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.,
[email protected]
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
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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,
[email protected]
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,
[email protected]
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
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