , and the assumption that total units of plasma produced represented a maximum of 18,000 individual CPT treatments . The laboratory costs associated with performing serology testing by SHL during the study period , along with the potential cost savings from improved prognoses among hypothetical CPT recipients were combined to generate a net benefit value . Lastly , a sensitivity analysis was performed to determine the net benefits under varying degrees of CPT effectiveness and costs of treatment .
Presenter : Derrick Shostrom , State Hygienic Laboratory at the University of Iowa , derrick-shostrom @ uiowa . edu
Impact of Public Health Laboratory COVID-19 PCR Testing and State Health Department Contact Tracing on COVID-19 : A Cost-Effectiveness Analysis
D . Shostrom , M . Pentella and W . Aldous , State Hygienic Laboratory at the University of Iowa , Coralville , IA
The cost-effectiveness of testing and contact tracing and their public health implications for the COVID-19 pandemic response is relatively unknown . Using data collected from the State Hygienic Laboratory at the University of Iowa ( SHL ) and Iowa Department of Public Health ( IDPH ), published cost estimates , and guidance from the Health Economics and Modeling Unit from CDC , we performed a cost-effectiveness analysis of SHL ’ s COVID-19 PCR testing and subsequent contact tracing efforts from March-December 2020 . Using an asymptomatic rate of 35 %, we estimated that 16,282 of the 46,519 positive PCR tests identified by SHL during the study period are assumed to be asymptomatic cases . Using a modelling equation , we calculated the number of new infections that would result if positive asymptomatic cases were not identified or contacted by contact tracers . Applying published estimates for the average cost of symptomatic infections and infections requiring hospitalizations , we calculated the overall medical costs averted from these interventions to be estimated at $ 118.1 - $ 236.3 million . Upon collection of all costs associated with testing and contact tracing , we will determine the cost-effectiveness and impact of these mitigation strategies . Finally , using sensitivity analyses , we explore how changes in testing and contact tracing turnaround time , basic reproductive number , and testing volume impact overall costeffectiveness .
Presenter : Derrick Shostrom , State Hygienic Laboratory at the University of Iowa , derrick-shostrom @ uiowa . edu
Routine PCR Screenings at a Dallas County Hospital Identifies the First Case of SARS-CoV-2 Reinfection in Texas
C . Aroh 1 , S . Marcellus 2 , G . Perez 3 , J . Williams 3 , C . Columbus 3 , R . Benavides 3 , M . Askar 3 , C . Wang 2 , R . Lee 2 , G . Kubin 2 , J . Stringer 1 , E . Bannister 1 ; 1 Dallas County Health and Human Services , Dallas , TX , 2 Texas Department of State Health Services , Austin , TX , 3 Baylor University Medical Center , Waco , TX
Asymptomatic transmissions of SARS-CoV-2 contribute an estimated 24 % of all COVID-19 spread . The progression of SARS-CoV-2 infection and the longevity of natural immunity in asymptomatic but infectious persons is unknown . Re-infection cases identified by routine pre-operative or pre-admission PCR screens of hospitalized patients can provide important insights to both questions . Here we describe a case of a 36-year-old male resident of Dallas County , TX who on 7 / 6 / 20 presented to a local emergency department with necrotizing fasciitis requiring multiple surgical debridements and broad spectrum antibiotic treatment . At presentation , routine preoperative PCR screens identified the patient to be asymptomatically infected with SARS-CoV-2 and highly infectious ( average PCR cycle threshold , or Ct , of 12 on ThermoFisher TaqPath assay ). The patient then had multiple ( 3 ) negative PCR tests but later developed low titer PCR positive results , also identified by routine screens , at 76 days ( average Ct of 33 ) and 90 days ( average Ct of 34 ) after the first positive nasopharyngeal ( NP ) specimen . The patient had two SARS-CoV-2 nucleocapsid IgG antibody tests done with a negative result at the patient ’ s initial presentation and a positive result 78 days later . Suspicion of re-infection triggered the retrieval of the day zero and day 90 positive NP samples , the other being lost , for submission for next generation sequencing ( NGS ) to the Texas State Public Health Laboratory . Phylogenetic analysis of the 7 / 6 / 20 and 10 / 4 / 20 samples indicated that the infecting viruses belonged to distinct SARS-CoV-2 clades , 20A and 20C , with 9 and 11 amino acid changing mutations , respectively . Notably , both viruses shared the D614G coronavirus spike protein mutations present in all three clades of SARS-CoV-2 variants of concern ; but in the day 90 sample alone it was coupled to the neutral L54F mutation , one of three mutations commonly associated with D614G . Altogether seventeen single nucleotide mutations separated the two specimens , more than would be expected under the alternative hypothesis of lingering viral shedding , thus strongly indicating this patient as the first laboratory-confirmed re-infection diagnosis in Texas . Our case study implies that SARS-CoV-2 re-infection of naturally or vaccine immunized person may be more common than
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LAB MATTERS Summer 2021 |
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