Lab Matters Summer 2019 - Page 75

APHL 2019 POSTER ABSTRACTS Methods: Two antigens, the POWV glycoprotein E (gE) and the non- structural protein 1 (NS1), were separately coated on microplates. Both antigens were compared with respect to sensitivity and specificity for the detection of anti-POWV IgM and IgG using the following panels. Sensitivity panel: 7 samples from patients with acute POWV infection, characterized as positive for anti-POWV IgM (confirmed by plaque reduction neutralization assay) at the Wadsworth Center NYSDOH, USA. Specificity panel: 171 samples of healthy individuals (49 blood donors, 73 pregnant women, 49 children). Cross-reactivity panel: Patients positive for antibodies against dengue virus (DENV, 51 IgM, 58 IgG), West Nile virus (WNV, 47 IgM, 38 IgG) or Zika virus (ZIKV, 8 IgM, 37 IgG) using ELISA. Results: In the sensitivity panel, IgM was detected in 100% (7/7) of samples using POWV gE and in 85.7% (6/7) using POWV NS1 as antigen. IgG was detected in 85.7% (6/7) of samples using gE and in 42.9% (3/7) using NS1. Specificity was higher using NS1 compared to gE (IgM: 97.1% (gE) vs. 97.7% (NS1); IgG: 79.5% (gE) vs. 98.2% (NS1)). Cross-reactivity was comparable (DENV, ZIKV) or lower (WNV) when using NS1 instead of gE for the detection of IgM and considerably reduced for the detection of IgG. Discussion: The gE-based ELISA revealed highest sensitivity for anti- POWV IgM to detect acute POWV infections. Specificity with respect to healthy individuals and other flavivirus infections was higher when using NS1 instead of gE for IgM detection and to an even greater extent for IgG detection. Comparison between the highly conserved gE and the more species-specific NS1 protein suggests a strategy based on two ELISAs: Sensitive detection of anti-POWV IgM with the gE-based ELISA and specific detection of anti-POWV IgG with the NS1-based ELISA, e. g. in patient follow-up samples or in seroprevalence studies. Presenter: Oliver Sendscheid, EUROIMMUN US, Inc., oliver.sendscheid@euroimmun.us Chicken and Egg: A Catch 22 Paradox for Surveillance and Control of Avian Influenza B. Backstedt, J. Michelotti, L. Gardiner, J. Lucas, G. Olinger and K. Yeh, MRIGlobal Biosurveillance is the process of detecting syndromic, molecular and serological evidence of relevant disease pathogens in animals, humans and the environment. It can provide the epidemiological knowledge to prevent disease spread to humans or other animals and potentially protect against bioterrorism events. Outbreaks of highly pathogenic avian influenza (HPAI) and other high consequence pathogens in bird and livestock populations generate public health responses that often result in significant culling of domesticated animals and wild reservoirs. A robust One Health biosurveillance approach for HPAI in wild and domestic fowl, particularly chickens, ducks, and geese, aims to reduce the negative impact of outbreak events leading to improved global health security. Theoretically, earlier disease control response can be implemented if active biosurveillance on all farms is in place and the HPAI is detected earlier based on its activity in neighboring regions. Additionally, limiting the spread and overall prevalence of HPAI among wild and domestic fowl could decrease the likelihood of human exposure. We performed a systematic review of published data on HPAI outbreaks over the past five years including the PublicHealthLabs @APHL APHL.org efficacy of containment by stamping out the affected bird reservoirs and economic impacts. The effectiveness of culling infected flocks varied widely by outbreak, likely due to additional factors such as wild bird movement and prevalence of domestic backyard flocks. The World Organization for Animal Health (OIE) maintains standards and recommendations for veterinary diagnostic reference labs. However, due to the costs, resources, and technical skills required for diagnostic testing, most HPAI testing occurs only after the discovery of sick or dead birds, allowing a strong possibility for further spread and potential human exposure before confirmation of the outbreak. From our capacity building experience especially in low and middle income countries, there remains a continuing need for simple, low cost, active biosurveillance of HPAI and continued personnel biosafety training to prevent human exposure. Presenter: Brian Backstedt, MRIGlobal, Kansas City, MO, bbackstedt@mriglobal.org Diagnostic Drug Susceptibility Testing Platform Comparison for the NIAID Mycobacterium tuberculosis Quality Assurance Program Isolate Repository E. Tacheny 1 , R. Howard 1 , N. Parrish 2 , D. Armstrong 3 , J. Coffin 1 ; 1 MRIGlobal, 2 Johns Hopkins University, 3 Johns Hopkins Hospital The World Health Organization (WHO) listed tuberculosis as one of the top ten causes of death worldwide in 2016 and the leading cause of death among people with HIV. Additionally, the WHO estimates that in 2016, 490,000 people developed multidrug- resistant tuberculosis (MDR-TB). These patients have a form of tuberculosis resistant to both first-line drugs, rifampicin and isoniazid. This necessitates treatment using second-line anti- tuberculosis drugs such as fluoroquinolones or injectable drugs like kanamycin. However, only an estimated 1 in 4 MDR-TB patients receive the correct antibiotic regimen. Further research is needed to better detect and diagnose MDR-TB drug susceptibility, in order to provide guidance for healthcare professionals to prescribe the right treatment regimen for a patient. Here, our team presents a combined drug susceptibility profile of clinical Mycobacterium tuberculosis (Mtb) isolates for the National Institutes of Health (NIH-DAIDS) Mycobacterium tuberculosis Quality Assessment Program (TBQA), contract number HHSN272201700001C. The data presented here compares established methods of antimicrobial resistance (AMR) detection including conventional culture-based methods and newer, culture-independent molecular diagnostics. Our team presents each method side-by-side for results comparison in an effort to provide guidance on the performance of each method for the determination of drug susceptibility. Presenter: Ryan Howard, MRIGlobal, Kansas City, MO, rhoward@mriglobal.org Assessment of Laboratory Procedures and Sample Handling for Optimal Detection of Mycobacterium tuberculosis in Gastric Fluid J. Coffin, T. Dickerson, R. Howard and E. Tacheny, MRIGlobal Worldwide, tuberculosis (TB) is one of the top 10 causes of death and the leading cause from a single infectious agent. As per the 2018 WHO Global Tuberculosis report, in 2017, an estimated 1 million children became ill with TB and 230,000 children died of Summer 2019 LAB MATTERS 73