Rapid Antigen-Capture Assay To Detect West Nile Virus in Dead Corvids

Lindsay, Robbin; Barker, Ian K.; Nayar, Gopi; Drebot, Michael A.; Calvin, Sharon; Scammell, Cherie; Sachvie, Cheril; Fleur, Tracy Scammell-La Fleur; Dibernardo, Antonia; Andonova, Maya; Artsob, Harvey

doi:10.3201/eid0911.030318

Cited by 39 publications

(45 citation statements)

References 5 publications

(6 reference statements)

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“…In the same way, that the reporting drops off as the season progresses should not affect the results of this study as long as it is not associated with WNV status group. The third situation involves the sensitivity of VecTestH that has been measured at between 78.4% and 92.8%, which is less than ideal (Lindsay et al, 2003;Stone et al, 2004;Stone et al, 2005;Padgett et al, 2006). This weak sensitivity leads to a general underestimation of the number of positive carcasses.…”

Section: Limits Imposed By the Surveillance Systemmentioning

confidence: 99%

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Risk Factors Associated With West Nile Virus Mortality in American Crow Populations in Southern Quebec

Ludwig

Bigras-Poulin

Michel

et al. 2010

Journal of Wildlife Diseases

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ABSTRACT:Soon after the appearance of West Nile virus (WNV) in North America, a number of public health authorities designated the American Crow (Corvus brachyrhynchos) a sentinel for WNV detection. Although preliminary studies have suggested a positive association between American Crow mortality and increased risk of WNV infection in humans, we still know little about dynamic variation in American Crow mortality, both baseline levels and mortality associated with WNV. We hypothesized that the complex social behavior of American Crows, which is shaped by age and seasonal factors, influences both baseline mortality and WNV mortality in American Crow populations. We examined American Crow mortality data from Quebec for the 2005 WNV surveillance year, which lasted from 5 June to 17 September 2005. The variables of interest were age, gender, body condition index, time of year, and land cover. We used a log-linear model to examine baseline mortality. Logistic regression and general linear regression models were constructed to examine variables associated with mortality due to WNV. We found that both age and time of year were key variables in explaining baseline mortality. These two variables were also risk factors for WNV mortality. The probability that a carcass tested positive for WNV increased with the age of the dead bird and as summer progressed. WNV-positive carcasses also had a lower body condition index than WNV-negative carcasses. We believe that the first major wave of American Crow mortality observed in the early summer of 2005 was the result of natural mortality among young American Crows. Because this mortality was not linked to WNV, it appears that American Crow may not be a good species for early detection of WNV activity. Our data also suggest that second-year American Crows play a major role in propagating WNV during their movements to urban land covers during midsummer.

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Section: Limits Imposed By the Surveillance Systemmentioning

confidence: 99%

“…This test has been shown to have relatively good specificity (between 79% and 100%) and sensitivity (between 70.4% and 92.8%) (Lindsay et al, 2003;Stone et al, 2004Stone et al, , 2005Padgett et al, 2006).…”

Section: Sample Collection and Characterizationmentioning

confidence: 99%

Risk Factors Associated With West Nile Virus Mortality in American Crow Populations in Southern Quebec

Ludwig

Bigras-Poulin

Michel

et al. 2010

Journal of Wildlife Diseases

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“…A direct diagnostic test (VecTest®, Medical Analysis Systems, Inc.) was performed on each carcass to determine its status for WNV. This WNV antigen detection test was chosen because of its specificity between 79% and 100% and sensitivity between 70.4% and 92.8% (Lindsay et al 2003;Stone et al 2004;Stone et al 2005;Padgett et al 2006).…”

Section: Data Collectionmentioning

confidence: 99%

Morphological Description of American Crow, <em>Corvus brachyrhynchos</em>, Populations in Southern Quebec

et al. 2009

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The American Crow has always been a much scrutinized bird in North America but, since the emergence of West Nile Virus (WNV) in North America in 1999, public health authorities’ attention to it has been raised another notch. In Québec, like everywhere else in North America, part of the WNV surveillance programme was based on detection of WNV mortality in crow populations. During the summer of the 2005 surveillance season, we followed an age and gender determination protocol, as well as a morphological measurement protocol, on dead crows sent in for WNV status determination, to improve our knowledge of the crow population in Québec. Statistical analysis of the measurements revealed that age and gender were important factors in the morphological characterisation of the American Crow. Bill depth and head-to-bill length appeared as the most important morphological variables for gender prediction through a discriminant function analysis. We also realized that, in adult age groups, our WNV positive carcasses had lower mean weights than carcasses that tested negative for WNV, in adult age groups.Depuis toujours, la corneille d’Amérique est un oiseau très étudié, mais, depuis l’apparition du virus du Nil occidental (VNO) en Amérique du Nord en 1999, l’attention des autorités en santé publique sur cet oiseau a encore augmenté. Au Québec, comme ailleurs en Amérique du Nord, une part importante du programme de surveillance pour la détection du VNO a été basée sur la détection des mortalités liées au VNO dans les populations de corneilles. Pour améliorer notre connaissance de cette espèce au Québec, nous avons mis à profit la récolte des carcasses au cours de l’été 2005 dans le cadre du programme de surveillance en instaurant un protocole de détermination de l’âge, du genre ainsi qu’une prise des mesures morphologiques sur ces mêmes carcasses. L’analyse statistique des résultats a montré qu’à la fois l’âge et le genre étaient des facteurs importants dans la caractérisation morphologique de la corneille d’Amérique. À l’aide de l’analyse discriminante, il est apparu que la profondeur du bec ainsi que la distance tête-bec étaient les mesures les plus importantes pour prédire le genre de l’oiseau. Nos analyses nous ont également permis d’observer que, dans les groupes d’oiseaux adultes, les carcasses positives pour le VNO étaient en moyenne moins lourdes que les carcasses négatives.

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“…The supernatant fraction was clarified by centrifugation at 15,000 ϫ g for 15 min at 4°C before storage at Ϫ70°C. Cell pellets were washed twice with ice-cold phosphate buffered saline (PBS; 140 mM NaCl, 2.7 mM KCl, 0.7 mM KH 2 PO 4 , 6 mM Na 2 HPO 4 , pH 7.5) before lysis in RIPA buffer (50 (80) have shown that this dose of the virus produces an approximately 50% mortality rate in adult hamsters. This strain was originally isolated from the liver of a dead snowy owl at the Bronx Zoo (New York City) in the summer of 1999.…”

Section: Virusmentioning

confidence: 99%

“…The WNV genome encodes a polyprotein that is co-and posttranslationally cleaved into 10 individual gene products: three structural proteins, C, prM, and E, and seven nonstructural proteins, NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5 (47). Antigen capture assays for the surface glycoprotein of the viral particle, the E protein, have been developed for WNV (35) and other flaviviruses (31,41,50,54,58,69,75). For detection of virus, these methods compare favorably with traditional methods of virus isolation in cell culture and suckling mice but are less sensitive than PCR-based methods of detection and do not remain positive after clearance of viremia.…”

mentioning

confidence: 99%

NS1 Protein Secretion during the Acute Phase of West Nile Virus Infection

Macdonald

Tonry

Hall

et al. 2005

J Virol

106

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The West Nile virus (WNV) nonstructural protein NS1 is a protein of unknown function that is found within, associated with, and secreted from infected cells. We systematically investigated the kinetics of NS1 secretion in vitro and in vivo to determine the potential use of this protein as a diagnostic marker and to analyze NS1 secretion in relation to the infection cycle. A sensitive antigen capture enzyme-linked immunosorbent assay (ELISA) for detection of WNV NS1 (polyclonal-ACE) was developed, as well as a capture ELISA for the specific detection of NS1 multimers (4G4-ACE). The 4G4-ACE detected native NS1 antigens at high sensitivity, whereas the polyclonal-ACE had a higher specificity for recombinant forms of the protein. Applying these assays we found that only a small fraction of intracellular NS1 is secreted and that secretion of NS1 in tissue culture is delayed compared to the release of virus particles. In experimentally infected hamsters, NS1 was detected in the serum between days 3 and 8 postinfection, peaking on day 5, the day prior to the onset of clinical disease; immunoglobulin M (IgM) antibodies were detected at low levels on day 5 postinfection. Although real-time PCR gave the earliest indication of infection (day 1), the diagnostic performance of the 4G4-ACE was comparable to that of real-time PCR during the time period when NS1 was secreted. Moreover, the 4G4-ACE was found to be superior in performance to both the IgM and plaque assays during this time period, suggesting that NS1 is a viable early diagnostic marker of WNV infection.

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Rapid Antigen-Capture Assay To Detect West Nile Virus in Dead Corvids

Cited by 39 publications

References 5 publications

Risk Factors Associated With West Nile Virus Mortality in American Crow Populations in Southern Quebec

Risk Factors Associated With West Nile Virus Mortality in American Crow Populations in Southern Quebec

Morphological Description of American Crow, <em>Corvus brachyrhynchos</em>, Populations in Southern Quebec

NS1 Protein Secretion during the Acute Phase of West Nile Virus Infection

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