Beard, C. W. Demonstration of type-specific influenza antibody in mammalian and avian sera by immunodiffusion. Bull. WHO

Bulletin of the World Health Organisation (Impact Factor: 5.09). 02/1970; 42(5):779-85.
Source: PubMed


The detection of antibody against the ribonucleoprotein antigen of influenza virus is useful because its type-specificity allows the use of serological surveys to detect evidence of recent infections. Antigenic differences between strains limit the usefulness of the techniques, such as the haemagglutination-inhibition test, that detect antibody against surface antigens.This paper describes an agar-gel precipitation (AGP) test that will detect type-specific antibody in avian or mammalian sera. Convalescent levels of antibody against either type A or B influenza virus were demonstrated in human sera. Positive but inconsistent results were obtained with swine sera. The antigens used in the AGP test are non-infectious and stable. The test is easy and economical to perform. Its sensitivity compares favourably with that of the complement-fixation test using human and equine sera.While not a replacement for any of the serological tests at present in current use, the AGP test should prove useful in a variety of diagnostic and research situations.

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    • "Serum samples collected pre- and post-inoculation were tested for anti-influenza virus A antibodies via the FlockCheck Avian Influenza MultiS-Screen Antibody Test Kit (IDEXX Laboratories, Inc., Westbrook, ME) and Agar Gel Immunodiffusion (AGID) [27], [28]. "
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    ABSTRACT: Background Cottontails (Sylvilagus spp.) are common mammals throughout much of the U.S. and are often found in peridomestic settings, potentially interacting with livestock and poultry operations. If these animals are susceptible to avian influenza virus (AIV) infections and shed the virus in sufficient quantities they may pose a risk for movement of avian influenza viruses between wildlife and domestic animals in certain situations. Methodology/Principal Findings To assess the viral shedding potential of AIV in cottontails, we nasally inoculated fourteen cottontails with a low pathogenic AIV (H4N6). All inoculated cottontails shed relatively large quantities of viral RNA both nasally (≤106.94 PCR EID50 equivalents/mL) and orally (≤105.09 PCR EID50 equivalents/mL). However, oral shedding tended to decline more quickly than did nasal shedding. No animals showed any obvious signs of disease throughout the study. Evidence of a serological response was found in all infected rabbits at 22 days post infection in convalescent sera. Conclusions/Significance To our knowledge, cottontails have not been previously assessed for AIV shedding. However, it was obvious that they shed AIV RNA extensively via the nasal and oral routes. This is significant, as cottontails are widely distributed throughout the U.S. and elsewhere. These mammals are often found in highly peridomestic situations, such as farms, parks, and suburban neighborhoods, often becoming habituated to human activities. Thus, if infected these mammals could easily transport AIVs short distances.
    PLoS ONE 08/2014; 9(8):e102513. DOI:10.1371/journal.pone.0102513 · 3.23 Impact Factor
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    • "Neuraminidase inhibition determines the antibody subtypes present in the sera that are directed against the neuraminidase protein on the surface of the virus. These procedures are described by Beard (1970), and all procedures were performed at the Center for Veterinary Biologics and NVSL using their protocols. "
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    ABSTRACT: Swine play an important role in the disease ecology of influenza. Having cellular receptors in common with birds and humans, swine provide opportunities for mixed infections and potential for genetic reassortment between avian, human, and porcine influenza. Feral swine populations are rapidly expanding in both numbers and range and are increasingly coming into contact with waterfowl, humans, and agricultural operations. In this study, over 875 feral swine were sampled from six states across the United States for serologic evidence of exposure to influenza. In Oklahoma, Florida, and Missouri, USA, no seropositive feral swine were detected. Seropositive swine were detected in California, Mississippi, and Texas, USA. Antibody prevalences in these states were 1% in Mississippi, 5% in California, and 14.4% in Texas. All seropositive swine were exposed to H3N2 subtype, the predominant subtype currently circulating in domestic swine. The only exceptions were in San Saba County, Texas, where of the 15 seropositive samples, four were positive for H1N1 and seven for both H1N1 and H3N2. In Texas, there was large geographical and temporal variation in antibody prevalence and no obvious connection to domestic swine operations. No evidence of exposure to avian influenza in feral swine was uncovered. From these results it is apparent that influenza in feral swine poses a risk primarily to swine production operations. However, because feral swine share habitat with waterfowl, prey on and scavenge dead and dying birds, are highly mobile, and are increasingly coming into contact with humans, the potential for these animals to become infected with avian or human influenza in addition to swine influenza is a distinct possibility.
    Journal of wildlife diseases 05/2008; 44(2):362-8. DOI:10.7589/0090-3558-44.2.362 · 1.36 Impact Factor
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    • "Hemagglutination inhibition assay was used to assess the seroprevalence of IBV viral antigens in the serum samples as previously described (Beard, 1970). Briefly, the serum samples were added in 96-well round bottom microtiter plates. "
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    ABSTRACT: This study was conducted to investigate the incidence of infectious bronchitis virus (IBV) in commercial broiler and layer flocks in Pakistan. Serum samples from 16 layers and 9 broiler flocks were screened against M-41, D-274, D-1466, and 4-91 strain antigens using hemagglutination inhibition assay. Overall, 88% of the flocks were seropositive for M-41 antibodies, whereas 40, 52, and 8% of the flocks were positive for D-274, D-1466, and 4-91 IBV strains, respectively. The M-41 antigen was also detected in lungs and tracheal tissues of the clinically positive infectious bronchitis cases. Phospholipase C treatment of the lung and tracheal tissue homogenates from IBV-positive chickens increased the detection limit for M-41 strain from 1.3% positive samples in simple hemagglutination assay to 30.6% positivity when the same samples were treated with phospholipase C. Similarly, reverse transcription-PCR was a much better M-41 detection tool as compared with the classical agar gel precipitation assay utilized to screen tissue homogenates from IBV-positive chickens. In conclusion, this survey clearly demonstrates that several strains of IBV are prevalent in poultry flocks in Pakistan. By utilizing such diagnostic techniques it is possible to conduct a detailed epidemiological study to determine the full economic impact of this disease.
    Poultry Science 08/2007; 86(7):1329-35. DOI:10.1093/ps/86.7.1329 · 1.67 Impact Factor
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