scholarly journals H7N7 Avian Influenza Virus Mutation from Low to High Pathogenicity on a Layer Chicken Farm in the UK

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 259
Author(s):  
Alexander M. P. Byrne ◽  
Scott M. Reid ◽  
Amanda H. Seekings ◽  
Alejandro Núñez ◽  
Ana B. Obeso Prieto ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Economic Losses ◽  
Clinical Samples ◽  
Mortality Data ◽  
Molecular Evidence ◽  
High Pathogenicity ◽  
Clinical Protection ◽  
The Uk

Avian influenza virus (AIV) subtypes H5 and H7 are capable of mutating from low to high pathogenicity strains, causing high mortality in poultry with significant economic losses globally. During 2015, two outbreaks of H7N7 low pathogenicity AIV (LPAIV) in Germany, and one each in the United Kingdom (UK) and The Netherlands occurred, as well as single outbreaks of H7N7 high pathogenicity AIV (HPAIV) in Germany and the UK. Both HPAIV outbreaks were linked to precursor H7N7 LPAIV outbreaks on the same or adjacent premises. Herein, we describe the clinical, epidemiological, and virological investigations for the H7N7 UK HPAIV outbreak on a farm with layer chickens in mixed free-range and caged units. H7N7 HPAIV was identified and isolated from clinical samples, as well as H7N7 LPAIV, which could not be isolated. Using serological and molecular evidence, we postulate how the viruses spread throughout the premises, indicating potential points of incursion and possible locations for the mutation event. Serological and mortality data suggested that the LPAIV infection preceded the HPAIV infection and afforded some clinical protection against the HPAIV. These results document the identification of a LPAIV to HPAIV mutation in nature, providing insights into factors that drive its manifestation during outbreaks.

scholarly journals Reverse Transcription Recombinase-aided Amplification Assay for H5 Subtype avian Influenza Virus

2021 ◽  
Author(s):  
Suchun Wang ◽  
Yang Li ◽  
fuyou zhang ◽  
Nan Jiang ◽  
Qingye Zhuang ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Reverse Transcription ◽  
Clinical Sample ◽  
Economic Losses ◽  
Clinical Samples ◽  
Analytical Sensitivity ◽  
Single Temperature ◽  
H5 Subtype

Abstract Background: The H5 subtype avian influenza virus (AIV) has caused huge economic losses to the poultry industry and is a threat to human health. A rapid and simple test is needed to confirm infection in suspected cases during disease outbreaks. Methods: In this study, we developed a reverse transcription recombinase-aided amplification (RT-RAA) assay for the detection of H5 subtype AIV. Assays were performed at a single temperature (39°C), and the results were obtained within 20 min. Results: The assay showed no cross-detection with Newcastle disease virus or infectious bronchitis virus. The analytical sensitivity was 103 RNA copies/μL at a 95% confidence interval according to probit regression analysis, with 100% specificity. Compared with published reverse transcription quantitative real-time polymerase chain reaction assays, the κ value of the RT-RAA assay in 420 avian clinical samples was 0.983 (p < 0.001). The sensitivity for avian clinical sample detection was 97.26% (95% CI, 89.56–99.52%), and the specificity was 100% (95% CI, 98.64–100%). Conclusions: These results indicated that our RT-RAA assay may be a valuable tool for detecting H5 subtype AIV.

scholarly journals Reverse-transcription recombinase-aided amplification assay for H5 subtype avian influenza virus

2020 ◽  
Author(s):  
Suchun Wang ◽  
Yang Li ◽  
Nan Jiang ◽  
Fuyou Zhang ◽  
Qingye Zhuang ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Reverse Transcription ◽  
Economic Losses ◽  
Clinical Samples ◽  
Analytical Sensitivity ◽  
Single Temperature ◽  
Amplification Assay ◽  
H5 Subtype

AbstractThe H5 subtype Avian Influenza Virus has caused huge economic losses to the poultry industry and is a threat to human health. A rapid and simple test is needed to confirm infection in suspected cases during disease outbreaks. In this study, we developed a reverse-transcription recombinase-aided amplification assay for the detection of H5 subtype avian influenza virus. Assays were performed at a single temperature (39°C), and the results were obtained within 20 min. The assay showed no cross-detection with Newcastle disease virus or infectious bronchitis virus. The analytical sensitivity was 103 RNA copies per reaction at a 95% confidence interval according to probit regression analysis, with 100% specificity. Compared with published reverse-transcription quantitative real-time polymerase chain reaction assays, the κ value of the reverse transcription recombinase-aided amplification assay in 365 avian clinical samples was 0.970 (p < 0.001). The sensitivity for avian clinical sample detection was 94.44% (95%CI, 70.63% - 99.71%), and the specificity was 100% (95%CI, 98.64% - 100%). These results indicated that our reverse-transcription recombinase-aided amplification assay may be a valuable tool for detecting H5 subtype avian influenza virus.

scholarly journals Prevalence and Diversity of Avian Influenza Virus Hemagglutinin Sero-Subtypes in Poultry and Wild Birds in Bangladesh

2020 ◽  
Vol 7 (2) ◽  
pp. 73 ◽  
Author(s):  
Mohammad M. Hassan ◽  
Mohamed E. El Zowalaty ◽  
Ariful Islam ◽  
Shahneaz A. Khan ◽  
Md. K. Rahman ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Migratory Birds ◽  
Bird Species ◽  
Wild Birds ◽  
Economic Losses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Influenza Virus Hemagglutinin

Highly pathogenic avian influenza H5 viruses have pandemic potential, cause significant economic losses and are of veterinary and public health concerns. This study aimed to investigate the distribution and diversity of hemagglutinin (HA) subtypes of avian influenza virus (AIV) in poultry and wild birds in Bangladesh. We conducted an avian influenza sero-surveillance in wild and domestic birds in wetlands of Chattogram and Sylhet in the winter seasons 2012–2014. We tested serum samples using a competitive enzyme-linked immunosorbent assay (c-ELISA), and randomly selected positive serum samples (170 of 942) were tested using hemagglutination inhibition (HI) to detect antibodies against the 16 different HA sero-subtypes. All AIV sero–subtypes except H7, H11, H14 and H15 were identified in the present study, with H5 and H9 dominating over other subtypes, regardless of the bird species. The diversity of HA sero-subtypes within groups ranged from 3 (in household chickens) to 10 (in migratory birds). The prevalence of the H5 sero-subtype was 76.3% (29/38) in nomadic ducks, 71.4% (5/7) in household chicken, 66.7% (24/36) in resident wild birds, 65.9% (27/41) in migratory birds and 61.7% (29/47) in household ducks. Moreover, the H9 sero-subtype was common in migratory birds (56%; 23/41), followed by 38.3% (18/47) in household ducks, 36.8% (14/38) in nomadic ducks, 30.6% (11/66) in resident wild birds and 28.5% (2/7) in household chickens. H1, H4 and H6 sero-subtypes were the most common sero-subtypes (80%; 8/10, 70%; 7/10 and 70%; 7/10, respectively) in migratory birds in 2012, H9 in resident wild birds (83.3%; 5/6) and H2 in nomadic ducks (73.9%; 17/23) in 2013, and the H5 sero-subtype in all types of birds (50% to 100%) in 2014. The present study demonstrates that a high diversity of HA subtypes circulated in diverse bird species in Bangladesh, and this broad range of AIV hosts may increase the probability of AIVs’ reassortment and may enhance the emergence of novel AIV strains. A continued surveillance for AIV at targeted domestic–wild bird interfaces is recommended to understand the ecology and evolution of AIVs.

scholarly journals High-Pathogenicity Avian Influenza Virus in the Reproductive Tract of Chickens

2013 ◽  
Vol 50 (6) ◽  
pp. 956-960 ◽  
Author(s):  
M.Sá e Silva ◽  
D. R. Rissi ◽  
M. Pantin-Jackwood ◽  
D. E. Swayne
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Reproductive Tract ◽  
High Pathogenicity

Detection of H5N1 High-Pathogenicity Avian Influenza Virus in Meat and Tracheal Samples from Experimentally Infected Chickens

2008 ◽  
Vol 52 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Amaresh Das ◽  
Erica Spackman ◽  
Colleen Thomas ◽  
David E. Swayne ◽  
David L. Suarez
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
High Pathogenicity
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