Phylogenetic Analysis of H7 Avian Influenza Viruses Isolated from the Live Bird Markets of the Northeast United States

ABSTRACT The presence of low-pathogenic H7 avian influenza virus (AIV), which is associated with live-bird markets (LBM) in the Northeast United States, was first detected in 1994 and, despite efforts to eradicate the virus, surveillance of these markets has resulted in numerous isolations of H7 AIVs from several states from 1994 through 1998. The hemagglutinin, nonstructural, and matrix genes from representative H7 isolates from the LBM and elsewhere were sequenced, and the sequences were compared phylogenetically. The hemagglutinin gene of most LBM isolates examined appeared to have been the result of a single introduction of the hemagglutinin gene. Evidence for evolutionary changes were observed with three definable steps. The first isolate from 1994 had the amino acid threonine at the −2 position of the hemagglutinin cleavage site, which is the most commonly observed amino acid at this site for North American H7 AIVs. In January 1995 a new genotype with a proline at the −2 position was detected, and this genotype eventually became the predominant virus isolate. A third viral genotype, detected in November 1996, had an eight-amino-acid deletion within the putative receptor binding site. This viral genotype appeared to be the predominant isolate, although isolates with proline at the −2 position without the deletion were still observed in viruses from the last sampling date. Evidence for reassortment of multiple viral genes was evident. The combination of possible adaptive evolution of the virus and reassortment with different influenza virus genes makes it difficult to determine the risk of pathogenesis of this group of H7 AIVs.

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Molecular and Biological Characteristics of H5 and H7 Avian Influenza Viruses in Live-Bird Markets of the Northeastern United States, 1994–2001

Avian Diseases ◽

10.1637/0005-2086-47.s3.898 ◽

2003 ◽

Vol 47 (s3) ◽

pp. 898-904 ◽

Cited By ~ 28

Author(s):

D. A. Senne ◽

D. L. Suarez ◽

J. C. Pedersen ◽

B. Panigrahy

Keyword(s):

United States ◽

Avian Influenza ◽

Influenza Viruses ◽

Biological Characteristics ◽

Northeastern United States ◽

Avian Influenza Viruses ◽

Live Bird Markets ◽

Live Bird

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The Presence of Poultry Influenza Strains in Two Live Bird Markets near the East-West Boundary of Vietnam

BioMed Research International ◽

10.1155/2020/1487651 ◽

2020 ◽

Vol 2020 ◽

pp. 1-5

Author(s):

Quynh Anh Tran ◽

Huong Le Thi ◽

Xuan Thi Thanh Le ◽

Thanh To Long

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Influenza Viruses ◽

Asian Countries ◽

Live Bird Markets ◽

Pathogenic Avian Influenza Virus ◽

Chicken Sample ◽

East West ◽

Live Bird

The spread of avian influenza virus among Asian countries is becoming a concern after influenza epidemics in recent years. This study is aimed at identifying the subtypes of avian influenza viruses collected from healthy chickens and ducks at two live bird markets in a border province of Vietnam and the Lao People Democratic Republic. Cloacal and tracheal swab samples from 100 chickens and 101 ducks were collected in May 2017. All samples were screened to detect avian influenza virus by real-time reverse transcriptase PCR. Samples that are avian influenza virus-positive were isolated in embryonated chicken eggs, and the subtypes were identified by RT-PCR with the specific primers. The samples positive for influenza virus H5 were sequenced to identify HA and NA genes. The prevalence of avian influenza virus (AIV) among chicken and duck samples was 27.5% (55/200) and 24.8% (50/202), respectively. AIV subtypes identified among 17 samples positive with the hemagglutination test include H3N6, H6N6, and H9N2. Of these 17 samples, 7 duck samples were found to be H6N6, 4 duck samples were infected with both subtypes of H3N6 and H6N6, and two chicken samples were recorded as H9N2. A positive chicken sample with A/H5 contains 99% similarity nucleotide with H5N6 reference strain. Results suggested that while the presence of low pathogenic avian influenza virus is predominant, potential risks of the appearance of high pathogen avian influenza virus in the east-west boundary in Vietnam should be concerned and studied further. Furthermore, prevention activities are needed to reduce such biosecurity threats in Vietnam and other Asian countries.

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Molecular identification of avian influenza virus subtypes H5N1 and H9N2 in birds from farms and live bird markets and in respiratory patients

PeerJ ◽

10.7717/peerj.5473 ◽

2018 ◽

Vol 6 ◽

pp. e5473

Author(s):

Hala M.N. Tolba ◽

Rasha M.M. Abou Elez ◽

Ibrahim Elsohaby ◽

Heba A. Ahmed

Keyword(s):

Amino Acid ◽

Avian Influenza ◽

Cleavage Site ◽

Amino Acid Level ◽

Basic Amino Acid ◽

Influenza Viruses ◽

Pathogenic Avian Influenza ◽

Live Bird Markets ◽

Source Of Infection ◽

Live Bird

Background Avian influenza viruses (AIVs) have been endemic in Egypt since 2006, and the co-circulation of high-pathogenic avian influenza H5N1 and low-pathogenic avian influenza H9N2 subtypes in poultry has been reported; therefore, Egypt is considered a hotspot for the generation of new subtypes and genotypes. We aimed to characterize AIVs circulating on commercial farms and in live bird markets (LBMs) during the winters of 2015 and 2016 in the study area and to identify H5N1 and H9N2 viruses in respiratory patients. Methods In total, 159 samples were collected from ducks, pigeons and quails on farms (n = 59) and in LBMs (n = 100) and screened by real-time RT-PCR for H5N1 and H9N2 subtypes. Clinical and postmortem examination was carried out on birds from the farms. Positive H5N1 samples were sequenced and analysed for mutations. Tracheal swabs were also collected from 89 respiratory patients admitted to respiratory hospitals in the same study area. Results Overall, H5N1 was identified in 13.6% of birds from farms, while it was detected in 17% of birds in LBMs. Subtype H9N2 was only identified from pigeons on farms (6.5%) and LBMs (11.4%). Sequencing of the haemagglutination gene (HA) in nine representative H5N1 isolates revealed a multi-basic amino acid motif at the cleavage site (321-PQGEKRRKKR/GLF-333), which is characteristic of highly pathogenic AIV, in five of our isolates, while the other four isolates showed an amino acid substitution (Q322K) at this cleavage site to make it (321-P K GEKRRKKR/GLF-333). All the isolates belonged to clade 2.2.1.2, and a comparison of HA sequences at the amino acid level showed 98.8–100% homology among the nine isolates, while they showed 94.1–96.1% identity with reference strains and the commonly used vaccine strain in Egypt. Out of 89 respiratory patients, 3.4% were positive for H5N1 and no patients were positive for H9N2. Discussion Our results indicated the circulation of the endemic H5N1 and H9N2 viruses among poultry in 2015 and 2016. Birds on farms and in LBMs are reservoirs playing a role in the dissemination of the virus and producing a public health risk. The application of proper hygienic measures in farms and LBMs to control the exposure of birds and humans to the source of infection along with continuous monitoring of the circulating viruses will provide information on understanding the evolution of the viruses for vaccine studies.

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Isolation and Characterization of Avian Influenza Viruses, Including Highly Pathogenic H5N1, from Poultry in Live Bird Markets in Hanoi, Vietnam, in 2001

Journal of Virology ◽

10.1128/jvi.79.7.4201-4212.2005 ◽

2005 ◽

Vol 79 (7) ◽

pp. 4201-4212 ◽

Cited By ~ 151

Author(s):

Doan C. Nguyen ◽

Timothy M. Uyeki ◽

Samadhan Jadhao ◽

Taronna Maines ◽

Michael Shaw ◽

...

Keyword(s):

Amino Acid ◽

Avian Influenza ◽

Influenza Viruses ◽

Common Source ◽

Avian Influenza Viruses ◽

Highly Pathogenic ◽

Live Bird Markets ◽

Isolation And Characterization ◽

High Amino Acid ◽

Live Bird

ABSTRACT Since 1997, outbreaks of highly pathogenic (HP) H5N1 and circulation of H9N2 viruses among domestic poultry in Asia have posed a threat to public health. To better understand the extent of transmission of avian influenza viruses (AIV) to humans in Asia, we conducted a cross-sectional virologic study in live bird markets (LBM) in Hanoi, Vietnam, in October 2001. Specimens from 189 birds and 18 environmental samples were collected at 10 LBM. Four influenza A viruses of the H4N6 (n = 1), H5N2 (n = 1), and H9N3 (n = 2) subtypes were isolated from healthy ducks for an isolation frequency of over 30% from this species. Two H5N1 viruses were isolated from healthy geese. The hemagglutinin (HA) genes of these H5N1 viruses possessed multiple basic amino acid motifs at the cleavage site, were HP for experimentally infected chickens, and were thus characterized as HP AIV. These HA genes shared high amino acid identities with genes of other H5N1 viruses isolated in Asia during this period, but they were genetically distinct from those of H5N1 viruses isolated from poultry and humans in Vietnam during the early 2004 outbreaks. These viruses were not highly virulent for experimentally infected ducks, mice, or ferrets. These results establish that HP H5N1 viruses with properties similar to viruses isolated in Hong Kong and mainland China circulated in Vietnam as early as 2001, suggest a common source for H5N1 viruses circulating in these Asian countries, and provide a framework to better understand the recent widespread emergence of HP H5N1 viruses in Asia.

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H5N2 Avian Influenza Outbreak in Texas in 2004: the First Highly Pathogenic Strain in the United States in 20 Years?

Journal of Virology ◽

10.1128/jvi.79.17.11412-11421.2005 ◽

2005 ◽

Vol 79 (17) ◽

pp. 11412-11421 ◽

Cited By ~ 67

Author(s):

Chang-Won Lee ◽

David E. Swayne ◽

Jose A. Linares ◽

Dennis A. Senne ◽

David L. Suarez

Keyword(s):

United States ◽

Amino Acid ◽

Avian Influenza ◽

Cleavage Site ◽

Basic Amino Acid ◽

The United States ◽

Influenza Viruses ◽

Single Point Mutation ◽

Highly Pathogenic

ABSTRACT In early 2004, an H5N2 avian influenza virus (AIV) that met the molecular criteria for classification as a highly pathogenic AIV was isolated from chickens in the state of Texas in the United States. However, clinical manifestations in the affected flock were consistent with avian influenza caused by a low-pathogenicity AIV and the representative virus (A/chicken/Texas/298313/04 [TX/04]) was not virulent for experimentally inoculated chickens. The hemagglutinin (HA) gene of the TX/04 isolate was similar in sequence to A/chicken/Texas/167280-4/02 (TX/02), a low-pathogenicity AIV isolate recovered from chickens in Texas in 2002. However, the TX/04 isolate had one additional basic amino acid at the HA cleavage site, which could be attributed to a single point mutation. The TX/04 isolate was similar in sequence to TX/02 isolate in several internal genes (NP, M, and NS), but some genes (PA, PB1, and PB2) had sequence of a clearly different origin. The TX/04 isolate also had a stalk deletion in the NA gene, characteristic of a chicken-adapted AIV. By analyzing viruses constructed by in vitro mutagenesis followed by reverse genetics, we found that the pathogenicity of the TX/04 virus could be increased in vitro and in vivo by the insertion of an additional basic amino acid at the HA cleavage site and not by the loss of a glycosylation site near the cleavage site. Our study provides the genetic and biologic characteristics of the TX/04 isolate, which highlight the complexity of the polygenic nature of the virulence of influenza viruses.

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Sero-Detection of Avian Influenza A/H7 in Nigerian Live-Bird Markets in Plateau State

Nigerian Veterinary Journal ◽

10.4314/nvj.v41i2.7 ◽

2021 ◽

Vol 41 (2) ◽

pp. 161-174

Author(s):

C.N. Chinyere ◽

E.C. Okwor ◽

C.A. Meseko ◽

W.S. Ezema ◽

N.D. Choji ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

Influenza A ◽

Haemagglutination Inhibition ◽

Poultry Production ◽

Live Bird Market ◽

Live Bird Markets ◽

Plateau State ◽

Keywords Influenza ◽

Live Bird

Avian influenza has been reported in domestic birds in Nigeria since 2006 and subtype H5 of the Gs/Gg lineage has continued to be detected up till date. It has been suggested that waterfowls and local birds sold in live-bird markets may be natural reservoir and source of reinfection of different subtype of avian influenza in poultry farms. This study aims at serodetection of avian influenza virus in waterfowls and local birds at live-bird markets in Plateau State, Nigeria. A total of three hundred and nine (309) blood samples were collected over a period of three months and two hundred and ninety-two (292) sera were analysed by c-ELISA for influenza A nucleoprotein using standard protocols. Haemagglutination Inhibition (HI) specific for subtypes H5, H9, and H7 was also carried out using standard protocols on ELISA positive samples. The results showed seroprevalence of 5.14% (n=15) for influenza A. Serotype H7 was thereafter detected by HI in 5 of the 15 influenza A positive samples. The H7 positive sera also reacted with H7N3, H7N4, H7N1 and H7N7 virus strains with HI titre ranging between 1:32 to 1:512. This investigation for the first time showed serological evidence of influenza A subtype H7 in local birds and waterfowls sold at the live bird market in Nigeria. Further virological surveillance to isolate the virus is important in order to better understand influenza virus epidemiology in Nigeria and the potential risk that other subtypesof influenza poses to poultry production and public health. Keywords: Influenza A, subtype H7, serological detection, live bird market, Nigeria.

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