Analytical validation of a real-time reverse transcription polymerase chain reaction test for Pan-American lineage H7 subtype Avian influenza viruses

USGS Publications Warehouse

Spackman, Erica; Ip, Hon S.; Suarez, D.L.; Slemons, R.D.; Stallknecht, D.E.

2008-01-01

A real-time reverse transcription polymerase chain reaction test for the identification of the H7 subtype in North American Avian influenza viruses (AIVs) was first reported in 2002; however, recent AIV surveillance efforts in wild birds and H7 outbreaks in poultry demonstrated that the 2002 test did not detect all H7 AIVs present in North and South America. Therefore, a new test, the 2008 Pan-American H7 test, was developed by using recently available H7 nucleotide sequences. The analytical specificity of the new assay was characterized with an RNA panel composed of 19 H7 viruses from around the world and RNA from all hemagglutinin subtypes except H16. Specificity for North and South American lineage H7 viruses was observed. Assay limits of detection were determined to be between 103 and 104 gene copies per reaction with in vitro transcribed RNA, and 100.0 and 10 0.8 50% egg infectious doses per reaction. The 2008 Pan-American H7 test also was shown to perform similarly to the 2002 test with specimens from chickens experimentally exposed to A/Chicken/BritishColumbia/314514-2/04 H7N3 highly pathogenic AIV. Furthermore, the 2008 test was able to detect 100% (n = 27) of the H7 AIV isolates recovered from North American wild birds in a 2006-2007 sample set (none of which were detected by the 2002 H7 test).

Vaccination with Newcastle disease virus vectored vaccine protects chickens against highly pathogenic H7 avian influenza virus.

PubMed

Schröer, Diana; Veits, Jutta; Grund, Christian; Dauber, Malte; Keil, Günther; Granzow, Harald; Mettenleiter, Thomas C; Römer-Oberdörfer, Angela

2009-06-01

A recombinant Newcastle disease virus (NDV) was engineered to express the hemagglutinin (HA) gene of avian influenza virus (AIV) subtype H7. The HA gene was inserted between the genes encoding NDV fusion and hemagglutinin-neuraminidase proteins. Within the H7 open reading frame, an NDV gene end-like sequence was eliminated by silent mutation. The expression of H7 protein was detected by western blot analysis and indirect immunofluorescence. The existence of H7 protein in the envelope of recombinant Newcastle disease virions was shown by immunoelectron microscopy. The protective efficacy of recombinant NDVH7m against virulent NDV, as well as against highly pathogenic avian influenza virus (HPAIV), was evaluated in specific-pathogen-free chickens. After a single immunization, all chickens developed NDV-specific, as well as AIV H7-specific, antibodies and were completely protected from clinical disease after infection with a lethal dose of virulent NDV or the homologous H7N1 HPAIV, while all control animals died within four days. Shedding of AIV challenge virus was strongly reduced compared to nonvaccinated control birds. Furthermore, the immunized birds developed antibodies against the AIV nucleoprotein after challenge infection. Thus, NDVH7m could be used as a marker vaccine against subtype H7 avian influenza.

Virus-like particles displaying H5, H7, H9 hemagglutinins and N1 neuraminidase elicit protective immunity to heterologous avian influenza viruses in chickens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pushko, Peter, E-mail: ppushko@medigen-usa.com

Avian influenza (AI) viruses circulating in wild birds pose a serious threat to public health. Human and veterinary vaccines against AI subtypes are needed. Here we prepared triple-subtype VLPs that co-localized H5, H7 and H9 antigens derived from H5N1, H7N3 and H9N2 viruses. VLPs also contained influenza N1 neuraminidase and retroviral gag protein. The H5/H7/H9/N1/gag VLPs were prepared using baculovirus expression. Biochemical, functional and antigenic characteristics were determined including hemagglutination and neuraminidase enzyme activities. VLPs were further evaluated in a chicken AI challenge model for safety, immunogenicity and protective efficacy against heterologous AI viruses including H5N2, H7N3 and H9N2 subtypes.more » All vaccinated birds survived challenges with H5N2 and H7N3 highly pathogenic AI (HPAI) viruses, while all controls died. Immune response was also detectable after challenge with low pathogenicity AI (LPAI) H9N2 virus suggesting that H5/H7/H9/N1/gag VLPs represent a promising approach for the development of broadly protective AI vaccine. - Highlights: •VLPs were prepared that co-localized H5, H7 and H9 subtypes in a VLP envelope. •VLPs were characterized including electron microscopy, HA assay and NA enzyme activity. •Experimental VLP vaccine was evaluated in an avian influenza challenge model. •VLPs induced immune responses against heterologous H5, H7 and H9 virus challenges.« less

Novel reassortant H10N7 avian influenza viruses isolated from chickens in Eastern China.

PubMed

Wu, Haibo; Lu, Rufeng; Wu, Xiaoxin; Peng, Xiaorong; Xu, Lihua; Cheng, Linfang; Lu, Xiangyun; Jin, Changzhong; Xie, Tiansheng; Yao, Hangping; Wu, Nanping

2015-04-01

Since 2004, the H10N7 subtype avian influenza virus (AIV) has caused sporadic human infections with variable clinical symptoms world-wide. However, there is limited information pertaining to the molecular characteristics of H10N7 AIVs in China. To more fully characterize the genetic relationships between three novel H10N7 strains isolated from chickens in Eastern China and the strains isolated from birds throughout Asia, and to determine the pathogenicity of the H10N7 isolates in vivo. All eight gene segments from the Chinese H10N7 strains were sequenced and compared with AIV strains available in GenBank. The virulence of the three isolates was determined in chickens and mice. Three H10N7 subtype avian influenza viruses were isolated from chickens in live poultry markets in Eastern China in 2014: (1) A/chicken/Zhejiang/2C66/2014(H10N7) (ZJ-2C66), (2) A/chicken/Zhejiang/2CP2/2014(H10N7) (ZJ-2CP2), and (3) A/chicken/Zhejiang/2CP8/2014(H10N7) (ZJ-2CP8). Phylogenetic analysis indicated that the viruses contained genetic material from H10, H2, H7, and H3 AIV strains that were circulating at the same time. The reassortant H10N7 viruses were found to be minimally pathogenic in chickens and moderately pathogenic in mice. The viruses were able to replicate in mice without prior adaptation. These results suggest that H10N7 surveillance in poultry should be used as an early warning system for avian influenza outbreaks. The novel strains identified here may post a threat to human health in the future if they continue to circulate. Copyright © 2015 Elsevier B.V. All rights reserved.

Highly pathogenic avian influenza virus subtype H5N1 in Mute swans in the Czech Republic.

PubMed

Nagy, Alexander; Machova, Jirina; Hornickova, Jitka; Tomci, Miroslav; Nagl, Ivan; Horyna, Bedrich; Holko, Ivan

2007-02-25

In order to determine the actual prevalence of avian influenza viruses (AIV) in wild birds in the Czech Republic extensive surveillance was carried out between January and April 2006. A total of 2101 samples representing 61 bird species were examined for the presence of influenza A by using PCR, sequencing and cultivation on chicken embryos. AIV subtype H5N1 was detected in 12 Mute swans (Cygnus olor). The viruses were determined as HPAI (highly pathogenic avian influenza) and the hemagglutinin sequence was closely similar to A/mallard/Italy/835/06 and A/turkey/Turkey/1194/05. Following the first H5N1 case, about 300 wild birds representing 33 species were collected from the outbreak region and tested for the presence of AIV without any positive result. This is the first report of highly pathogenic avian influenza subtype H5N1 in the Czech Republic. The potential role of swan as an effective vector of avian influenza virus is also discussed.

Antigenic characterization of H3 subtypes of avian influenza A viruses from North America

USGS Publications Warehouse

Bailey, Elizabeth; Long, Li-Pong; Zhao, Nan; Hall, Jeffrey S.; Baroch, John A; Nolting, Jaqueline; Senter, Lucy; Cunningham, Frederick L; Pharr, G Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J.; Wan, Xiu-Feng

2016-01-01

Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about four units, and each unit corresponds to a 2 log 2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable.

Antigenic Characterization of H3 Subtypes of Avian Influenza A Viruses from North America.

PubMed

Bailey, Elizabeth; Long, Li-Ping; Zhao, Nan; Hall, Jeffrey S; Baroch, John A; Nolting, Jacqueline; Senter, Lucy; Cunningham, Frederick L; Pharr, G Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J; Wan, Xiu-Feng

2016-05-01

Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about four units, and each unit corresponds to a 2 log 2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable.

Highly pathogenic avian influenza A(H7N3) virus in poultry workers, Mexico, 2012.

PubMed

Lopez-Martinez, Irma; Balish, Amanda; Barrera-Badillo, Gisela; Jones, Joyce; Nuñez-García, Tatiana E; Jang, Yunho; Aparicio-Antonio, Rodrigo; Azziz-Baumgartner, Eduardo; Belser, Jessica A; Ramirez-Gonzalez, José E; Pedersen, Janice C; Ortiz-Alcantara, Joanna; Gonzalez-Duran, Elizabeth; Shu, Bo; Emery, Shannon L; Poh, Mee K; Reyes-Teran, Gustavo; Vazquez-Perez, Joel A; Avila-Rios, Santiago; Uyeki, Timothy; Lindstrom, Stephen; Villanueva, Julie; Tokars, Jerome; Ruiz-Matus, Cuitláhuac; Gonzalez-Roldan, Jesus F; Schmitt, Beverly; Klimov, Alexander; Cox, Nancy; Kuri-Morales, Pablo; Davis, C Todd; Diaz-Quiñonez, José Alberto

2013-01-01

We identified 2 poultry workers with conjunctivitis caused by highly pathogenic avian influenza A(H7N3) viruses in Jalisco, Mexico. Genomic and antigenic analyses of 1 isolate indicated relatedness to poultry and wild bird subtype H7N3 viruses from North America. This isolate had a multibasic cleavage site that might have been derived from recombination with host rRNA.

[Oligonucleotide microarray for subtyping avian influenza virus].

PubMed

Xueqing, Han; Xiangmei, Lin; Yihong, Hou; Shaoqiang, Wu; Jian, Liu; Lin, Mei; Guangle, Jia; Zexiao, Yang

2008-09-01

Avian influenza viruses are important human and animal respiratory pathogens and rapid diagnosis of novel emerging avian influenza viruses is vital for effective global influenza surveillance. We developed an oligonucleotide microarray-based method for subtyping all avian influenza virus (16 HA and 9 NA subtypes). In total 25 pairs of primers specific for different subtypes and 1 pair of universal primers were carefully designed based on the genomic sequences of influenza A viruses retrieved from GenBank database. Several multiplex RT-PCR methods were then developed, and the target cDNAs of 25 subtype viruses were amplified by RT-PCR or overlapping PCR for evaluating the microarray. Further 52 oligonucleotide probes specific for all 25 subtype viruses were designed according to published gene sequences of avian influenza viruses in amplified target cDNAs domains, and a microarray for subtyping influenza A virus was developed. Then its specificity and sensitivity were validated by using different subtype strains and 2653 samples from 49 different areas. The results showed that all the subtypes of influenza virus could be identified simultaneously on this microarray with high sensitivity, which could reach to 2.47 pfu/mL virus or 2.5 ng target DNA. Furthermore, there was no cross reaction with other avian respiratory virus. An oligonucleotide microarray-based strategy for detection of avian influenza viruses has been developed. Such a diagnostic microarray will be useful in discovering and identifying all subtypes of avian influenza virus.

Replication and Immunogenicity of Swine, Equine, and Avian H3 Subtype Influenza Viruses in Mice and Ferrets

PubMed Central

Baz, Mariana; Paskel, Myeisha; Matsuoka, Yumiko; Zengel, James; Cheng, Xing; Jin, Hong

2013-01-01

Since it is difficult to predict which influenza virus subtype will cause an influenza pandemic, it is important to prepare influenza virus vaccines against different subtypes and evaluate the safety and immunogenicity of candidate vaccines in preclinical and clinical studies prior to a pandemic. In addition to infecting humans, H3 influenza viruses commonly infect pigs, horses, and avian species. We selected 11 swine, equine, and avian H3 influenza viruses and evaluated their kinetics of replication and ability to induce a broadly cross-reactive antibody response in mice and ferrets. The swine and equine viruses replicated well in the upper respiratory tract of mice. With the exception of one avian virus that replicated poorly in the lower respiratory tract, all of the viruses replicated in mouse lungs. In ferrets, all of the viruses replicated well in the upper respiratory tract, but the equine viruses replicated poorly in the lungs. Extrapulmonary spread was not observed in either mice or ferrets. No single virus elicited antibodies that cross-reacted with viruses from all three animal sources. Avian and equine H3 viruses elicited broadly cross-reactive antibodies against heterologous viruses isolated from the same or other species, but the swine viruses did not. We selected an equine and an avian H3 influenza virus for further development as vaccines. PMID:23576512

Serological surveillance reveals widespread influenza A H7 and H9 subtypes among chicken flocks in Egypt.

PubMed

Afifi, Manal A A; El-Kady, Magdy F; Zoelfakar, Sahar A; Abdel-Moneim, Ahmed Sayed; Abddel-Moneim, Ahmed Sayed

2013-02-01

Multiple avian influenza viruses' subtypes are circulating worldwide possessing serious threat to human populations and considered key contributors to the emergence of human influenza pandemics. This study aimed to identify the potential existence of H7 and H9 avian influenza infections circulating among chicken flocks in Egypt. Serum samples were collected from chicken flocks that experienced respiratory distresses and/or variable mortality rates. H7 and H9 virus infections were screened by haemagglutination inhibition assay using chicken erythrocytes. Serum samples were collected from 9 broiler, 12 breeder and 18 layer flocks. Out of 1,225 examined sera, 417 (34 %) from 14 flocks and 605 (49.4 %) from 21 flocks were found positive for H7 and H9, respectively. Prevalence of both H7 and H9 antibodies were higher in layer followed by breeder then broiler flocks. Special consideration should be paid to control influenza viruses in Egypt, as pandemic influenza strains may develop unnoticed given the presence of subclinical infections, and the possibility of re-assortment with the prevailing endemic H5N1 virus strains in Egypt do exist.

Highly pathogenic avian H5N8 influenza viruses: should we be concerned?

PubMed

Tate, M D

2018-01-01

Avian influenza A viruses pose a constant threat to global human health as sporadic infections continue to occur with associated high mortality rates. To date, a number of avian influenza virus subtypes have infected humans, including H5N1, H7N9, H9N2 and H7N7. The majority of 'bird flu' cases are thought to have arisen from direct contact with infected poultry, particularly in live markets in Asia. 1 While human cases of the H5N8 subtype have not been documented as yet, there is the potential that H5N8 viruses could acquire mutations which favour infection of human cells. There is also the possibility that novel viruses with a tropism for human cells could be generated if H5N8 should reassasort with other circulating avian viruses, such as those of the H5N1 subtype. The emergence of a novel H5N8 virus with the capability of infecting humans could have drastic consequences to global health.

Detection of avian H7N9 influenza A viruses at the Yangtze Delta Region of China during early H7N9 outbreaks

PubMed Central

Li, Yin; Huang, Xin-mei; Zhao, Dong-min; Liu, Yu-zhuo; He, Kong-wang; Liu, Yao-xing; Chen, Chang-hai; Long, Li-Ping; Xu, Yifei; Xie, Xing-xing; Han, Kai-kai; Liu, Xiao-yan; Yang, Jing; Zhang, You-Fa; Fan, Feng; Webby, Richard; Wan, Xiu-Feng

2016-01-01

SUMMARY Since the first H7N9 human case in Shanghai, February 19, 2013, the emerging avian-origin H7N9 influenza A virus has become an epizootic virus in China, posing a potential pandemic threat to public health. From April 2 to April 28, 2013, 422 oral-pharyngeal and cloacal swabs were collected from birds and environmental surfaces at five live poultry markets (LPMs) and 13 backyard poultry farms (BPFs) across three cities, Wuxi, Suzhou, and Nanjing, in the Yangtze Delta Region. A total of 22 isolates were recovered, and 6 were subtyped as H7N9, 9 as H9N2, 4 as H7N9/H9N2, and 3 un-subtyped influenza A viruses. Genomic sequences showed that the HA and NA genes of the H7N9 viruses were similar to those of the H7N9 human isolates as well as other avian origin H7N9 isolates in the region but the PB1, PA, NP, and MP genes of the sequenced viruses were, however, more diverse. Among the four H7N9/H9N2 mixed infections, three were from LPM whereas the other one from the ducks at one BPF, which were H7N9 negative in serological analyses. A survey of the bird trading records of the LPMs and BPFs indicates that trading was a likely route for virus transmission across these regions. Our results suggested that a better biosecurity and more effective vaccination should be implemented in backyard farms besides biosecurity management in LPMs. PMID:27309047

Virus-like particles displaying H5, H7, H9 hemagglutinins and N1 neuraminidase elicit protective immunity to heterologous avian influenza viruses in chickens

PubMed Central

Pushko, Peter; Tretyakova, Irina; Hidajat, Rachmat; Zsak, Aniko; Chrzastek, Klaudia; Tumpey, Terrence M.; Kapczynski, Darrell R.

2016-01-01

Avian influenza (AI) viruses circulating in wild birds pose a serious threat to public health. Human and veterinary vaccines against AI subtypes are needed. Here we prepared triple-subtype VLPs that co-localized H5, H7 and H9 antigens derived from H5N1, H7N3 and H9N2 viruses. VLPs also contained influenza N1 neuraminidase and retroviral gag protein. The H5/H7/H9/N1/gag VLPs were prepared using baculovirus expression. Biochemical, functional and antigenic characteristics were determined including hemagglutination and neuraminidase enzyme activities. VLPs were further evaluated in a chicken AI challenge model for safety, immunogenicity and protective efficacy against heterologous AI viruses including H5N2, H7N3 and H9N2 subtypes. All vaccinated birds survived challenges with H5N2 and H7N3 highly pathogenic AI (HPAI) viruses, while all controls died. Immune response was also detectable after challenge with low pathogenicity AI (LPAI) H9N2 virus suggesting that H5/H7/H9/N1/gag VLPs represent a promising approach for the development of broadly protective AI vaccine. PMID:27936463

Genetically Diverse Low Pathogenicity Avian Influenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerloff, Nancy A.; Khan, Salah Uddin; Zanders, Natosha

Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared tomore » publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. Here these findings, combined with the seven

Genetically Diverse Low Pathogenicity Avian Influenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh.

PubMed

Gerloff, Nancy A; Khan, Salah Uddin; Zanders, Natosha; Balish, Amanda; Haider, Najmul; Islam, Ausraful; Chowdhury, Sukanta; Rahman, Mahmudur Ziaur; Haque, Ainul; Hosseini, Parviez; Gurley, Emily S; Luby, Stephen P; Wentworth, David E; Donis, Ruben O; Sturm-Ramirez, Katharine; Davis, C Todd

2016-01-01

Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared to publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. These findings, combined with the seven year

Genetically Diverse Low Pathogenicity Avian Influenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh

DOE PAGES

Gerloff, Nancy A.; Khan, Salah Uddin; Zanders, Natosha; ...

2016-03-24

Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared tomore » publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. Here these findings, combined with the seven

Genetically Diverse Low Pathogenicity Avian Influenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh

PubMed Central

Gerloff, Nancy A.; Khan, Salah Uddin; Zanders, Natosha; Balish, Amanda; Haider, Najmul; Islam, Ausraful; Chowdhury, Sukanta; Rahman, Mahmudur Ziaur; Haque, Ainul; Hosseini, Parviez; Gurley, Emily S.; Luby, Stephen P.; Wentworth, David E.; Donis, Ruben O.; Sturm-Ramirez, Katharine; Davis, C. Todd

2016-01-01

Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared to publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. These findings, combined with the seven year

Highly pathogenic avian influenza virus subtype H5N1 in mute swans (Cygnus olor) in Central Bosnia.

PubMed

Goletić, Teufik; Gagić, Abdulah; Residbegović, Emina; Kustura, Aida; Kavazović, Aida; Savić, Vladimir; Harder, Timm; Starick, Elke; Prasović, Senad

2010-03-01

In order to determine the actual prevalence of avian influenza viruses (AIVs) in wild birds in Bosnia and Herzegovina, extensive surveillance was carried out between October 2005 and April 2006. A total of 394 samples representing 41 bird species were examined for the presence of influenza A virus using virus isolation in embryonated chicken eggs, PCR, and nucleotide sequencing. AIV subtype H5N1 was detected in two mute swans (Cygnus olor). The isolates were determined to be highly pathogenic avian influenza (HPAI) virus and the hemagglutinin sequence was closely similar to A/Cygnus olor/Astrakhan/ Ast05-2-10/2005 (H5N1). This is the first report of HPAI subtype H5N1 in Bosnia and Herzegovina.

Heterologous Humoral Response against H5N1, H7N3, and H9N2 Avian Influenza Viruses after Seasonal Vaccination in a European Elderly Population

PubMed Central

Sanz, Ivan; Rojo, Silvia; Tamames, Sonia; Eiros, José María; Ortiz de Lejarazu, Raúl

2017-01-01

Avian influenza viruses are currently one of the main threats to human health in the world. Although there are some screening reports of antibodies against these viruses in humans from Western countries, most of these types of studies are conducted in poultry and market workers of Asian populations. The presence of antibodies against avian influenza viruses was evaluated in an elderly European population. An experimental study was conducted, including pre- and post-vaccine serum samples obtained from 174 elderly people vaccinated with seasonal influenza vaccines of 2006–2007, 2008–2009, 2009–2010, and 2010–2011 Northern Hemisphere vaccine campaigns. The presence of antibodies against A/H5N1, A/H7N3, and A/H9N2 avian influenza viruses were tested by using haemaglutination inhibition assays. Globally, heterotypic antibodies were found before vaccination in 2.9% of individuals against A/H5N1, 1.2% against A/H7N3, and 25.9% against A/H9N2. These pre-vaccination antibodies were present at titers ≥1/40 in 1.1% of individuals against A/H5N1, in 1.1% against H7N3, and in 0.6% against the A/H9N2 subtype. One 76 year-old male showed pre-vaccine antibodies (Abs) against those three avian influenza viruses, and another three individuals presented Abs against two different viruses. Seasonal influenza vaccination induced a significant number of heterotypic seroconversions against A/H5N1 (14.4%) and A/H9N2 (10.9%) viruses, but only one seroconversion was observed against the A/H7N3 subtype. After vaccination, four individuals showed Abs titers ≥1/40 against those three avian viruses, and 55 individuals against both A/H5N1 and A/H9N2. Seasonal vaccination is able to induce some weak heterotypic responses to viruses of avian origin in elderly individuals with no previous exposure to them. However, this response did not accomplish the European Medicament Agency criteria for influenza vaccine efficacy. The results of this study show that seasonal vaccines induce a broad

Global alert to avian influenza virus infection: From H5N1 to H7N9

PubMed Central

Poovorawan, Yong; Pyungporn, Sunchai; Prachayangprecha, Slinporn; Makkoch, Jarika

2013-01-01

Outbreak of a novel influenza virus is usually triggered by mutational change due to the process known as ‘antigenic shift’ or re-assortment process that allows animal-to-human or avian-to-human transmission. Birds are a natural reservoir for the influenza virus, and subtypes H5, H7, and H9 have all caused outbreaks of avian influenza in human populations. An especially notorious strain is the HPAI influenza virus H5N1, which has a mortality rate of approximately 60% and which has resulted in numerous hospitalizations, deaths, and significant economic loss. In March 2013, in Eastern China, there was an outbreak of the novel H7N9 influenza virus, which although less pathogenic in avian species, resulted in 131 confirmed cases and 36 deaths in humans over a two-month span. The rapid outbreak of this virus caused global concern but resulted in international cooperation to control the outbreak. Furthermore, cooperation led to valuable research-sharing including genome sequencing of the virus, the development of rapid and specific diagnosis, specimen sharing for future studies, and vaccine development. Although a H7N9 pandemic in the human population is possible due to its rapid transmissibility and extensive surveillance, the closure of the live-bird market will help mitigate the possibility of another H7N9 outbreak. In addition, further research into the source of the outbreak, pathogenicity of the virus, and the development of specific and sensitive detection assays will be essential for controlling and preparing for future H7N9 outbreaks. PMID:23916331

Virus-like particles displaying H5, H7, H9 hemagglutinins and N1 neuraminidase elicit protective immunity to heterologous avian influenza viruses in chickens.

PubMed

Pushko, Peter; Tretyakova, Irina; Hidajat, Rachmat; Zsak, Aniko; Chrzastek, Klaudia; Tumpey, Terrence M; Kapczynski, Darrell R

2017-01-15

Avian influenza (AI) viruses circulating in wild birds pose a serious threat to public health. Human and veterinary vaccines against AI subtypes are needed. Here we prepared triple-subtype VLPs that co-localized H5, H7 and H9 antigens derived from H5N1, H7N3 and H9N2 viruses. VLPs also contained influenza N1 neuraminidase and retroviral gag protein. The H5/H7/H9/N1/gag VLPs were prepared using baculovirus expression. Biochemical, functional and antigenic characteristics were determined including hemagglutination and neuraminidase enzyme activities. VLPs were further evaluated in a chicken AI challenge model for safety, immunogenicity and protective efficacy against heterologous AI viruses including H5N2, H7N3 and H9N2 subtypes. All vaccinated birds survived challenges with H5N2 and H7N3 highly pathogenic AI (HPAI) viruses, while all controls died. Immune response was also detectable after challenge with low pathogenicity AI (LPAI) H9N2 virus suggesting that H5/H7/H9/N1/gag VLPs represent a promising approach for the development of broadly protective AI vaccine. Copyright © 2016. Published by Elsevier Inc.

Development of a Reverse Transcription Loop-Mediated Isothermal Amplification Method for the Rapid Detection of Subtype H7N9 Avian Influenza Virus

PubMed Central

Bao, Hongmei; Zhao, Yuhui; Wang, Yunhe; Xu, Xiaolong; Shi, Jianzhong; Zeng, Xianying; Wang, Xiurong; Chen, Hualan

2014-01-01

A novel influenza A (H7N9) virus has emerged in China. To rapidly detect this virus from clinical samples, we developed a reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the detection of the H7N9 virus. The minimum detection limit of the RT-LAMP assay was 0.01 PFU H7N9 virus, making this method 100-fold more sensitive to the detection of the H7N9 virus than conventional RT-PCR. The H7N9 virus RT-LAMP assays can efficiently detect different sources of H7N9 influenza virus RNA (from chickens, pigeons, the environment, and humans). No cross-reactive amplification with the RNA of other subtype influenza viruses or of other avian respiratory viruses was observed. The assays can effectively detect H7N9 influenza virus RNA in drinking water, soil, cloacal swab, and tracheal swab samples that were collected from live poultry markets, as well as human H7N9 virus, in less than 30 min. These results suggest that the H7N9 virus RT-LAMP assays were efficient, practical, and rapid diagnostic methods for the epidemiological surveillance and diagnosis of influenza A (H7N9) virus from different resource samples. PMID:24689044

Genetic characterization of avian influenza subtype H4N6 and H4N9 from live bird market, Thailand

USDA-ARS?s Scientific Manuscript database

A one year active surveillance program for influenza A viruses among avian species in a live-bird market (LBM) in Bangkok, Thailand was conducted in 2009. Out of 970 samples collected, influenza A virus subtypes H4N6 (n=2) and H4N9 (n=1), were isolated from healthy Muscovy ducks. All three viruses w...

Pathogenesis, Transmissibility, and Ocular Tropism of a Highly Pathogenic Avian Influenza A (H7N3) Virus Associated with Human Conjunctivitis

PubMed Central

Belser, Jessica A.; Davis, C. Todd; Balish, Amanda; Edwards, Lindsay E.; Zeng, Hui; Maines, Taronna R.; Gustin, Kortney M.; Martínez, Irma López; Fasce, Rodrigo; Cox, Nancy J.; Katz, Jacqueline M.

2013-01-01

H7 subtype influenza A viruses, responsible for numerous outbreaks in land-based poultry in Europe and the Americas, have caused over 100 cases of confirmed or presumed human infection over the last decade. The emergence of a highly pathogenic avian influenza H7N3 virus in poultry throughout the state of Jalisco, Mexico, resulting in two cases of human infection, prompted us to examine the virulence of this virus (A/Mexico/InDRE7218/2012 [MX/7218]) and related avian H7 subtype viruses in mouse and ferret models. Several high- and low-pathogenicity H7N3 and H7N9 viruses replicated efficiently in the respiratory tract of mice without prior adaptation following intranasal inoculation, but only MX/7218 virus caused lethal disease in this species. H7N3 and H7N9 viruses were also detected in the mouse eye following ocular inoculation. Virus from both H7N3 and H7N9 subtypes replicated efficiently in the upper and lower respiratory tracts of ferrets; however, only MX/7218 virus infection caused clinical signs and symptoms and was capable of transmission to naive ferrets in a direct-contact model. Similar to other highly pathogenic H7 viruses, MX/7218 replicated to high titers in human bronchial epithelial cells, yet it downregulated numerous genes related to NF-κB-mediated signaling transduction. These findings indicate that the recently isolated North American lineage H7 subtype virus associated with human conjunctivitis is capable of causing severe disease in mice and spreading to naive-contact ferrets, while concurrently retaining the ability to replicate within ocular tissue and allowing the eye to serve as a portal of entry. PMID:23487452

Influenza H7N9 and H9N2 Viruses: Coexistence in Poultry Linked to Human H7N9 Infection and Genome Characteristics

PubMed Central

Yu, Xinfen; Jin, Tao; Cui, Yujun; Pu, Xiaoying; Li, Jun; Xu, Jin; Liu, Guang; Jia, Huijue; Liu, Dan; Song, Shili; Yu, Yang; Xie, Li; Huang, Renjie; Ding, Hua; Kou, Yu; Zhou, Yinyan; Wang, Yayu; Xu, Xun; Yin, Ye; Wang, Jian; Guo, Chenyi; Yang, Xianwei; Hu, Liangping; Wu, Xiaopeng; Wang, Hailong; Liu, Jun; Zhao, Guoqiu; Zhou, Jiyong; Gao, George F.; Yang, Ruifu; Wang, Jun

2014-01-01

ABSTRACT Avian influenza virus A of the novel H7N9 reassortant subtype was recently found to cause severe human respiratory infections in China. Live poultry markets were suspected locations of the human H7N9 infection sources, based on the cases' exposure histories and sequence similarities between viral isolates. To explore the role of live poultry markets in the origin of the novel H7N9 virus, we systematically examined poultry and environmental specimens from local markets and farms in Hangzhou, using real-time reverse transcription-PCR (RT-PCR) as well as high-throughput next-generation sequencing (NGS). RT-PCR identified specimens positive for the H7 and N9 genomic segments in all of the 12 poultry markets epidemiologically linked to 10 human H7N9 cases. Chickens, ducks, and environmental specimens from the markets contained heavily mixed subtypes, including H7, N9, H9, and N2 and sometimes H5 and N1. The idea of the coexistence of H7N9 and H9N2 subtypes in chickens was further supported by metagenomic sequencing. In contrast, human H7N9 infection cases (n = 31) were all negative for H9N2 virus according to real-time RT-PCR. The six internal segments were indistinguishable for the H7N9 and H9N2 viruses. The H9, N2, and internal-segment sequences were very close to the sequence of the H9N2 virus circulating in chickens in China recently. Our results provide direct evidence that H9N2 strains coexisted with the novel human-pathogenic H7N9 influenza virus in epidemiologically linked live poultry markets. Avian influenza A virus of the H9N2 subtype likely made a recent contribution to the evolution of the H7N9 virus and continues to do so. IMPORTANCE Our results suggest that avian influenza A virus of the H9N2 subtype likely made a recent contribution to the evolution of the H7N9 virus, a novel reassortant avian influenza virus A subtype, and continues to do so. The finding helps shed light on how the H7N9 virus emerged, spread, and transmitted to humans. It is of

Influenza H7N9 and H9N2 viruses: coexistence in poultry linked to human H7N9 infection and genome characteristics.

PubMed

Yu, Xinfen; Jin, Tao; Cui, Yujun; Pu, Xiaoying; Li, Jun; Xu, Jin; Liu, Guang; Jia, Huijue; Liu, Dan; Song, Shili; Yu, Yang; Xie, Li; Huang, Renjie; Ding, Hua; Kou, Yu; Zhou, Yinyan; Wang, Yayu; Xu, Xun; Yin, Ye; Wang, Jian; Guo, Chenyi; Yang, Xianwei; Hu, Liangping; Wu, Xiaopeng; Wang, Hailong; Liu, Jun; Zhao, Guoqiu; Zhou, Jiyong; Pan, Jingcao; Gao, George F; Yang, Ruifu; Wang, Jun

2014-03-01

Avian influenza virus A of the novel H7N9 reassortant subtype was recently found to cause severe human respiratory infections in China. Live poultry markets were suspected locations of the human H7N9 infection sources, based on the cases' exposure histories and sequence similarities between viral isolates. To explore the role of live poultry markets in the origin of the novel H7N9 virus, we systematically examined poultry and environmental specimens from local markets and farms in Hangzhou, using real-time reverse transcription-PCR (RT-PCR) as well as high-throughput next-generation sequencing (NGS). RT-PCR identified specimens positive for the H7 and N9 genomic segments in all of the 12 poultry markets epidemiologically linked to 10 human H7N9 cases. Chickens, ducks, and environmental specimens from the markets contained heavily mixed subtypes, including H7, N9, H9, and N2 and sometimes H5 and N1. The idea of the coexistence of H7N9 and H9N2 subtypes in chickens was further supported by metagenomic sequencing. In contrast, human H7N9 infection cases (n = 31) were all negative for H9N2 virus according to real-time RT-PCR. The six internal segments were indistinguishable for the H7N9 and H9N2 viruses. The H9, N2, and internal-segment sequences were very close to the sequence of the H9N2 virus circulating in chickens in China recently. Our results provide direct evidence that H9N2 strains coexisted with the novel human-pathogenic H7N9 influenza virus in epidemiologically linked live poultry markets. Avian influenza A virus of the H9N2 subtype likely made a recent contribution to the evolution of the H7N9 virus and continues to do so. Our results suggest that avian influenza A virus of the H9N2 subtype likely made a recent contribution to the evolution of the H7N9 virus, a novel reassortant avian influenza virus A subtype, and continues to do so. The finding helps shed light on how the H7N9 virus emerged, spread, and transmitted to humans. It is of considerable

Pathogenesis and transmissibility of highly (H7N1) and low (H7N9) pathogenic avian influenza virus infection in red-legged partridge (Alectoris rufa).

PubMed

Bertran, Kateri; Pérez-Ramírez, Elisa; Busquets, Núria; Dolz, Roser; Ramis, Antonio; Darji, Ayub; Abad, Francesc Xavier; Valle, Rosa; Chaves, Aida; Vergara-Alert, Júlia; Barral, Marta; Höfle, Ursula; Majó, Natàlia

2011-02-07

An experimental infection with highly pathogenic avian influenza virus (HPAIV) and low pathogenic avian influenza virus (LPAIV) was carried out in red-legged partridges (Alectoris rufa) in order to study clinical signs, gross and microscopic lesions, and viral distribution in tissues and viral shedding. Birds were infected with a HPAIV subtype H7N1 (A/Chicken/Italy/5093/1999) and a LPAIV subtype H7N9 (A/Anas crecca/Spain/1460/2008). Uninoculated birds were included as contacts in both groups. In HPAIV infected birds, the first clinical signs were observed at 3 dpi, and mortality started at 4 dpi, reaching 100% at 8 dpi. The presence of viral antigen in tissues and viral shedding were confirmed by immunohistochemistry and quantitative real time RT-PCR (qRRT-PCR), respectively, in all birds infected with HPAIV. However, neither clinical signs nor histopathological findings were observed in LPAIV infected partridges. In addition, only short-term viral shedding together with seroconversion was detected in some LPAIV inoculated animals. The present study demonstrates that the red-legged partridge is highly susceptible to the H7N1 HPAIV strain, causing severe disease, mortality and abundant viral shedding and thus contributing to the spread of a potential local outbreak of this virus. In contrast, our results concerning H7N9 LPAIV suggest that the red-legged partridge is not a reservoir species for this virus.

Pathogenesis and transmissibility of highly (H7N1) and low (H7N9) pathogenic avian influenza virus infection in red-legged partridge (Alectoris rufa)

PubMed Central

2011-01-01

An experimental infection with highly pathogenic avian influenza virus (HPAIV) and low pathogenic avian influenza virus (LPAIV) was carried out in red-legged partridges (Alectoris rufa) in order to study clinical signs, gross and microscopic lesions, and viral distribution in tissues and viral shedding. Birds were infected with a HPAIV subtype H7N1 (A/Chicken/Italy/5093/1999) and a LPAIV subtype H7N9 (A/Anas crecca/Spain/1460/2008). Uninoculated birds were included as contacts in both groups. In HPAIV infected birds, the first clinical signs were observed at 3 dpi, and mortality started at 4 dpi, reaching 100% at 8 dpi. The presence of viral antigen in tissues and viral shedding were confirmed by immunohistochemistry and quantitative real time RT-PCR (qRRT-PCR), respectively, in all birds infected with HPAIV. However, neither clinical signs nor histopathological findings were observed in LPAIV infected partridges. In addition, only short-term viral shedding together with seroconversion was detected in some LPAIV inoculated animals. The present study demonstrates that the red-legged partridge is highly susceptible to the H7N1 HPAIV strain, causing severe disease, mortality and abundant viral shedding and thus contributing to the spread of a potential local outbreak of this virus. In contrast, our results concerning H7N9 LPAIV suggest that the red-legged partridge is not a reservoir species for this virus. PMID:21314907

Avian Influenza A (H7N9) Virus

MedlinePlus

... Variant Pandemic Other Asian Lineage Avian Influenza A (H7N9) Virus Language: English (US) Español Recommend on Facebook ... Guidance Laboratorian Guidance H7N9 Images Additional Information Asian H7N9 Outbreak Characterization Asian H7N9 virus infections in poultry ...

Incidence of contamination of live bird markets in Bangladesh with influenza A virus and subtypes H5, H7 and H9.

PubMed

Biswas, P K; Giasuddin, M; Chowdhury, P; Barua, H; Debnath, N C; Yamage, M

2018-06-01

In the absence of robust active surveillance of avian influenza viruses (AIV) affecting poultry in South Asian countries, monitoring of live bird markets (LBMs) can be an alternative. In a longitudinal study of 32 LBM, five environments were sampled as follows: market floor, stall floor, slaughter area, poultry holding cage and water used for meat processing. Samples were taken monthly for 5 months, September 2013-January 2014. Incidence rates (IRs) of LBM contamination with AIV and its subtypes H5, H7 and H9 were assessed. In 10 of the LBM selected, biosecurity measures had been implemented through FAO interventions: the other 22 were non-intervened. Standard procedures were applied to detect AIV and three subtypes in pooled samples (1:5). An LBM was considered positive for AIV or a subtype if at least one of the pooled samples tested positive. The incidence rates of LBM contamination with AIV, H5, H7 and H9 were 0.194 (95% confidence interval (CI) 0.136-0.276), 0.031 (95% CI 0.013-0.075), 0 and 0.175 (95% CI 0.12-0.253) per LBM-month at risk, respectively. The log IR ratio between the FAO-intervened and non-intervened LBM for contamination with AIV was -0.329 (95% CI -1.052 to -0.394, p = .372), 0.598 (95% CI -1.593 to 2.789, p = .593) with subtype H5 and -0.500 (95% CI -1.249 to 0.248, p = .190) with subtype H9, indicating no significant difference. The results obtained suggest that both H5 and H9 were circulating in LBM in Bangladesh in the second half of 2013. The incidence of contamination with H9 was much higher than with H5. © 2017 Blackwell Verlag GmbH.

Validation of a real-time reverse transcriptase-PCR assay for the detection of H7 avian influenza virus

USGS Publications Warehouse

Pedersen, J.; Killian, M.L.; Hines, N.; Senne, D.; Panigrahy, B.; Ip, Hon S.; Spackman, Erica

2010-01-01

This report describes the validation of an avian influenza virus (AIV) H7 subtype-specific real-time reverse transcriptasePCR (rRT-PCR) assay developed at the Southeast Poultry Research Laboratory (SEPRL) for the detection of H7 AI in North and South American wild aquatic birds and poultry. The validation was a collaborative effort by the SEPRL and the National Veterinary Services Laboratories. The 2008 H7 rRT-PCR assay detects 101 50% embryo infectious doses per reaction, or 103104 copies of transcribed H7 RNA. Diagnostic sensitivity and specificity were estimated to be 97.5% and 82.4%, respectively; the assay was shown to be specific for H7 AI when tested with >270 wild birds and poultry viruses. Following validation, the 2008 H7 rRT-PCR procedure was adopted as an official U.S. Department of Agriculture procedure for the detection of H7 AIV. The 2008 H7 assay replaced the previously used (2002) assay, which does not detect H7 viruses currently circulating in wild birds in North and South America. ?? 2010 American Association of Avian Pathologists.

Pathogenesis, Transmissibility, and Tropism of a Highly Pathogenic Avian Influenza A(H7N7) Virus Associated With Human Conjunctivitis in Italy, 2013.

PubMed

Belser, Jessica A; Creager, Hannah M; Zeng, Hui; Maines, Taronna R; Tumpey, Terrence M

2017-09-15

H7 subtype influenza viruses represent a persistent public health threat because of their continued detection in poultry and ability to cause human infection. An outbreak of highly pathogenic avian influenza H7N7 virus in Italy during 2013 resulted in 3 cases of human conjunctivitis. We determined the pathogenicity and transmissibility of influenza A/Italy/3/2013 virus in mouse and ferret models and examined the replication kinetics of this virus in several human epithelial cell types. The moderate virulence observed in mammalian models and the capacity for transmission in a direct contact model underscore the need for continued study of H7 subtype viruses. Published by Oxford University Press for the Infectious Diseases Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Global avian influenza outbreaks 2010-2016: a systematic review of their distribution, avian species and virus subtype.

PubMed

Chatziprodromidou, Ioanna P; Arvanitidou, Malamatenia; Guitian, Javier; Apostolou, Thomas; Vantarakis, George; Vantarakis, Apostolos

2018-01-25

We conducted a systematic review to investigate avian influenza outbreaks and to explore their distribution, upon avian influenza subtype, country, avian species and other relating details as no comprehensive epidemiological analysis of global avian influenza outbreaks from 2010 to 2016 exists. Data was collated from four databases (Scopus, Web of Science Core Correlation, PubMed and SpringerLink electronic journal) and a global electronic reporting system (ProMED mail), using PRISMA and ORION systematic approaches. One hundred seventy three avian influenza virus outbreaks were identified and included in this review, alongside 198 ProMED mail reports. Our research identified that the majority of the reported outbreaks occurred in 2016 (22.2%). These outbreaks were located in China (13.6%) and referred to commercial poultry farms (56.1%). The most common subtype reported in these outbreaks was H5N1 (38.2%), while almost 82.5% of the subtypes were highly pathogenic avian influenza viruses. There were differences noticed between ProMED mail and the scientific literature screened. Avian influenza virus has been proved to be able to contaminate all types of avian species, including commercial poultry farms, wild birds, backyard domestic animals, live poultry, game birds and mixed poultry. The study focused on wet markets, slaughterhouses, wild habitats, zoos and natural parks, in both developed and developing countries. The impact of avian influenza virus seems disproportionate and could potentially burden the already existing disparities in the public health domain. Therefore, a collaboration between all the involved health sectors is considered to be more than necessary.

Pathogenicity and transmission of H5 and H7 highly pathogenic avian influenza viruses in mallards

USDA-ARS?s Scientific Manuscript database

Wild aquatic birds have been associated with the intercontinental spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses of the A/goose/Guangdong/1/96 (Gs/GD) lineage during 2005, 2010 and 2014, but dispersion by wild waterfowl has not been implicated with spread of other HPAI viruses...

Potential for Low-Pathogenic Avian H7 Influenza A Viruses To Replicate and Cause Disease in a Mammalian Model

PubMed Central

Zanin, Mark; Koçer, Zeynep A.; Poulson, Rebecca L.; Gabbard, Jon D.; Howerth, Elizabeth W.; Jones, Cheryl A.; Friedman, Kimberly; Seiler, Jon; Danner, Angela; Kercher, Lisa; McBride, Ryan; Paulson, James C.; Wentworth, David E.; Krauss, Scott; Tompkins, Stephen M.; Stallknecht, David E.

2016-01-01

ABSTRACT H7 subtype influenza A viruses are widely distributed and have been responsible for human infections and numerous outbreaks in poultry with significant impact. Despite this, the disease-causing potential of the precursor low-pathogenic (LP) H7 viruses from the wild bird reservoir has not been investigated. Our objective was to assess the disease-causing potential of 30 LP H7 viruses isolated from wild avian species in the United States and Canada using the DBA/2J mouse model. Without prior mammalian adaptation, the majority of viruses, 27 (90%), caused mortality in mice. Of these, 17 (56.7%) caused 100% mortality and 24 were of pathogenicity similar to that of A/Anhui/1/2013 (H7N9), which is highly pathogenic in mice. Viruses of duck origin were more pathogenic than those of shorebird origin, as 13 of 18 (72.2%) duck origin viruses caused 100% mortality while 4 of 12 (33.3%) shorebird origin viruses caused 100% mortality, despite there being no difference in mean lung viral titers between the groups. Replication beyond the respiratory tract was also evident, particularly in the heart and brain. Of the 16 viruses studied for fecal shedding, 11 were detected in fecal samples. These viruses exhibited a strong preference for avian-type α2,3-linked sialic acids; however, binding to mammalian-type α2,6-linked sialic acids was also detected. These findings indicate that LP avian H7 influenza A viruses are able to infect and cause disease in mammals without prior adaptation and therefore pose a potential public health risk. IMPORTANCE Low-pathogenic (LP) avian H7 influenza A viruses are widely distributed in the avian reservoir and are the precursors of numerous outbreaks of highly pathogenic avian influenza viruses in commercial poultry farms. However, unlike highly pathogenic H7 viruses, the disease-causing potential of LP H7 viruses from the wild bird reservoir has not been investigated. To address this, we studied 30 LP avian H7 viruses isolated from wild

Establishment of a multiplex real-time RT-PCR assay for rapid identification of H6 subtype avian influenza viruses.

PubMed

Yang, Fan; Wu, Haibo; Liu, Fumin; Lu, Xiangyun; Peng, Xiuming; Wu, Nanping

2018-06-01

The H6 subtype avian influenza viruses (AIVs) possess the capacity for zoonotic transmission from avian species to humans. Establishment of a specific, rapid and sensitive method to screen H6 AIVs is necessary. Based on the conserved domain of the matrix and H6 AIV hemagglutinin genes, two TaqMan minor-groove-binder probes and multiplex real-time RT-PCR primers were designed in this study. The multiplex real-time RT-PCR assay developed in this study had high specificity and repeatability and a detection limit of 30 copies per reaction. This rapid diagnostic method will be useful for clinical detection and surveillance of H6 AIVs in China.

Detection of Avian H7N9 Influenza A Viruses in the Yangtze Delta Region of China During Early H7N9 Outbreaks.

PubMed

Li, Yin; Huang, Xin-Mei; Zhao, Dong-Min; Liu, Yu-Zhuo; He, Kong-Wang; Liu, Yao-Xing; Chen, Chang-Hai; Long, Li-Ping; Xu, Yifei; Xie, Xing-Xing; Han, Kai-Kai; Liu, Xiao-Yan; Yang, Jing; Zhang, You-Fa; Fan, Feng; Webby, Richard; Wan, Xiu-Feng

2016-05-01

Since the first H7N9 human case in Shanghai, February 19, 2013, the emerging avian-origin H7N9 influenza A virus has become an epizootic virus in China, posing a potential pandemic threat to public health. From April 2 to April 28, 2013, some 422 oral-pharyngeal and cloacal swabs were collected from birds and environmental surfaces at five live poultry markets (LPMs) and 13 backyard poultry farms (BPFs) across three cities, Wuxi, Suzhou, and Nanjing, in the Yangtze Delta region. In total 22 isolates were recovered, and six were subtyped as H7N9, nine as H9N2, four as H7N9/H9N2, and three unsubtyped influenza A viruses. Genomic sequences showed that the HA and NA genes of the H7N9 viruses were similar to those of the H7N9 human isolates, as well as other avian-origin H7N9 isolates in the region, but the PB1, PA, NP, and MP genes of the sequenced viruses were more diverse. Among the four H7N9/H9N2 mixed infections, three were from LPM, whereas the other one was from the ducks at one BPF, which were H7N9 negative in serologic analyses. A survey of the bird trading records of the LPMs and BPFs indicates that trading was a likely route for virus transmission across these regions. Our results suggested that better biosecurity and more effective vaccination should be implemented in backyard farms, in addition to biosecurity management in LPMs.

Receptor-Binding Profiles of H7 Subtype Influenza Viruses in Different Host Species

PubMed Central

Gambaryan, Alexandra S.; Matrosovich, Tatyana Y.; Philipp, Jennifer; Munster, Vincent J.; Fouchier, Ron A. M.; Cattoli, Giovanni; Capua, Ilaria; Krauss, Scott L.; Webster, Robert G.; Banks, Jill; Bovin, Nicolai V.; Klenk, Hans-Dieter

2012-01-01

Influenza viruses of gallinaceous poultry and wild aquatic birds usually have distinguishable receptor-binding properties. Here we used a panel of synthetic sialylglycopolymers and solid-phase receptor-binding assays to characterize receptor-binding profiles of about 70 H7 influenza viruses isolated from aquatic birds, land-based poultry, and horses in Eurasia and America. Unlike typical duck influenza viruses with non-H7 hemagglutinin (HA), all avian H7 influenza viruses, irrespective of the host species, displayed a poultry-virus-like binding specificity, i.e., preferential binding to sulfated oligosaccharides Neu5Acα2-3Galβ1-4(6-O-HSO3)GlcNAc and Neu5Acα2-3Galβ1-4(Fucα1-3)(6-O-HSO3)GlcNAc. This phenotype correlated with the unique amino acid sequence of the amino acid 185 to 189 loop of H7 HA and seemed to be dependent on ionic interactions between the sulfate group of the receptor and Lys193 and on the lack of sterical clashes between the fucose residue and Gln222. Many North American and Eurasian H7 influenza viruses displayed weak but detectable binding to the human-type receptor moiety Neu5Acα2-6Galβ1-4GlcNAc, highlighting the potential of H7 influenza viruses for avian-to-human transmission. Equine H7 influenza viruses differed from other viruses by preferential binding to the N-glycolyl form of sialic acid. Our data suggest that the receptor-binding site of contemporary H7 influenza viruses in aquatic and terrestrial birds was formed after the introduction of their common precursor from ducks to a new host, presumably, gallinaceous poultry. The uniformity of the receptor-binding profile of H7 influenza viruses in various wild and domestic birds indicates that there is no strong receptor-mediated host range restriction in birds on viruses with this HA subtype. This notion agrees with repeated interspecies transmission of H7 influenza viruses from aquatic birds to poultry. PMID:22345462

Evolutionary dynamics of avian influenza A H7N9 virus across five waves in mainland China, 2013-2017.

PubMed

Xiang, Dan; Pu, Zhiqing; Luo, Tingting; Guo, Fucheng; Li, Xiaobing; Shen, Xuejuan; Irwin, David M; Murphy, Robert W; Liao, Ming; Shen, Yongyi

2018-05-25

Since its emergence in March 2013, novel avian influenza A H7N9 virus has triggered five epidemics of human infections in China. This raises concerns about the pandemic threat of this quickly evolving H7N9 subtype for humans. In this study, we evaluated all available genomes for H7N9 and H9N2 influenza A viruses. Our assessment discovered that H7N9 of the 1st wave had the lowest nucleotide diversity, which then experienced substantial and rapid population expansion from a small founder population. From the 2nd wave, their nucleotide diversity increased quickly, indicating that H7N9 viruses had acquired larger populations and mutations after their initial emergence in 2013. After the phylogeographic divergence in the 2nd wave, although the HA and NA genes from different regions differed, compared to previous epidemics, the evolving H7N9 viruses in the 5th wave lost most of their previous clades. The highly pathogenic avian influenza (HPAI) H7N9 viruses in the 5th wave clustered together, and clustered close to the low pathogenic avian influenza (LPAI) virus isolated from the Pearl River Delta in the 3rd and 4th waves. This result supports the origin of HPAI H7N9 viruses was in the Pearl River Delta. In the 5th wave, although both HPAI and LPAI H7N9 viruses were isolated from the Pearl River Delta, their HA and NA genes were phylogenetically distinct. Copyright © 2018. Published by Elsevier Ltd.

Improved hatchability and efficient protection after in ovo vaccination with live-attenuated H7N2 and H9N2 avian influenza viruses

PubMed Central

2011-01-01

Mass in ovo vaccination with live attenuated viruses is widely used in the poultry industry to protect against various infectious diseases. The worldwide outbreaks of low pathogenic and highly pathogenic avian influenza highlight the pressing need for the development of similar mass vaccination strategies against avian influenza viruses. We have previously shown that a genetically modified live attenuated avian influenza virus (LAIV) was amenable for in ovo vaccination and provided optimal protection against H5 HPAI viruses. However, in ovo vaccination against other subtypes resulted in poor hatchability and, therefore, seemed impractical. In this study, we modified the H7 and H9 hemagglutinin (HA) proteins by substituting the amino acids at the cleavage site for those found in the H6 HA subtype. We found that with this modification, a single dose in ovo vaccination of 18-day old eggs provided complete protection against homologous challenge with low pathogenic virus in ≥70% of chickens at 2 or 6 weeks post-hatching. Further, inoculation of 19-day old egg embryos with 106 EID50 of LAIVs improved hatchability to ≥90% (equivalent to unvaccinated controls) with similar levels of protection. Our findings indicate that the strategy of modifying the HA cleavage site combined with the LAIV backbone could be used for in ovo vaccination against avian influenza. Importantly, with protection conferred as early as 2 weeks post-hatching, with this strategy birds would be protected prior to or at the time of delivery to a farm or commercial operation. PMID:21255403

Transcriptomic characterization of the novel avian-origin influenza A (H7N9) virus: specific host response and responses intermediate between avian (H5N1 and H7N7) and human (H3N2) viruses and implications for treatment options.

PubMed

Josset, Laurence; Zeng, Hui; Kelly, Sara M; Tumpey, Terrence M; Katze, Michael G

2014-02-04

A novel avian-origin H7N9 influenza A virus (IAV) emerged in China in 2013, causing mild to lethal human respiratory infections. H7N9 originated with multiple reassortment events between avian viruses and carries genetic markers of human adaptation. Determining whether H7N9 induces a host response closer to that with human or avian IAV is important in order to better characterize this emerging virus. Here we compared the human lung epithelial cell response to infection with A/Anhui/01/13 (H7N9) or highly pathogenic avian-origin H5N1, H7N7, or human seasonal H3N2 IAV. The transcriptomic response to H7N9 was highly specific to this strain but was more similar to the response to human H3N2 than to that to other avian IAVs. H7N9 and H3N2 both elicited responses related to eicosanoid signaling and chromatin modification, whereas H7N9 specifically induced genes regulating the cell cycle and transcription. Among avian IAVs, the response to H7N9 was closest to that elicited by H5N1 virus. Host responses common to H7N9 and the other avian viruses included the lack of induction of the antigen presentation pathway and reduced proinflammatory cytokine induction compared to that with H3N2. Repression of these responses could have an important impact on the immunogenicity and virulence of H7N9 in humans. Finally, using a genome-based drug repurposing approach, we identified several drugs predicted to regulate the host response to H7N9 that may act as potential antivirals, including several kinase inhibitors, as well as FDA-approved drugs, such as troglitazone and minocycline. Importantly, we validated that minocycline inhibited H7N9 replication in vitro, suggesting that our computational approach holds promise for identifying novel antivirals. Whether H7N9 will be the next pandemic influenza virus or will persist and sporadically infect humans from its avian reservoir, similar to H5N1, is not known yet. High-throughput profiling of the host response to infection allows rapid

Computational approach for predicting the conserved B-cell epitopes of hemagglutinin H7 subtype influenza virus.

PubMed

Wang, Xiangyu; Sun, Qi; Ye, Zhonghua; Hua, Ying; Shao, Na; Du, Yanli; Zhang, Qiwei; Wan, Chengsong

2016-10-01

An avian-origin influenza H7N9 virus epidemic occurred in China in 2013-2014, in which >422 infected people suffered from pneumonia, respiratory distress syndrome and septic shock. H7N9 viruses belong to the H7 subtype of avian-origin influenza viruses (AIV-H7). Hemagglutinin (HA) is a vital membrane protein of AIV that has an important role in host recognition and infection. The epitopes of HA are significant determinants of the regularity of epidemic and viral mutation and recombination mechanisms. The present study aimed to predict the conserved B-cell epitopes of AIV-H7 HA using a bioinformatics approach, including the three most effective epitope prediction softwares available online: Artificial Neural Network based B-cell Epitope Prediction (ABCpred), B-cell Epitope Prediction (BepiPred) and Linear B-cell Epitope Prediction (LBtope). A total of 24 strains of Euro-Asiatic AIV-H7 that had been associated with a serious poultry pandemic or had infected humans in the past 30 years were selected to identify the conserved regions of HA. Sequences were obtained from the National Center for Biotechnology Information and Global Initiative on Sharing Avian Influenza Data databases. Using a combination of software prediction and sequence comparisons, the conserved epitopes of AIV-H7 were predicted and clarified. A total of five conserved epitopes [amino acids (aa) 37-52, 131-142, 215-234, 465-484 and 487-505] with a suitable length, high antigenicity and minimal variation were predicted and confirmed. Each obtained a score of >0.80 in ABCpred, 60% in LBtope and a level of 0.35 in Bepipred. In addition, a representative amino acid change (glutamine 235 -to-leucine 235 ) in the HA protein of the 2013 AIV-H7N9 was discovered. The strategy adopted in the present study may have profound implications on the rapid diagnosis and control of infectious disease caused by H7N9 viruses, as well as by other virulent viruses, such as the Ebola virus.

Isolation and identification of highly pathogenic avian influenza virus subtype H5N1 in peafowl (Pavo cristatus).

PubMed

Ismail, Mahmoud Moussa; Khan, Owais Ahmed; Cattoli, Giovanni; Lu, Huaguang

2010-03-01

An outbreak of highly pathogenic avian influenza (HPAI) virus subtype H5N1 was first diagnosed in a "backyard" flock of peafowl (Pavo cristatus) raised on palace premises in the Kingdom of Saudi Arabia in December 3, 2007. The flock consisted of 40 peafowl, and their ages ranged from 3 to 5 years old. Affected birds suffered from depression, anorexia, and white diarrhea. Four dead birds were submitted for HPAI diagnosis at the Central Veterinary Diagnostic Laboratory in Riyadh. Brain and liver tissues and tracheal and cloacal swabs were taken from the dead birds and processed for a real-time reverse transcriptase (RT)-PCR test and virus isolation in specific-pathogen-free embryonating chicken eggs. The H5N1 subtype of avian influenza virus was isolated from the four dead birds and identified by a real-time RT-PCR before and after egg inoculation. The virus isolates were characterized as HPAI H5N1 virus by sequencing analysis. Phylogenetic comparisons revealed that the H5N1 viruses isolated from peafowl belong to the genetic clade 2.2 according to the World Health Organization nomenclature. The peafowl H5N1 virus falls into 2.2.2 sublineage II and clusters with the H5N1 viruses isolated from poultry in Saudi Arabia in 2007-08.

The NS segment of H5N1 avian influenza viruses (AIV) enhances the virulence of an H7N1 AIV in chickens.

PubMed

Vergara-Alert, Júlia; Busquets, Núria; Ballester, Maria; Chaves, Aida J; Rivas, Raquel; Dolz, Roser; Wang, Zhongfang; Pleschka, Stephan; Majó, Natàlia; Rodríguez, Fernando; Darji, Ayub

2014-01-25

Some outbreaks involving highly pathogenic avian influenza viruses (HPAIV) of subtypes H5 and H7 were caused by avian-to-human transmissions. In nature, different influenza A viruses can reassort leading to new viruses with new characteristics. We decided to investigate the impact that the NS-segment of H5 HPAIV would have on viral pathogenicity of a classical avian H7 HPAIV in poultry, a natural host. We focussed this study based on our previous work that demonstrated that single reassortment of the NS-segment from an H5 HPAIV into an H7 HPAIV changes the ability of the virus to replicate in mammalian hosts. Our present data show that two different H7-viruses containing an NS-segment from H5-types (FPV NS GD or FPV NS VN) show an overall highly pathogenic phenotype compared with the wild type H7-virus (FPV), as characterized by higher viral shedding and earlier manifestation of clinical signs. Correlating with the latter, higher amounts of IFN-β mRNA were detected in the blood of NS-reassortant infected birds, 48 h post-infection (pi). Although lymphopenia was detected in chickens from all AIV-infected groups, also 48 h pi those animals challenged with NS-reassortant viruses showed an increase of peripheral monocyte/macrophage-like cells expressing high levels of IL-1β, as determined by flow cytometry. Taken together, these findings highlight the importance of the NS-segment in viral pathogenicity which is directly involved in triggering antiviral and pro-inflammatory cytokines found during HPAIV pathogenesis in chickens.

Influenza Viral Vectors Expressing Two Kinds of HA Proteins as Bivalent Vaccine Against Highly Pathogenic Avian Influenza Viruses of Clade 2.3.4.4 H5 and H7N9

PubMed Central

Li, Jinping; Hou, Guangyu; Wang, Yan; Wang, Suchun; Peng, Cheng; Yu, Xiaohui; Jiang, Wenming

2018-01-01

The H5 and H7N9 subtypes of highly pathogenic avian influenza viruses (HPAIVs) in China pose a serious challenge to public health and the poultry industry. In this study, a replication competent recombinant influenza A virus of the Í5N1 subtype expressing the H7 HA1 protein from a tri-cistronic NS segment was constructed. A heterologous dimerization domain was used to combine with the truncated NS1 protein of 73 amino acids to increase protein stability. H7 HA1, nuclear export protein coding region, and the truncated NS1 were fused in-frame into a single open reading frame via 2A self-cleaving peptides. The resulting PR8-H5-NS1(73)H7 stably expressed the H5 HA and H7 HA1 proteins, and exhibited similar growth kinetics as the parental PR8-H5 virus in vitro. PR8-H5-NS1(73)H7 induced specific hemagglutination inhibition (HI) antibody against H5, which was comparable to that of the combination vaccine of PR8-H5 and PR8-H7. The HI antibody titers against H7 virus were significantly lower than that by the combination vaccine. PR8-H5-NS1(73)H7 completely protected chickens from challenge with both H5 and H7 HPAIVs. These results suggest that PR8-H5-NS1(73)H7 is highly immunogenic and efficacious against both H5 and H7N9 HPAIVs in chickens. Highlights: - PR8-H5-NS1(73)H7 simultaneously expressed two HA proteins of different avian influenza virus subtypes. - PR8-H5-NS1(73)H7 was highly immunogenic in chickens. - PR8-H5-NS1(73)H7 provided complete protection against challenge with both H5 and H7N9 HPAIVs. PMID:29670587

Pathogenicity and Transmission of H5 and H7 Highly Pathogenic Avian Influenza Viruses in Mallards

PubMed Central

Costa-Hurtado, Mar; Shepherd, Eric; DeJesus, Eric; Smith, Diane; Spackman, Erica; Kapczynski, Darrell R.; Suarez, David L.; Stallknecht, David E.; Swayne, David E.

2016-01-01

ABSTRACT Wild aquatic birds have been associated with the intercontinental spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses of the A/goose/Guangdong/1/96 (Gs/GD) lineage during 2005, 2010, and 2014, but dispersion by wild waterfowl has not been implicated with spread of other HPAI viruses. To better understand why Gs/GD H5 HPAI viruses infect and transmit more efficiently in waterfowl than other HPAI viruses, groups of mallard ducks were challenged with one of 14 different H5 and H7 HPAI viruses, including a Gs/GD lineage H5N1 (clade 2.2) virus from Mongolia, part of the 2005 dispersion, and the H5N8 and H5N2 index HPAI viruses (clade 2.3.4.4) from the United States, part of the 2014 dispersion. All virus-inoculated ducks and contact exposed ducks became infected and shed moderate to high titers of the viruses, with the exception that mallards were resistant to Ck/Pennsylvania/83 and Ck/Queretaro/95 H5N2 HPAI virus infection. Clinical signs were only observed in ducks challenged with the H5N1 2005 virus, which all died, and with the H5N8 and H5N2 2014 viruses, which had decreased weight gain and fever. These three viruses were also shed in higher titers by the ducks, which could facilitate virus transmission and spread. This study highlights the possible role of wild waterfowl in the spread of HPAI viruses. IMPORTANCE The spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses of the Gs/GD lineage by migratory waterfowl is a serious concern for animal and public health. H5 and H7 HPAI viruses are considered to be adapted to gallinaceous species (chickens, turkeys, quail, etc.) and less likely to infect and transmit in wild ducks. In order to understand why this is different with certain Gs/GD lineage H5 HPAI viruses, we compared the pathogenicity and transmission of several H5 and H7 HPAI viruses from previous poultry outbreaks to Gs/GD lineage H5 viruses, including H5N1 (clade 2.2), H5N8 and H5N2 (clade 2.3.4.4) viruses, in

Investigation of avian influenza virus in poultry and wild birds due to novel avian-origin influenza A(H10N8) in Nanchang City, China.

PubMed

Ni, Xiansheng; He, Fenglan; Hu, Maohong; Zhou, Xianfeng; Wang, Bin; Feng, Changhua; Wu, Yumei; Li, Youxing; Tu, Junling; Li, Hui; Liu, Mingbin; Chen, Haiying; Chen, Shengen

2015-01-01

Multiple reassortment events within poultry and wild birds had resulted in the establishment of another novel avian influenza A(H10N8) virus, and finally resulted in human death in Nanchang, China. However, there was a paucity of information on the prevalence of avian influenza virus in poultry and wild birds in Nanchang area. We investigated avian influenza virus in poultry and wild birds from live poultry markets, poultry countyards, delivery vehicles, and wild-bird habitats in Nanchang. We analyzed 1036 samples from wild birds and domestic poultry collected from December 2013 to February 2014. Original biological samples were tested for the presence of avian influenza virus using specific primer and probe sets of H5, H7, H9, H10 and N8 subtypes by real-time RT-PCR. In our analysis, the majority (97.98%) of positive samples were from live poultry markets. Among the poultry samples from chickens and ducks, AIV prevalence was 26.05 and 30.81%, respectively. Mixed infection of different HA subtypes was very common. Additionally, H10 subtypes coexistence with N8 was the most prevalent agent during the emergence of H10N8. This event illustrated a long-term surveillance was so helpful for pandemic preparedness and response. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Poultry farms as a source of avian influenza A (H7N9) virus reassortment and human infection

PubMed Central

Wu, Donglin; Zou, Shumei; Bai, Tian; Li, Jing; Zhao, Xiang; Yang, Lei; Liu, Hongmin; Li, Xiaodan; Yang, Xianda; Xin, Li; Xu, Shuang; Zou, Xiaohui; Li, Xiyan; Wang, Ao; Guo, Junfeng; Sun, Bingxin; Huang, Weijuan; Zhang, Ye; Li, Xiang; Gao, Rongbao; Shen, Bo; Chen, Tao; Dong, Jie; Wei, Hejiang; Wang, Shiwen; Li, Qun; Li, Dexin; Wu, Guizhen; Feng, Zijian; Gao, George F.; Wang, Yu; Wang, Dayan; Fan, Ming; Shu, Yuelong

2015-01-01

Live poultry markets are a source of human infection with avian influenza A (H7N9) virus. On February 21, 2014, a poultry farmer infected with H7N9 virus was identified in Jilin, China, and H7N9 and H9N2 viruses were isolated from the patient's farm. Reassortment between these subtype viruses generated five genotypes, one of which caused the human infection. The date of H7N9 virus introduction to the farm is estimated to be between August 21, 2013 (95% confidence interval [CI] June 6, 2013-October 6, 2013) and September 25, 2013 (95% CI May 28, 2013-January 4, 2014), suggesting that the most likely source of virus introduction was the first batch of poultry purchased in August 2013. The reassortment event that led to the human virus may have occurred between January 2, 2014 (95% CI November 8, 2013-February 12, 2014) and February 12, 2014 (95% CI January 19, 2014-February 18, 2014). Our findings demonstrate that poultry farms could be a source of reassortment between H7N9 virus and H9N2 virus as well as human infection, which emphasizes the importance to public health of active avian influenza surveillance at poultry farms. PMID:25591105

Past, Present, and Possible Future Human Infection with Influenza Virus A Subtype H7

PubMed Central

Belser, Jessica A.; Bridges, Carolyn B.; Katz, Jacqueline M.

2009-01-01

Influenza A subtype H7 viruses have resulted in >100 cases of human infection since 2002 in the Netherlands, Italy, Canada, the United States, and the United Kingdom. Clinical illness from subtype H7 infection ranges from conjunctivitis to mild upper respiratory illness to pneumonia. Although subtype H7 infections have resulted in a smaller proportion of hospitalizations and deaths in humans than those caused by subtype H5N1, some subtype H7 strains appear more adapted for human infection on the basis of their virus-binding properties and illness rates among exposed persons. Moreover, increased isolation of subtype H7 influenza viruses from poultry and the ability of this subtype to cause severe human disease underscore the need for continued surveillance and characterization of these viruses. We review the history of human infection caused by subtype H7. In addition, we discuss recently identified molecular correlates of subtype H7 virus pathogenesis and assess current measures to prevent future subtype H7 virus infection. PMID:19523282

Studying the pathogenicity of avian influenza viruses in different avian species

USDA-ARS?s Scientific Manuscript database

Avian influenza (AI) viruses are significant pathogens of domestic poultry worldwide. Wild aquatic birds are the primordial reservoirs of AI viruses, which are classified as low pathogenic (LP) and can be any of the 16 hemagglutinin subtypes (H1-16). Circulation of H5 or H7 subtype LPAI viruses in...

The NS segment of H5N1 avian influenza viruses (AIV) enhances the virulence of an H7N1 AIV in chickens

PubMed Central

2014-01-01

Some outbreaks involving highly pathogenic avian influenza viruses (HPAIV) of subtypes H5 and H7 were caused by avian-to-human transmissions. In nature, different influenza A viruses can reassort leading to new viruses with new characteristics. We decided to investigate the impact that the NS-segment of H5 HPAIV would have on viral pathogenicity of a classical avian H7 HPAIV in poultry, a natural host. We focussed this study based on our previous work that demonstrated that single reassortment of the NS-segment from an H5 HPAIV into an H7 HPAIV changes the ability of the virus to replicate in mammalian hosts. Our present data show that two different H7-viruses containing an NS-segment from H5–types (FPV NS GD or FPV NS VN) show an overall highly pathogenic phenotype compared with the wild type H7–virus (FPV), as characterized by higher viral shedding and earlier manifestation of clinical signs. Correlating with the latter, higher amounts of IFN-β mRNA were detected in the blood of NS-reassortant infected birds, 48 h post-infection (pi). Although lymphopenia was detected in chickens from all AIV-infected groups, also 48 h pi those animals challenged with NS-reassortant viruses showed an increase of peripheral monocyte/macrophage-like cells expressing high levels of IL-1β, as determined by flow cytometry. Taken together, these findings highlight the importance of the NS-segment in viral pathogenicity which is directly involved in triggering antiviral and pro-inflammatory cytokines found during HPAIV pathogenesis in chickens. PMID:24460592

Determining the phylogenetic and phylogeographic origin of highly pathogenic avian influenza (H7N3) in Mexico.

PubMed

Lu, Lu; Lycett, Samantha J; Leigh Brown, Andrew J

2014-01-01

Highly pathogenic (HP) avian influenza virus (AIV) H7N3 outbreaks occurred 3 times in the Americas in the past 10 years and caused severe economic loss in the affected regions. In June/July 2012, new HP H7N3 outbreaks occurred at commercial farms in Jalisco, Mexico. Outbreaks continued to be identified in neighbouring states in Mexico till August 2013. To explore the origin of this outbreak, time resolved phylogenetic trees were generated from the eight segments of full-length AIV sequences in North America using BEAST. Location, subtype, avian host species and pathogenicity were modelled as discrete traits upon the trees using continuous time Markov chains. A further joint analysis among segments was performed using a hierarchical phylogenetic model (HPM) which allowed trait rates (location, subtype, host species) to be jointly inferred across different segments. The complete spatial diffusion process was visualised through virtual globe software. Our result indicated the Mexico HP H7N3 originated from the large North America low pathogenicity AIV pool through complicated reassortment events. Different segments were contributed by wild waterfowl from different N. American flyways. Five of the eight segments (HA, NA, NP, M, NS) were introduced from wild birds migrating along the central North American flyway, and PB2, PB1 and PA were introduced via the western North American flyway. These results highlight a potential role for Mexico as a hotspot of virus reassortment as it is where wild birds from different migration routes mix during the winter.

Determining the Phylogenetic and Phylogeographic Origin of Highly Pathogenic Avian Influenza (H7N3) in Mexico

PubMed Central

Lu, Lu; Lycett, Samantha J.; Leigh Brown, Andrew J.

2014-01-01

Highly pathogenic (HP) avian influenza virus (AIV) H7N3 outbreaks occurred 3 times in the Americas in the past 10 years and caused severe economic loss in the affected regions. In June/July 2012, new HP H7N3 outbreaks occurred at commercial farms in Jalisco, Mexico. Outbreaks continued to be identified in neighbouring states in Mexico till August 2013. To explore the origin of this outbreak, time resolved phylogenetic trees were generated from the eight segments of full-length AIV sequences in North America using BEAST. Location, subtype, avian host species and pathogenicity were modelled as discrete traits upon the trees using continuous time Markov chains. A further joint analysis among segments was performed using a hierarchical phylogenetic model (HPM) which allowed trait rates (location, subtype, host species) to be jointly inferred across different segments. The complete spatial diffusion process was visualised through virtual globe software. Our result indicated the Mexico HP H7N3 originated from the large North America low pathogenicity AIV pool through complicated reassortment events. Different segments were contributed by wild waterfowl from different N. American flyways. Five of the eight segments (HA, NA, NP, M, NS) were introduced from wild birds migrating along the central North American flyway, and PB2, PB1 and PA were introduced via the western North American flyway. These results highlight a potential role for Mexico as a hotspot of virus reassortment as it is where wild birds from different migration routes mix during the winter. PMID:25226523

Low immunogenicity predicted for emerging avian-origin H7N9

PubMed Central

De Groot, Anne S.; Ardito, Matthew; Terry, Frances; Levitz, Lauren; Ross, Ted; Moise, Leonard; Martin, William

2013-01-01

A new avian-origin influenza virus emerged near Shanghai in February 2013, and by the beginning of May it had caused over 130 human infections and 36 deaths. Human-to-human transmission of avian-origin H7N9 influenza A has been limited to a few family clusters, but the high mortality rate (27%) associated with human infection has raised concern about the potential for this virus to become a significant human pathogen. European, American, and Asian vaccine companies have already initiated the process of cloning H7 antigens such as hemagglutinin (HA) into standardized vaccine production vehicles. Unfortunately, previous H7 HA-containing vaccines have been poorly immunogenic. We used well-established immunoinformatics tools to analyze the H7N9 protein sequences and compare their T cell epitope content to other circulating influenza A strains as a means of estimating the immunogenic potential of the new influenza antigen. We found that the HA proteins derived from closely related human-derived H7N9 strains contain fewer T cell epitopes than other recently circulating strains of influenza, and that conservation of T cell epitopes with other strains of influenza was very limited. Here, we provide a detailed accounting of the type and location of T cell epitopes contained in H7N9 and their conservation in other H7 and circulating (A/California/07/2009, A/Victoria/361/2011, and A/Texas/50/2012) influenza A strains. Based on this analysis, avian-origin H7N9 2013 appears to be a “stealth” virus, capable of evading human cellular and humoral immune response. Should H7N9 develop pandemic potential, this analysis predicts that novel strategies for improving vaccine immunogenicity for this unique low-immunogenicity strain of avian-origin influenza will be urgently needed. PMID:23807079

Characterization of a reassortant H11N9 subtype avian influenza virus isolated from bean goose along the East Asian-Australian flyway.

PubMed

Yao, Yanfeng; Shao, Zhiyong; He, Bin; Yang, Wenhai; Chen, Jianjun; Zhang, Tao; Chen, Xiabing; Chen, Jie

2017-02-01

During the surveillance of avian influenza viruses in the Dongxi Lake wetland of Hubei in 2015-2016, an H11N9 avian influenza virus was isolated from a bean goose (Anser fabalis). Phylogenetic analysis showed that the HA gene of this isolate belongs to the North American lineage; however, the NA and the internal genes of the isolate were generated from the Eurasian lineage. This strain had reduced pathogenicity in mice and was capable of replication in the mouse lung without prior adaptation. This is the first report detecting H11N9 subtype influenza virus from migratory birds in central China. These findings highlight the transmission of avian influenza virus along the East Asian-Australian flyway and the need for continuing surveillance in central China.

Preferential recognition of avian-like receptors in human influenza A H7N9 viruses.

PubMed

Xu, Rui; de Vries, Robert P; Zhu, Xueyong; Nycholat, Corwin M; McBride, Ryan; Yu, Wenli; Paulson, James C; Wilson, Ian A

2013-12-06

The 2013 outbreak of avian-origin H7N9 influenza in eastern China has raised concerns about its ability to transmit in the human population. The hemagglutinin glycoprotein of most human H7N9 viruses carries Leu(226), a residue linked to adaptation of H2N2 and H3N2 pandemic viruses to human receptors. However, glycan array analysis of the H7 hemagglutinin reveals negligible binding to humanlike α2-6-linked receptors and strong preference for a subset of avian-like α2-3-linked glycans recognized by all avian H7 viruses. Crystal structures of H7N9 hemagglutinin and six hemagglutinin-glycan complexes have elucidated the structural basis for preferential recognition of avian-like receptors. These findings suggest that the current human H7N9 viruses are poorly adapted for efficient human-to-human transmission.

Antigenic and Molecular Characterization of Avian Influenza A(H9N2) Viruses, Bangladesh

PubMed Central

Shanmuganatham, Karthik; Feeroz, Mohammed M.; Jones-Engel, Lisa; Smith, Gavin J.D.; Fourment, Mathieu; Walker, David; McClenaghan, Laura; Alam, S.M. Rabiul; Hasan, M. Kamrul; Seiler, Patrick; Franks, John; Danner, Angie; Barman, Subrata; McKenzie, Pamela; Krauss, Scott; Webby, Richard J.

2013-01-01

Human infection with avian influenza A(H9N2) virus was identified in Bangladesh in 2011. Surveillance for influenza viruses in apparently healthy poultry in live-bird markets in Bangladesh during 2008–2011 showed that subtype H9N2 viruses are isolated year-round, whereas highly pathogenic subtype H5N1 viruses are co-isolated with subtype H9N2 primarily during the winter months. Phylogenetic analysis of the subtype H9N2 viruses showed that they are reassortants possessing 3 gene segments related to subtype H7N3; the remaining gene segments were from the subtype H9N2 G1 clade. We detected no reassortment with subtype H5N1 viruses. Serologic analyses of subtype H9N2 viruses from chickens revealed antigenic conservation, whereas analyses of viruses from quail showed antigenic drift. Molecular analysis showed that multiple mammalian-specific mutations have become fixed in the subtype H9N2 viruses, including changes in the hemagglutinin, matrix, and polymerase proteins. Our results indicate that these viruses could mutate to be transmissible from birds to mammals, including humans. PMID:23968540

Optical fiber sensor based on surface plasmon resonance for rapid detection of avian influenza virus subtype H6: Initial studies.

PubMed

Zhao, Xihong; Tsao, Yu-Chia; Lee, Fu-Jung; Tsai, Woo-Hu; Wang, Ching-Ho; Chuang, Tsung-Liang; Wu, Mu-Shiang; Lin, Chii-Wann

2016-07-01

A side-polished fiber optic surface plasmon resonance (SPR) sensor was fabricated to expose the core surface and then deposited with a 40 nm thin gold film for the near surface sensing of effective refractive index changes with surface concentration or thickness of captured avian influenza virus subtype H6. The detection surface of the SPR optical fiber sensor was prepared through the plasma modification method for binding a self-assembled monolayer of isopropanol chemically on the gold surface of the optical fiber. Subsequently, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide/N-hydroxysuccinimide was activated to enable EB2-B3 monoclonal antibodies to capture A/chicken/Taiwan/2838V/00 (H6N1) through a flow injection system. The detection limit of the fabricated optical fiber sensor for A/chicken/Taiwan/2838V/00 was 5.14 × 10(5) EID50/0.1 mL, and the response time was 10 min on average. Moreover, the fiber optic sensor has the advantages of a compact size and low cost, thus rendering it suitable for online and remote sensing. The results indicated that the optical fiber sensor can be used for epidemiological surveillance and diagnosing of avian influenza subtype H6 rapidly. Copyright © 2016 Elsevier B.V. All rights reserved.

Avian influenza virus with Hemagglutinin-Neuraminidase combination H8N8, isolated in Russia

USDA-ARS?s Scientific Manuscript database

This study reports the genome sequence of an avian influenza virus (AIV) subtype H8N8 isolated in Russia. The genome analysis shows that all genes belong to AIV Eurasian lineages. The PB2 gene was similar to a Mongolian low pathogenic (LP) AIV H7N1 and a Chinese high pathogenic (HP) AIV H5N2....

Isolation of H5N6, H7N9 and H9N2 avian influenza A viruses from air sampled at live poultry markets in China, 2014 and 2015

PubMed Central

Zhou, Jie; Wu, Jie; Zeng, Xianqiao; Huang, Guofeng; Zou, Lirong; Song, Yingchao; Gopinath, Divya; Zhang, Xin; Kang, Min; Lin, Jinyan; Cowling, Benjamin J; Lindsley, William G.; Ke, Changwen; Peiris, Joseph Sriyal Malik; Yen, Hui-Ling

2016-01-01

Zoonotic infections by avian influenza viruses occur at the human–poultry interface, but the modes of transmission have not been fully investigated. We assessed the potential for airborne and fomite transmission at live poultry markets in Guangzhou city and in Hong Kong Special Administrative Region (SAR), China, during 2014 and 2015. Viral genome and infectious avian influenza A viruses of H5N6, H7N9, and H9N2 subtypes were detected predominantly from particles larger or equal to 1 μm in diameter in the air sampled with cyclone-based bioaerosol samplers at the live poultry markets in Guangzhou. Influenza A(H9N2) viruses were ubiquitously isolated every month during the study period from air and environmental swabs, and different lineages of H9N2 virus were isolated from markets where chickens and minor land-based poultry were sold. The use of de-feathering devices increased the quantity of virus-laden airborne particles while market closure reduced the amount of such particles. The results highlight the possibility of airborne transmission of avian influenza viruses among poultry or from poultry to humans within such settings. This may explain epidemiological observations in which some patients with H7N9 infection reported being in markets but no direct contact with live poultry or poultry stalls. PMID:27608369

Isolation of H5N6, H7N9 and H9N2 avian influenza A viruses from air sampled at live poultry markets in China, 2014 and 2015.

PubMed

Zhou, Jie; Wu, Jie; Zeng, Xianqiao; Huang, Guofeng; Zou, Lirong; Song, Yingchao; Gopinath, Divya; Zhang, Xin; Kang, Min; Lin, Jinyan; Cowling, Benjamin J; Lindsley, William G; Ke, Changwen; Peiris, Joseph Sriyal Malik; Yen, Hui-Ling

2016-09-01

Zoonotic infections by avian influenza viruses occur at the human-poultry interface, but the modes of transmission have not been fully investigated. We assessed the potential for airborne and fomite transmission at live poultry markets in Guangzhou city and in Hong Kong Special Administrative Region (SAR), China, during 2014 and 2015. Viral genome and infectious avian influenza A viruses of H5N6, H7N9, and H9N2 subtypes were detected predominantly from particles larger or equal to 1 μm in diameter in the air sampled with cyclone-based bioaerosol samplers at the live poultry markets in Guangzhou. Influenza A(H9N2) viruses were ubiquitously isolated every month during the study period from air and environmental swabs, and different lineages of H9N2 virus were isolated from markets where chickens and minor land-based poultry were sold. The use of de-feathering devices increased the quantity of virus-laden airborne particles while market closure reduced the amount of such particles. The results highlight the possibility of airborne transmission of avian influenza viruses among poultry or from poultry to humans within such settings. This may explain epidemiological observations in which some patients with H7N9 infection reported being in markets but no direct contact with live poultry or poultry stalls. This article is copyright of The Authors, 2016.

Isolation and genetic characterization of novel reassortant H6N6 subtype avian influenza viruses isolated from chickens in eastern China.

PubMed

Wu, Haibo; Lu, Rufeng; Peng, Xiuming; Peng, Xiaorong; Cheng, Linfang; Jin, Changzhong; Lu, Xiangyun; Xie, Tiansheng; Yao, Hangping; Wu, Nanping

2016-07-01

H6 subtype avian influenza viruses (AIVs) possess the ability to cross the species barrier to infect mammals and pose a threat to human health. From June 2014 to July 2015, 12 H6N6 AIVs were isolated from chickens in live-poultry markets in Zhejiang Province, Eastern China. Phylogenetic analysis showed that these isolates received their genes from H6 and H9N2 subtype AIVs of poultry in China. These novel reassortant viruses showed moderate pathogenicity in mice and were able to replicate in mice without prior adaptation. Considering that novel reassorted H6N6 viruses were isolated from chickens in this study, it is possible that these chickens play an important role in the generation of novel reassorted H6N6 AIVs, and these results emphasize the need for continued surveillance of the H6N6 AIVs circulating in poultry.

Coexistence of Avian Influenza Virus H10 and H9 Subtypes among Chickens in Live Poultry Markets during an Outbreak of Infection with a Novel H10N8 Virus in Humans in Nanchang, China.

PubMed

Hu, Maohong; Li, Xiaodan; Ni, Xiansheng; Wu, Jingwen; Gao, Rongbao; Xia, Wen; Wang, Dayan; He, Fenglan; Chen, Shengen; Liu, Yangqing; Guo, Shuangli; Li, Hui; Shu, Yuelong; Bethel, Jeffrey W; Liu, Mingbin; Moore, Justin B; Chen, Haiying

2015-01-01

Infection with the novel H10N8 virus in humans has raised concerns about its pandemic potential worldwide. We report the results of a cross-sectional study of avian influenza viruses (AIVs) in live poultry markets (LPMs) in Nanchang, China, after the first human case of H10N8 virus infection was reported in the city. A total of 201 specimens tested positive for AIVs among 618 samples collected from 24 LPMs in Nanchang from December 2013 to January 2014. We found that the LPMs were heavily contaminated by AIVs, with H9, H10, and H5 being the predominant subtypes and more than half of the LPMs providing samples that were positive for the H10 subtype. Moreover, the coexistence of different subtypes was common in LPMs. Of the 201 positive samples, 20.9% (42/201) had mixed infections with AIVs of different HA subtypes. Of the 42 mixed infections, 50% (21/42) showed the coexistence of the H9 and H10 subtypes, with or without H5, and were from chicken samples. This indicated that the H10N8 virus probably originated from segment reassortment of the H9 and H10 subtypes.

[Risk related to the transmission of H5N1 subtype avian influenza virus in the environment of poultry markets in Changsha, China].

PubMed

Zhang, Ru-sheng; Ou, Xin-hua; Song, Ke-yun; Yuan, Jie; Chen, Tian-mu; Xiao, Shan; Sun, Bian-cheng

2012-08-01

To investigate the risk of H5N1 subtype avian influenza virus (AIV) transmission in the poultry market environment in Changsha city. H5N1 antibody levels among the groups related occupational exposure and AIV nucleic acid in the environment of poultry markets were detected. The characteristics of haemagglutinin (HA) genes of H5N1 AIV in the environment were analyzed. One district and one county from Changsha city were selected randomly and two poultry markets at inner city or township levels were selected in the same district or county respectively. H5N1 antibody of the occupational exposure groups in the poultry market was tested and AIV nucleic acid in the poultry market environment monitored. One hundred and two blood samples of the occupational exposure groups were tested for H5N1 antibody with single radioimmunoassay diffusion hemolysis (SRH) while 160 environment samples (from sewage, birds stools, feathers and smearing samples of poultry cages) in the poultry market were also detected for AIV nucleic acid with real-time PCR method. Four sewage samples of H5N1 subtype AIV were collected from poultry markets in Changsha, and the HA genes of H5N1 subtype AIV amplified by RT-PCR and then sequenced with TA cloning. Amino acid sequence alignment and phylogenetic tree analysis were conducted by Lasergene and Mega 5.0 software. The results through H5N1 antibody monitoring program showed that H5N1 antibody positive rates from workers were 25.5% (26/102), 50.0% (9/18) and 25.4% (17/67) respectively in the poultry markets of township and inner cities. H5N1 antibody positive rate in the township poultry markets was higher than in the inner cities poultry markets. from the surveillance on AIV nucleic acid showed that the overall H5 subtype positive rate in Changsha poultry markets was 31.3% (50/160), and the positive rate of townships poultry markets was 37.3% (31/83), which were both higher than those from the inner cities poultry markets (24.7%, 19/77). H5 subtype AIV

Novel Reassortant H3N2 Avian Influenza Virus Isolated from Domestic Ducks in Eastern China in 2016

PubMed Central

Sun, Wenqiang; Li, Jiaxin; Hu, Jiao; Jiang, Daxiu; Ge, Zhichuang; Xing, Chaonan; Wang, Xiaoquan; Gu, Min; Liu, Xiaowen; Hu, Shunlin

2017-01-01

ABSTRACT H3 subtype avian influenza virus (AIV) poses a great threat to public health, and so investigating its epidemiology is of great importance. A novel reassortant H3N2 AIV strain was isolated from a live poultry market in eastern China. The strain’s genes originated from H1N1, H3, and H7 AIVs. Thus, the genome information of the H3N2 isolate will help to investigate further the epidemiology of H3 subtype AIVs in China. PMID:29192070

Avian influenza viruses in humans.

PubMed

Malik Peiris, J S

2009-04-01

Past pandemics arose from low pathogenic avian influenza (LPAI) viruses. In more recent times, highly pathogenic avian influenza (HPAI) H5N1, LPAI H9N2 and both HPAI and LPAI H7 viruses have repeatedly caused zoonotic disease in humans. Such infections did not lead to sustained human-to-human transmission. Experimental infection of human volunteers and seroepidemiological studies suggest that avian influenza viruses of other subtypes may also infect humans. Viruses of the H7 subtype appear to have a predilection to cause conjunctivitis and influenza-like illness (ILI), although HPAI H7N7 virus has also caused fatal respiratory disease. Low pathogenic H9N2 viruses have caused mild ILI and its occurrence may be under-recognised for this reason. In contrast, contemporary HPAI H5N1 viruses are exceptional in their virulence for humans and differ from human seasonal influenza viruses in their pathogenesis. Patients have a primary viral pneumonia progressing to acute respiratory distress syndrome (ARDS) and multiple organ dysfunction syndrome. Over 380 human cases have been confirmed to date, with an overall case fatality of 63%. The zoonotic transmission of avian influenza is a rare occurrence, butthe greater public health concern is the adaptation of such viruses to efficient human transmission, which could lead to a pandemic. A better understanding of the ecology of avian influenza viruses and the biological determinants of transmissibility and pathogenicity in humans is important for pandemic preparedness.

Prevalence of Multiple Subtypes of Avian Influenza Virus Antibodies in Egg Yolks of Mallard ( Anas platyrhynchos) and White-winged Terns ( Chlidonias leucopterus) in the Northeastern Republic of China.

PubMed

Chen, Xuelong; Qi, Yanping; Wang, Honghai; Wang, Yafei; Wang, Haixia; Ni, Hongbo

2018-06-12

Wild birds are natural hosts of avian influenza viruses (AIV) and can transmit viruses to poultry and other species. To monitor the prevalence of AIV antibodies, 211 eggs from wild Mallards ( Anas platyrhynchos) and 177 from wild White-winged Terns ( Chlidonias leucopterus) were collected from Zhalong Wetland and Xianghai Wetland in northeastern Republic of China from April to September, 2016. A hemagglutinin inhibition test detected the presence of H1, H3, H5, and H7 subtype-specific antibodies. The prevalences of AIV antibodies of subtypes H1 and H3 were relatively high while the prevalences of H5 and H7 AIV subtype antibody were low. In Zhalong Wetland, the prevalence of H1 AIV subtype antibody in Mallards was the highest, with a percentage of 11.0%. Prevalence of all AIV subtype-specific antibodies in Mallard was higher than those in White-winged Terns.

Convergent Evolution of Human-Isolated H7N9 Avian Influenza A Viruses.

PubMed

Xiang, Dan; Shen, Xuejuan; Pu, Zhiqing; Irwin, David M; Liao, Ming; Shen, Yongyi

2018-05-05

Avian influenza A virus H7N9 has caused 5 epidemic waves of human infections in China since 2013. Avian influenza A viruses may face strong selection to adapt to novel conditions when establishing themselves in humans. In this study, we sought to determine whether adaptive evolution had occurred in human-isolated H7N9 viruses. We evaluated all available genomes of H7N9 avian influenza A virus. Maximum likelihood trees were separately reconstructed for all 8 genes. Signals of positive selection and convergent evolution were then detected on branches that lead to changes in host tropism (from avian to human). We found that 3 genes had significant signals of positive selection (all of them P < .05). In addition, we detected 34 sites having significant signals for parallel evolution in 8 genes (all of them P < .05), including 7 well-known sites (Q591K, E627K, and D701N in PB2 gene; R156K, V202A, and L244Q in HA; and R289K in NA) that play roles in crossing species barriers for avian influenza A viruses. Our study suggests that, during infection in humans, H7N9 viruses have undergone adaptive evolution to adapt to their new host environment and that the sites where parallel evolution occurred might play roles in crossing species barriers and respond to the new selection pressures arising from their new host environments.

Comparative study of the hemagglutinin and neuraminidase genes of influenza A virus H3N2, H9N2, and H5N1 subtypes using bioinformatics techniques.

PubMed

Ahn, Insung; Son, Hyeon S

2007-07-01

To investigate the genomic patterns of influenza A virus subtypes, such as H3N2, H9N2, and H5N1, we collected 1842 sequences of the hemagglutinin and neuraminidase genes from the NCBI database and parsed them into 7 categories: accession number, host species, sampling year, country, subtype, gene name, and sequence. The sequences that were isolated from the human, avian, and swine populations were extracted and stored in a MySQL database for intensive analysis. The GC content and relative synonymous codon usage (RSCU) values were calculated using JAVA codes. As a result, correspondence analysis of the RSCU values yielded the unique codon usage pattern (CUP) of each subtype and revealed no extreme differences among the human, avian, and swine isolates. H5N1 subtype viruses exhibited little variation in CUPs compared with other subtypes, suggesting that the H5N1 CUP has not yet undergone significant changes within each host species. Moreover, some observations may be relevant to CUP variation that has occurred over time among the H3N2 subtype viruses isolated from humans. All the sequences were divided into 3 groups over time, and each group seemed to have preferred synonymous codon patterns for each amino acid, especially for arginine, glycine, leucine, and valine. The bioinformatics technique we introduce in this study may be useful in predicting the evolutionary patterns of pandemic viruses.

Novel Reassortant H3N2 Avian Influenza Virus Isolated from Domestic Ducks in Eastern China in 2016.

PubMed

Sun, Wenqiang; Li, Jiaxin; Hu, Jiao; Jiang, Daxiu; Ge, Zhichuang; Xing, Chaonan; Wang, Xiaoquan; Gu, Min; Liu, Xiaowen; Hu, Shunlin; Liu, Xiufan

2017-11-30

H3 subtype avian influenza virus (AIV) poses a great threat to public health, and so investigating its epidemiology is of great importance. A novel reassortant H3N2 AIV strain was isolated from a live poultry market in eastern China. The strain's genes originated from H1N1, H3, and H7 AIVs. Thus, the genome information of the H3N2 isolate will help to investigate further the epidemiology of H3 subtype AIVs in China. Copyright © 2017 Sun et al.

Serological Evidence of Human Infection with Avian Influenza A H7virus in Egyptian Poultry Growers.

PubMed

Gomaa, Mokhtar R; Kandeil, Ahmed; Kayed, Ahmed S; Elabd, Mona A; Zaki, Shaimaa A; Abu Zeid, Dina; El Rifay, Amira S; Mousa, Adel A; Farag, Mohamed M; McKenzie, Pamela P; Webby, Richard J; Ali, Mohamed A; Kayali, Ghazi

2016-01-01

Avian influenza viruses circulate widely in birds, with occasional human infections. Poultry-exposed individuals are considered to be at high risk of infection with avian influenza viruses due to frequent exposure to poultry. Some avian H7 viruses have occasionally been found to infect humans. Seroprevalence of neutralizing antibodies against influenza A/H7N7 virus among poultry-exposed and unexposed individuals in Egypt were assessed during a three-years prospective cohort study. The seroprevalence of antibodies (titer, ≥80) among exposed individuals was 0%, 1.9%, and 2.1% annually while the seroprevalence among the control group remained 0% as measured by virus microneutralization assay. We then confirmed our results using western blot and immunofluorescence assays. Although human infection with H7 in Egypt has not been reported yet, our results suggested that Egyptian poultry growers are exposed to avian H7 viruses. These findings highlight the need for surveillance in the people exposed to poultry to monitor the risk of zoonotic transmission of avian influenza viruses.

A 4-year study of avian influenza virus prevalence and subtype diversity in ducks of Newfoundland, Canada.

PubMed

Huang, Yanyan; Wille, Michelle; Dobbin, Ashley; Robertson, Gregory J; Ryan, Pierre; Ojkic, Davor; Whitney, Hugh; Lang, Andrew S

2013-10-01

The island of Newfoundland, Canada, is at the eastern edge of North America and has migratory bird connections with the continental mainland as well as across the North Atlantic Ocean. Here, we report a 4-year avian influenza virus (AIV) epidemiological study in ducks in the St. John's region of Newfoundland. The overall prevalence of AIV detection in ducks during this study was 7.2%, with American Black Ducks contributing the vast majority of the collected samples and the AIV positives. The juvenile ducks showed a significantly higher AIV detection rate (10.6%) compared with adults (3.4%). Seasonally, AIV prevalence rates were higher in the autumn (8.4%), but positives were still detected in the winter (4.6%). Preliminary serology tests showed a high incidence of previous AIV infection (20/38, 52.6%). A total of 43 viruses were characterized for their HA-NA or HA subtypes, which revealed a large diversity of AIV subtypes and little recurrence of subtypes from year to year. Investigation of the movement patterns of ducks in this region showed that it is a largely non-migratory duck population, which may contribute to the observed pattern of high AIV subtype turnover. Phylogenetic analysis of 4 H1N1 and one H5N4 AIVs showed these viruses were highly similar to other low pathogenic AIV sequences from waterfowl in North America and assigned all gene segments into American-avian clades. Notably, the H1N1 viruses, which were identified in consecutive years, possessed homologous genomes. Such detection of homologous AIV genomes across years is rare, but indicates the role of the environmental reservoir in viral perpetuation.

[Genetic evolution and substitution frequency of avian influenza virus HA gene in chicken H9N2 subtype in China in the last 20 years].

PubMed

Meng, Fang; Xu, Huaiying; Zhang, Wei; Huang, Dihai; Zhang, Zaihui; Liu, Xia; Chang, Weishan; Qin, Zhuoming

2016-01-04

Low pathogenic avian influenza (LPAI) H9N2 subtype virus has been prevalent in domestic poultry in China over two decades. This study was to determine the genetic evolution trend of H9N2 avian influenza virus (AIV) under immune pressure of vaccine. H9 HA sequences of 40 isolates from the present study and 136 pandemic strains and 7 classical strains from China downloaded from GenBank, were genetically analyzed to determine evolution, molecular characteristic, and mutation frequency. Phylogenetic trees analysis suggested that H9N2 subtypes AIV could be clustered into 5 distinct lineages: G1-like, BJ94-like, Y280-like, S2-like and Americans lineages. Most H9N2 isolates in 2005-2014 belonged to S2-like sub-genotype, suggesting that this genotype was the dominate isolates in China. Further more, comparison based on the amino acid sequence showed that different lineages have their distinct characteristics, and significant accumulations of amino acid variation were also found. In addition, in comparison with reference Ck/BJ/1/1994 HA gene, average annual substitution rates of H9N2 pandemic strain nucleotide and amino acid were 5.73 x 10⁻³ and 4.25 x 10⁻³ from 1994 to 2014, respectively. Substitution rate during 2011-2014 were 6.35 x 10⁻³ and 5.32 x 10⁻³, higher than that during the period of 2006-2010 (5.22 x 10⁻³ and 3.70 x 10⁻³) and even much higher than that during the 1999-2005 (0.74 x 10⁻³ and 0.50 x 10⁻³), when the vaccines were initially applied in the field. Overall, these data indicate that the mismatch between H9N2 vaccine strains and pandemic strains drives the virus to quickly mutate.

H9N2 low pathogenic avian influenza: Should we be afraid?

USDA-ARS?s Scientific Manuscript database

The H9N2 low pathogenic avian influenza (LPAI) is probably the most widespread avian influenza subtype in poultry around the world being endemic in a large part of Asia, the Middle East, Northern Africa, and in Germany. Currently, there is no standardized clade system to describe the antigenic vari...

Transmissibility of novel H7N9 and H9N2 avian influenza viruses between chickens and ferrets.

PubMed

Ku, Keun Bon; Park, Eun Hye; Yum, Jung; Kim, Heui Man; Kang, Young Myong; Kim, Jeong Cheol; Kim, Ji An; Kim, Hyun Soo; Seo, Sang Heui

2014-02-01

Previous studies have shown that the H7N9 avian influenza virus cannot be transmitted efficiently between ferrets via respiratory droplets. Here, we studied the infectivity of the H7N9 avian influenza virus in chickens and its transmissibility from infected to naïve chickens and ferrets. The H7N9 virus (A/Anhui/1/2013) replicated poorly in chickens and could not be transmitted efficiently from infected chickens to naïve chickens and ferrets. H7N9 virus was shed from chicken tracheae for only 2 days after infection and from chicken cloacae for only 1 day after infection, while the H9N2 avian influenza virus, which is endemic in chickens in many Asian countries, was shed from tracheae and cloacae for 8 days after infection. Taken together, our results suggest that chickens may be a poor agent of transmission for the H7N9 virus to other chickens and to mammals, including humans. Copyright © 2014 Elsevier Inc. All rights reserved.

The novel human influenza A(H7N9) virus is naturally adapted to efficient growth in human lung tissue.

PubMed

Knepper, Jessica; Schierhorn, Kristina L; Becher, Anne; Budt, Matthias; Tönnies, Mario; Bauer, Torsten T; Schneider, Paul; Neudecker, Jens; Rückert, Jens C; Gruber, Achim D; Suttorp, Norbert; Schweiger, Brunhilde; Hippenstiel, Stefan; Hocke, Andreas C; Wolff, Thorsten

2013-10-08

A novel influenza A virus (IAV) of the H7N9 subtype has been isolated from severely diseased patients with pneumonia and acute respiratory distress syndrome and, apparently, from healthy poultry in March 2013 in Eastern China. We evaluated replication, tropism, and cytokine induction of the A/Anhui/1/2013 (H7N9) virus isolated from a fatal human infection and two low-pathogenic avian H7 subtype viruses in a human lung organ culture system mimicking infection of the lower respiratory tract. The A(H7N9) patient isolate replicated similarly well as a seasonal IAV in explanted human lung tissue, whereas avian H7 subtype viruses propagated poorly. Interestingly, the avian H7 strains provoked a strong antiviral type I interferon (IFN-I) response, whereas the A(H7N9) virus induced only low IFN levels. Nevertheless, all viruses analyzed were detected predominantly in type II pneumocytes, indicating that the A(H7N9) virus does not differ in its cellular tropism from other avian or human influenza viruses. Tissue culture-based studies suggested that the low induction of the IFN-β promoter correlated with an efficient suppression by the viral NS1 protein. These findings demonstrate that the zoonotic A(H7N9) virus is unusually well adapted to efficient propagation in human alveolar tissue, which most likely contributes to the severity of lower respiratory tract disease seen in many patients. Humans are usually not infected by avian influenza A viruses (IAV), but this large group of viruses contributes to the emergence of human pandemic strains. Transmission of virulent avian IAV to humans is therefore an alarming event that requires assessment of the biology as well as pathogenic and pandemic potentials of the viruses in clinically relevant models. Here, we demonstrate that an early virus isolate from the recent A(H7N9) outbreak in Eastern China replicated as efficiently as human-adapted IAV in explanted human lung tissue, whereas avian H7 subtype viruses were unable to

Personal protective equipment and risk for avian influenza (H7N3).

PubMed

Morgan, Oliver; Kuhne, Mirjam; Nair, Pat; Verlander, Neville Q; Preece, Richard; McDougal, Marianne; Zambon, Maria; Reacher, Mark

2009-01-01

An outbreak of avian influenza (H7N3) among poultry resulted in laboratory-confirmed disease in 1 of 103 exposed persons. Incomplete use of personal protective equipment (PPE) was associated with conjunctivitis and influenza-like symptoms. Rigorous use of PPE by persons managing avian influenza outbreaks may reduce exposure to potentially hazardous infected poultry materials.

Personal Protective Equipment and Risk for Avian Influenza (H7N3)

PubMed Central

Kuhne, Mirjam; Nair, Pat; Verlander, Neville Q.; Preece, Richard; McDougal, Marianne; Zambon, Maria; Reacher, Mark

2009-01-01

An outbreak of avian influenza (H7N3) among poultry resulted in laboratory-confirmed disease in 1 of 103 exposed persons. Incomplete use of personal protective equipment (PPE) was associated with conjunctivitis and influenza-like symptoms. Rigorous use of PPE by persons managing avian influenza outbreaks may reduce exposure to potentially hazardous infected poultry materials. PMID:19116052

Unique Determinants of Neuraminidase Inhibitor Resistance among N3, N7, and N9 Avian Influenza Viruses.

PubMed

Song, Min-Suk; Marathe, Bindumadhav M; Kumar, Gyanendra; Wong, Sook-San; Rubrum, Adam; Zanin, Mark; Choi, Young-Ki; Webster, Robert G; Govorkova, Elena A; Webby, Richard J

2015-11-01

Human infections with avian influenza viruses are a serious public health concern. The neuraminidase (NA) inhibitors (NAIs) are the frontline anti-influenza drugs and are the major option for treatment of newly emerging influenza. Therefore, it is essential to identify the molecular markers of NAI resistance among specific NA subtypes of avian influenza viruses to help guide clinical management. NAI-resistant substitutions in NA subtypes other than N1 and N2 have been poorly studied. Here, we identified NA amino acid substitutions associated with NAI resistance among influenza viruses of N3, N7, and N9 subtypes which have been associated with zoonotic transmission. We applied random mutagenesis and generated recombinant influenza viruses carrying single or double NA substitution(s) with seven internal genes from A/Puerto Rico/8/1934 (H1N1) virus. In a fluorescence-based NA inhibition assay, we identified three categories of NA substitutions associated with reduced inhibition by NAIs (oseltamivir, zanamivir, and peramivir): (i) novel subtype-specific substitutions in or near the enzyme catalytic site (R152W, A246T, and D293N, N2 numbering), (ii) subtype-independent substitutions (E119G/V and/or D and R292K), and (iii) substitutions previously reported in other subtypes (Q136K, I222M, and E276D). Our data show that although some markers of resistance are present across NA subtypes, other subtype-specific markers can only be determined empirically. The number of humans infected with avian influenza viruses is increasing, raising concerns of the emergence of avian influenza viruses resistant to neuraminidase (NA) inhibitors (NAIs). Since most studies have focused on NAI-resistance in human influenza viruses, we investigated the molecular changes in NA that could confer NAI resistance in avian viruses grown in immortalized monolayer cells, especially those of the N3, N7, and N9 subtypes, which have caused human infections. We identified not only numerous NAI

Avian Influenza A(H5N1) Virus in Egypt.

PubMed

Kayali, Ghazi; Kandeil, Ahmed; El-Shesheny, Rabeh; Kayed, Ahmed S; Maatouq, Asmaa M; Cai, Zhipeng; McKenzie, Pamela P; Webby, Richard J; El Refaey, Samir; Kandeel, Amr; Ali, Mohamed A

2016-03-01

In Egypt, avian influenza A subtype H5N1 and H9N2 viruses are enzootic in poultry. The control plan devised by veterinary authorities in Egypt to prevent infections in poultry focused mainly on vaccination and ultimately failed. Recently, widespread H5N1 infections in poultry and a substantial increase in the number of human cases of H5N1 infection were observed. We summarize surveillance data from 2009 through 2014 and show that avian influenza viruses are established in poultry in Egypt and are continuously evolving genetically and antigenically. We also discuss the epidemiology of human infection with avian influenza in Egypt and describe how the true burden of disease is underestimated. We discuss the failures of relying on vaccinating poultry as the sole intervention tool. We conclude by highlighting the key components that need to be included in a new strategy to control avian influenza infections in poultry and humans in Egypt.

Avian Influenza A(H5N1) Virus in Egypt

PubMed Central

Kandeil, Ahmed; El-Shesheny, Rabeh; Kayed, Ahmed S.; Maatouq, Asmaa M.; Cai, Zhipeng; McKenzie, Pamela P.; Webby, Richard J.; El Refaey, Samir; Kandeel, Amr; Ali, Mohamed A.

2016-01-01

In Egypt, avian influenza A subtype H5N1 and H9N2 viruses are enzootic in poultry. The control plan devised by veterinary authorities in Egypt to prevent infections in poultry focused mainly on vaccination and ultimately failed. Recently, widespread H5N1 infections in poultry and a substantial increase in the number of human cases of H5N1 infection were observed. We summarize surveillance data from 2009 through 2014 and show that avian influenza viruses are established in poultry in Egypt and are continuously evolving genetically and antigenically. We also discuss the epidemiology of human infection with avian influenza in Egypt and describe how the true burden of disease is underestimated. We discuss the failures of relying on vaccinating poultry as the sole intervention tool. We conclude by highlighting the key components that need to be included in a new strategy to control avian influenza infections in poultry and humans in Egypt. PMID:26886164

Protection of poultry against the 2012 Mexican H7N3 highly pathogenic avian influenza virus with inactivated H7 avian influenza vaccines

USDA-ARS?s Scientific Manuscript database

In June of 2012, an outbreak of highly pathogenic avian influenza (HPAI) H7N3 was reported poultry in Jalisco, Mexico. Since that time the virus has spread to the surrounding States of Guanajuato and Aguascalientes and new outbreaks continue to be reported. To date more than 25 million birds have di...

China is closely monitoring an increase in infection with avian influenza A (H7N9) virus.

PubMed

Tang, Qi; Shao, Meiying; Xu, Lingzhong

2017-03-22

The fifth outbreak of human infection with avian influenza A (H7N9) virus has struck far and wide in China. The number of cases of infection with the avian influenza A (H7N9) suddenly increased in 2013-2014, but the number of cases reported this winter has exceeded the number reported in all previous seasons. Given this situation, the National Health and Family Planning Commission issued updated Chinese guidelines (2017 version) on diagnosis and treatment of infection with the avian influenza A (H7N9) virus on January 24, 2017. In addition, the Chinese Government closed many live poultry markets in urban and rural areas in a number of provinces and the Government has taken proactive measures to surveil, respond to, and prevent potential pandemics involving the avian influenza A (H7N9) virus.

Rapid detection of avian influenza virus a and subtype H5N1 by single step multiplex reverse transcription-polymerase chain reaction.

PubMed

Wei, Hui-Ling; Bai, Gui-Rong; Mweene, Aaron S; Zhou, Ying-Chun; Cong, Yan-Long; Pu, Juan; Wang, Shuai; Kida, Hiroshi; Liu, Jin-Hua

2006-06-01

Outbreaks of H5N1 highly pathogenic avian influenza (HPAI) virus caused great economic losses to the poultry industry and resulted in human deaths in Thailand and Viet Nam in 2004. Rapid typing and subtyping of H5N1 viruses, especially from clinical specimens, are desirable for taking prompt control measures to prevent the spread of the disease. Here, we developed a set of oligonucleotide primers able to detect, type and subtype H5 and N1 influenza viruses in a single step multiplex reverse transcription-polymerase chain reaction (RT-PCR). RNA was extracted from allantoic fluid or from specimens with guanidinium isothiocyanate reagent. Reverse transcription and PCR were carried out with a mixture of primers specific for influenza viruses of type A, subtype H5 and N1 in a single reaction system under identical conditions. The amplified DNA fragments were analyzed by agarose gel electrophoresis. All the H5N1 viruses tested in the study and the experimental specimens presented three specific bands by the method established here. The results presented here suggest that the method described below is rapid and specific and, therefore, could be valuable in the rapid detection of H5N1 influenza viruses in clinics.

The Genomic Contributions of Avian H1N1 Influenza A Viruses to the Evolution of Mammalian Strains

PubMed Central

Wu, Gang; Zhang, Jinghui; Webster, Robert G.

2015-01-01

Among the influenza A viruses (IAVs) in wild aquatic birds, only H1, H2, and H3 subtypes have caused epidemics in humans. H1N1 viruses of avian origin have also caused 3 of 5 pandemics. To understand the reappearance of H1N1 in the context of pandemic emergence, we investigated whether avian H1N1 IAVs have contributed to the evolution of human, swine, and 2009 pandemic H1N1 IAVs. On the basis of phylogenetic analysis, we concluded that the polymerase gene segments (especially PB2 and PA) circulating in North American avian H1N1 IAVs have been reintroduced to swine multiple times, resulting in different lineages that led to the emergence of the 2009 pandemic H1N1 IAVs. Moreover, the similar topologies of hemagglutinin and nucleoprotein and neuraminidase and matrix gene segments suggest that each surface glycoprotein coevolved with an internal gene segment within the H1N1 subtype. The genotype of avian H1N1 IAVs of Charadriiformes origin isolated in 2009 differs from that of avian H1N1 IAVs of Anseriformes origin. When the antigenic sites in the hemagglutinin of all 31 North American avian H1N1 IAVs were considered, 60%-80% of the amino acids at the antigenic sites were identical to those in 1918 and/or 2009 pandemic H1N1 viruses. Thus, although the pathogenicity of avian H1N1 IAVs could not be inferred from the phylogeny due to the small dataset, the evolutionary process within the H1N1 IAV subtype suggests that the circulation of H1N1 IAVs in wild birds poses a continuous threat for future influenza pandemics in humans. PMID:26208281

Transient expression of hemagglutinin antigen from low pathogenic avian influenza A (H7N7) in Nicotiana benthamiana.

PubMed

Kanagarajan, Selvaraju; Tolf, Conny; Lundgren, Anneli; Waldenström, Jonas; Brodelius, Peter E

2012-01-01

The influenza A virus is of global concern for the poultry industry, especially the H5 and H7 subtypes as they have the potential to become highly pathogenic for poultry. In this study, the hemagglutinin (HA) of a low pathogenic avian influenza virus of the H7N7 subtype isolated from a Swedish mallard Anas platyrhynchos was sequenced, characterized and transiently expressed in Nicotiana benthamiana. Recently, plant expression systems have gained interest as an alternative for the production of vaccine antigens. To examine the possibility of expressing the HA protein in N. benthamiana, a cDNA fragment encoding the HA gene was synthesized de novo, modified with a Kozak sequence, a PR1a signal peptide, a C-terminal hexahistidine (6×His) tag, and an endoplasmic retention signal (SEKDEL). The construct was cloned into a Cowpea mosaic virus (CPMV)-based vector (pEAQ-HT) and the resulting pEAQ-HT-HA plasmid, along with a vector (pJL3:p19) containing the viral gene-silencing suppressor p19 from Tomato bushy stunt virus, was agro-infiltrated into N. benthamiana. The highest gene expression of recombinant plant-produced, uncleaved HA (rHA0), as measured by quantitative real-time PCR was detected at 6 days post infiltration (dpi). Guided by the gene expression profile, rHA0 protein was extracted at 6 dpi and subsequently purified utilizing the 6×His tag and immobilized metal ion adsorption chromatography. The yield was 0.2 g purified protein per kg fresh weight of leaves. Further molecular characterizations showed that the purified rHA0 protein was N-glycosylated and its identity confirmed by liquid chromatography-tandem mass spectrometry. In addition, the purified rHA0 exhibited hemagglutination and hemagglutination inhibition activity indicating that the rHA0 shares structural and functional properties with native HA protein of H7 influenza virus. Our results indicate that rHA0 maintained its native antigenicity and specificity, providing a good source of vaccine antigen

Replication and pathogenic potential of influenza A virus subtypes H3, H7, and H15 from free-range ducks in Bangladesh in mammals.

PubMed

El-Shesheny, Rabeh; Feeroz, Mohammed M; Krauss, Scott; Vogel, Peter; McKenzie, Pamela; Webby, Richard J; Webster, Robert G

2018-04-25

Surveillance of wild aquatic birds and free-range domestic ducks in the Tanguar Haor wetlands in Bangladesh has identified influenza virus subtypes H3N6, H7N1, H7N5, H7N9, and H15N9. Molecular characterization of these viruses indicates their contribution to the genesis of new genotypes of H5N1 influenza viruses from clade 2.3.2.1a that are dominant in poultry markets in Bangladesh as well as to the genesis of the highly pathogenic H5N8 virus currently causing disease outbreaks in domestic poultry in Europe and the Middle East. Therefore, we studied the antigenicity, replication, and pathogenicity of influenza viruses isolated from Tanguar Haor in the DBA/2J mouse model. All viruses replicated in the lung without prior mammalian adaptation, and H7N1 and H7N9 viruses caused 100% and 60% mortality, respectively. H7N5 viruses replicated only in the lungs, whereas H7N1 and H7N9 viruses also replicated in the heart, liver, and brain. Replication and transmission studies in mallard ducks showed that H7N1 and H7N9 viruses replicated in ducks without clinical signs of disease and shed at high titers from the cloaca of infected and contact ducks, which could facilitate virus transmission and spread. Our results indicate that H7 avian influenza viruses from free-range ducks can replicate in mammals, cause severe disease, and be efficiently transmitted to contact ducks. Our study highlights the role of free-range ducks in the spread of influenza viruses to other species in live poultry markets and the potential for these viruses to infect and cause disease in mammals.

Detecting Spread of Avian Influenza A(H7N9) Virus Beyond China

PubMed Central

Havers, Fiona; Iuliano, A. Danielle; Davis, C. Todd; Sar, Borann; Sovann, Ly; Chin, Savuth; Corwin, Andrew L.; Vongphrachanh, Phengta; Douangngeun, Bounlom; Lindblade, Kim A.; Chittaganpitch, Malinee; Kaewthong, Viriya; Kile, James C.; Nguyen, Hien T.; Pham, Dong V.; Donis, Ruben O.; Widdowson, Marc-Alain

2015-01-01

During February 2013–March 2015, a total of 602 human cases of low pathogenic avian influenza A(H7N9) were reported; no autochthonous cases were reported outside mainland China. In contrast, since highly pathogenic avian influenza A(H5N1) reemerged during 2003 in China, 784 human cases in 16 countries and poultry outbreaks in 53 countries have been reported. Whether the absence of reported A(H7N9) outside mainland China represents lack of spread or lack of detection remains unclear. We compared epidemiologic and virologic features of A(H5N1) and A(H7N9) and used human and animal influenza surveillance data collected during April 2013–May 2014 from 4 Southeast Asia countries to assess the likelihood that A(H7N9) would have gone undetected during 2014. Surveillance in Vietnam and Cambodia detected human A(H5N1) cases; no A(H7N9) cases were detected in humans or poultry in Southeast Asia. Although we cannot rule out the possible spread of A(H7N9), substantial spread causing severe disease in humans is unlikely. PMID:25897654

Role for migratory wild birds in the global spread of avian influenza H5N8

USGS Publications Warehouse

,; Ip, Hon S.

2016-01-01

Avian influenza viruses affect both poultry production and public health. A subtype H5N8 (clade 2.3.4.4) virus, following an outbreak in poultry in South Korea in January 2014, rapidly spread worldwide in 2014–2015. Our analysis of H5N8 viral sequences, epidemiological investigations, waterfowl migration, and poultry trade showed that long-distance migratory birds can play a major role in the global spread of avian influenza viruses. Further, we found that the hemagglutinin of clade 2.3.4.4 virus was remarkably promiscuous, creating reassortants with multiple neuraminidase subtypes. Improving our understanding of the circumpolar circulation of avian influenza viruses in migratory waterfowl will help to provide early warning of threats from avian influenza to poultry, and potentially human, health.

Analysis of antigen conservation and inactivation of gamma-irradiated avian influenza virus subtype H9N2.

PubMed

Salehi, Bahareh; Motamedi-Sedeh, Farahnaz; Madadgar, Omid; Khalili, Iraj; Ghalyan Chi Langroudi, Arash; Unger, Hermann; Wijewardana, Viskam

2018-06-01

Avian influenza (AI) A subtype H9N2 virus belongs to Orthomyxoviridae family and causes low-pathogenic disease AI. The use of gamma-irradiated viral antigens has been developed in the production of effective vaccines. In this research, LPAIV H9N2 strain, A/Chicken/IRN/Ghazvin/2001, was multiplied on SPF eggs and irradiated by a Nordian gamma cell instrument. Irradiated and non-irradiated AI virus (AIV) samples were titrated by EID50 method and hemagglutinin (HA) antigen was analyzed by HA test as the WHO pattern method. Infectivity of irradiated virus was determined by egg inoculation method during four blind cultures. The results showed that after increasing the dose of gamma radiation, virus titer gradually decreased. D 10 value and optimum dose for complete virus inactivation were calculated by dose/response curve, 3.36 and 29.52 kGy, respectively. In addition, HA antigenicity of gamma-irradiated virus samples from 0 to 30 kGy was not changed. The results of safety test for gamma-irradiated AIV samples showed complete inactivation with gamma ray doses 30 and 35 kGy, without any multiplication on eggs after four blind cultures. According to the results of HA antigen assay and safety test, the gamma-irradiated and complete inactivated AIV subtype H9N2 is a good candidate as an inactivated immunogenic agent for poultry vaccination.

(Highly pathogenic) avian influenza as a zoonotic agent.

PubMed

Kalthoff, Donata; Globig, Anja; Beer, Martin

2010-01-27

Zoonotic agents challenging the world every year afresh are influenza A viruses. In the past, human pandemics caused by influenza A viruses had been occurring periodically. Wild aquatic birds are carriers of the full variety of influenza virus A subtypes, and thus, most probably constitute the natural reservoir of all influenza A viruses. Whereas avian influenza viruses in their natural avian reservoir are generally of low pathogenicity (LPAIV), some have gained virulence by mutation after transmission and adaptation to susceptible gallinaceous poultry. Those so-called highly pathogenic avian influenza viruses (HPAIV) then cause mass die-offs in susceptible birds and lead to tremendous economical losses when poultry is affected. Besides a number of avian influenza virus subtypes that have sporadically infected mammals, the HPAIV H5N1 Asia shows strong zoonotic characteristics and it was transmitted from birds to different mammalian species including humans. Theoretically, pandemic viruses might derive directly from avian influenza viruses or arise after genetic reassortment between viruses of avian and mammalian origin. So far, HPAIV H5N1 already meets two conditions for a pandemic virus: as a new subtype it has been hitherto unseen in the human population and it has infected at least 438 people, and caused severe illness and high lethality in 262 humans to date (August 2009). The acquisition of efficient human-to-human transmission would complete the emergence of a new pandemic virus. Therefore, fighting H5N1 at its source is the prerequisite to reduce pandemic risks posed by this virus. Other influenza viruses regarded as pandemic candidates derive from subtypes H2, H7, and H9 all of which have infected humans in the past. Here, we will give a comprehensive overview on avian influenza viruses in concern to their zoonotic potential. Copyright 2009 Elsevier B.V. All rights reserved.

Highly pathogenic avian influenza A(H7N9) virus, Tennessee, USA, March 2017

USDA-ARS?s Scientific Manuscript database

In March 2017, highly pathogenic avian influenza A(H7N9) was detected at 2 poultry farms in Tennessee, USA. Surveillance data and genetic analyses indicated multiple introductions of low pathogenicity avian influenza virus before mutation to high pathogenicity and interfarm transmission. Poultry sur...

Avian influenza virus infections in humans.

PubMed

Wong, Samson S Y; Yuen, Kwok-Yung

2006-01-01

Seroepidemiologic and virologic studies since 1889 suggested that human influenza pandemics were caused by H1, H2, and H3 subtypes of influenza A viruses. If not for the 1997 avian A/H5N1 outbreak in Hong Kong of China, subtype H2 is the likely candidate for the next pandemic. However, unlike previous poultry outbreaks of highly pathogenic avian influenza due to H5 that were controlled by depopulation with or without vaccination, the presently circulating A/H5N1 genotype Z virus has since been spreading from Southern China to other parts of the world. Migratory birds and, less likely, bird trafficking are believed to be globalizing the avian influenza A/H5N1 epidemic in poultry. More than 200 human cases of avian influenza virus infection due to A/H5, A/H7, and A/H9 subtypes mainly as a result of poultry-to-human transmission have been reported with a > 50% case fatality rate for A/H5N1 infections. A mutant or reassortant virus capable of efficient human-to-human transmission could trigger another influenza pandemic. The recent isolation of this virus in extrapulmonary sites of human diseases suggests that the high fatality of this infection may be more than just the result of a cytokine storm triggered by the pulmonary disease. The emergence of resistance to adamantanes (amantadine and rimantadine) and recently oseltamivir while H5N1 vaccines are still at the developmental stage of phase I clinical trial are causes for grave concern. Moreover, the to-be pandemic strain may have little cross immunogenicity to the presently tested vaccine strain. The relative importance and usefulness of airborne, droplet, or contact precautions in infection control are still uncertain. Laboratory-acquired avian influenza H7N7 has been reported, and the laboratory strains of human influenza H2N2 could also be the cause of another pandemic. The control of this impending disaster requires more research in addition to national and international preparedness at various levels. The

Role for migratory wild birds in the global spread of avian influenza H5N8.

PubMed

2016-10-14

Avian influenza viruses affect both poultry production and public health. A subtype H5N8 (clade 2.3.4.4) virus, following an outbreak in poultry in South Korea in January 2014, rapidly spread worldwide in 2014-2015. Our analysis of H5N8 viral sequences, epidemiological investigations, waterfowl migration, and poultry trade showed that long-distance migratory birds can play a major role in the global spread of avian influenza viruses. Further, we found that the hemagglutinin of clade 2.3.4.4 virus was remarkably promiscuous, creating reassortants with multiple neuraminidase subtypes. Improving our understanding of the circumpolar circulation of avian influenza viruses in migratory waterfowl will help to provide early warning of threats from avian influenza to poultry, and potentially human, health. Copyright © 2016, American Association for the Advancement of Science.

PB2-588 V promotes the mammalian adaptation of H10N8, H7N9 and H9N2 avian influenza viruses

PubMed Central

Xiao, Chencheng; Ma, Wenjun; Sun, Na; Huang, Lihong; Li, Yaling; Zeng, Zhaoyong; Wen, Yijun; Zhang, Zaoyue; Li, Huanan; Li, Qian; Yu, Yuandi; Zheng, Yi; Liu, Shukai; Hu, Pingsheng; Zhang, Xu; Ning, Zhangyong; Qi, Wenbao; Liao, Ming

2016-01-01

Human infections with avian influenza H7N9 or H10N8 viruses have been reported in China, raising concerns that they might cause human epidemics and pandemics. However, how these viruses adapt to mammalian hosts is unclear. Here we show that besides the commonly recognized viral polymerase subunit PB2 residue 627 K, other residues including 87E, 292 V, 340 K, 588 V, 648 V, and 676 M in PB2 also play critical roles in mammalian adaptation of the H10N8 virus. The avian-origin H10N8, H7N9, and H9N2 viruses harboring PB2-588 V exhibited higher polymerase activity, more efficient replication in mammalian and avian cells, and higher virulence in mice when compared to viruses with PB2-588 A. Analyses of available PB2 sequences showed that the proportion of avian H9N2 or human H7N9 influenza isolates bearing PB2-588 V has increased significantly since 2013. Taken together, our results suggest that the substitution PB2-A588V may be a new strategy for an avian influenza virus to adapt mammalian hosts. PMID:26782141

Characterization of Clade 7.2 H5 Avian Influenza Viruses That Continue To Circulate in Chickens in China

PubMed Central

Liu, Liling; Zeng, Xianying; Chen, Pucheng; Deng, Guohua; Li, Yanbing; Shi, Jianzhong; Gu, Chunyang; Kong, Huihui; Suzuki, Yasuo; Jiang, Yongping; Tian, Guobin

2016-01-01

ABSTRACT The H5N1 avian influenza viruses emerged in Southeast Asia in the late 20th century and have evolved into multiple phylogenetic clades based on their hemagglutinin (HA)-encoding genes. The clade 7.2 viruses were first detected in chickens in northern China in 2006, and vaccines specifically targeted to the clade were developed and have been used in poultry in China since 2006. During routine surveillance and disease diagnosis, we isolated seven H5 viruses between 2011 and 2014 that bear the clade 7.2 HA genes. Here, we performed extensive studies to understand how the clade 7.2 H5 viruses have evolved in chickens in China. Full genome sequence analysis revealed that the seven viruses formed two subtypes (four H5N1 viruses and three H5N2 viruses) and four genotypes by deriving genes from other influenza viruses. All of the viruses had antigenically drifted from the clade 7.2 viruses that were isolated in 2006. Pathogenicity studies of four viruses, one from each genotype, revealed that all of the viruses are highly pathogenic in chickens, but none of them could replicate in ducks. The four viruses exclusively bound to avian-type receptors and replicated only in the turbinates and/or lungs of mice; none of them were lethal to mice at a dosage of 106 50% egg infective doses (EID50). Our study indicates that although the clade 7.2 viruses have not been eradicated from poultry through vaccination, they have not become more dangerous to other animals (e.g., ducks and mice) and humans. IMPORTANCE Animal influenza viruses can acquire the ability to infect and kill humans. The H5N1 viruses have been a concern in recent decades because of their clear pandemic potential. We sorted H5N1 influenza viruses into different phylogenetic clades based on their HA genes. The clade 7.2 viruses were detected in chickens in several provinces of northern China in 2006. Vaccines for these viruses were subsequently developed and have been used ever since to control infection of

Characterization of Clade 7.2 H5 Avian Influenza Viruses That Continue To Circulate in Chickens in China.

PubMed

Liu, Liling; Zeng, Xianying; Chen, Pucheng; Deng, Guohua; Li, Yanbing; Shi, Jianzhong; Gu, Chunyang; Kong, Huihui; Suzuki, Yasuo; Jiang, Yongping; Tian, Guobin; Chen, Hualan

2016-11-01

The H5N1 avian influenza viruses emerged in Southeast Asia in the late 20th century and have evolved into multiple phylogenetic clades based on their hemagglutinin (HA)-encoding genes. The clade 7.2 viruses were first detected in chickens in northern China in 2006, and vaccines specifically targeted to the clade were developed and have been used in poultry in China since 2006. During routine surveillance and disease diagnosis, we isolated seven H5 viruses between 2011 and 2014 that bear the clade 7.2 HA genes. Here, we performed extensive studies to understand how the clade 7.2 H5 viruses have evolved in chickens in China. Full genome sequence analysis revealed that the seven viruses formed two subtypes (four H5N1 viruses and three H5N2 viruses) and four genotypes by deriving genes from other influenza viruses. All of the viruses had antigenically drifted from the clade 7.2 viruses that were isolated in 2006. Pathogenicity studies of four viruses, one from each genotype, revealed that all of the viruses are highly pathogenic in chickens, but none of them could replicate in ducks. The four viruses exclusively bound to avian-type receptors and replicated only in the turbinates and/or lungs of mice; none of them were lethal to mice at a dosage of 10 6 50% egg infective doses (EID 50 ). Our study indicates that although the clade 7.2 viruses have not been eradicated from poultry through vaccination, they have not become more dangerous to other animals (e.g., ducks and mice) and humans. Animal influenza viruses can acquire the ability to infect and kill humans. The H5N1 viruses have been a concern in recent decades because of their clear pandemic potential. We sorted H5N1 influenza viruses into different phylogenetic clades based on their HA genes. The clade 7.2 viruses were detected in chickens in several provinces of northern China in 2006. Vaccines for these viruses were subsequently developed and have been used ever since to control infection of poultry. Here, we

Isolation of herpesvirus and Newcastle disease virus from White Storks (Ciconia ciconia) maintained at four rehabilitation centres in northern Germany during 1983 to 2001 and failure to detect antibodies against avian influenza A viruses of subtypes H5 and H7 in these birds.

PubMed

Kaleta, Erhard F; Kummerfeld, Norbert

2012-01-01

Herpesvirus isolations from peripheral white blood cells of 253 White Storks (Ciconia ciconia) were obtained during a long-term study (1983 to 2001). The storks lived for a few months to 20 years at four rehabilitation centres. Isolates were obtained from 83 of 253 storks. This herpesvirus is indigenous for storks and unrelated to any other avian herpesvirus. Significantly more herpesvirus isolates were obtained during spring than in autumn samplings. The intervals between the first and last virus isolation ranged from 1 to 15 years. Herpesvirus isolates were simultaneously obtained from white blood cells and from pharyngeal swabs of four of 34 storks but not from cloacal swabs. Neutralizing antibodies to stork herpesvirus were detected in 178 of 191 examined blood plasma samples. Neutralizing antibodies against stork herpesvirus did not correlate with herpesvirus viraemia. The results further substantiate the persistence of herpesvirus in White Storks and underline the previously unrecorded long periods of virus and antibody presence. Virulent avian paramyxovirus type 1 (APMV-1; Newcastle disease virus) was isolated from white blood cells during 1992 and 1993 from four healthy migrating storks, and possessed virulence markers on the cleavage site of the H and F genes. These properties resemble the NE type of APMV-1. Haemagglutination inhibition antibodies against APMV-1 were detected in 16 of 191 blood plasma samples. Avian influenza A virus was not isolated and antibodies against subtypes H5 and H7 were not detected.

Influenza virus A (H10N7) in chickens and poultry abattoir workers, Australia.

PubMed

Arzey, George G; Kirkland, Peter D; Arzey, K Edla; Frost, Melinda; Maywood, Patrick; Conaty, Stephen; Hurt, Aeron C; Deng, Yi-Mo; Iannello, Pina; Barr, Ian; Dwyer, Dominic E; Ratnamohan, Mala; McPhie, Kenneth; Selleck, Paul

2012-05-01

In March 2010, an outbreak of low pathogenicity avian influenza A (H10N7) occurred on a chicken farm in Australia. After processing clinically normal birds from the farm, 7 abattoir workers reported conjunctivitis and minor upper respiratory tract symptoms. Influenza virus A subtype H10 infection was detected in 2 workers.

The pandemic potential of avian influenza A(H7N9) virus: a review.

PubMed

Tanner, W D; Toth, D J A; Gundlapalli, A V

2015-12-01

In March 2013 the first cases of human avian influenza A(H7N9) were reported to the World Health Organization. Since that time, over 650 cases have been reported. Infections are associated with considerable morbidity and mortality, particularly within certain demographic groups. This rapid increase in cases over a brief time period is alarming and has raised concerns about the pandemic potential of the H7N9 virus. Three major factors influence the pandemic potential of an influenza virus: (1) its ability to cause human disease, (2) the immunity of the population to the virus, and (3) the transmission potential of the virus. This paper reviews what is currently known about each of these factors with respect to avian influenza A(H7N9). Currently, sustained human-to-human transmission of H7N9 has not been reported; however, population immunity to the virus is considered very low, and the virus has significant ability to cause human disease. Several statistical and geographical modelling studies have estimated and predicted the spread of the H7N9 virus in humans and avian species, and some have identified potential risk factors associated with disease transmission. Additionally, assessment tools have been developed to evaluate the pandemic potential of H7N9 and other influenza viruses. These tools could also hypothetically be used to monitor changes in the pandemic potential of a particular virus over time.

Avian influenza viruses (AIVs) H9N2 are in the course of reassorting into novel AIVs.

PubMed

Chang, Hui-Ping; Peng, Li; Chen, Liang; Jiang, Lu-Fang; Zhang, Zhi-Jie; Xiong, Cheng-Long; Zhao, Gen-Ming; Chen, Yue; Jiang, Qing-Wu

2018-05-01

In 2013, two episodes of influenza emerged in China and caused worldwide concern. A new H7N9 avian influenza virus (AIV) first appeared in China on February 19, 2013. By August 31, 2013, the virus had spread to ten provinces and two metropolitan cities. Of 134 patients with H7N9 influenza, 45 died. From then on, epidemics emerged sporadically in China and resulted in several victims. On November 30, 2013, a 73-year-old woman presented with an influenza-like illness. She developed multiple organ failure and died 9 d after the onset of disease. A novel reassortant AIV, H10N8, was isolated from a tracheal aspirate specimen that was obtained from the patient 7 d after onset. This case was the first human case of influenza A subtype H10N8. On 4 February, 2014, another death due to H10N8 avian influenza was reported in Jiangxi Province, China.

Transcriptional analysis of the innate immune response of ducks to different species-of-origin low pathogenic H7 avian influenza viruses.

PubMed

Maughan, Michele N; Dougherty, Lorna S; Preskenis, Lauren A; Ladman, Brian S; Gelb, Jack; Spackman, Erica V; Keeler, Calvin L

2013-03-23

Wild waterfowl, including ducks, represent the classic reservoir for low pathogenicity avian influenza (LPAI) viruses and play a major role in the worldwide dissemination of AIV. AIVs belonging to the hemagglutinin (H) 7 subtype are of epidemiological and economic importance due to their potential to mutate into a highly pathogenic form of the virus. Thus far, however, relatively little work has been conducted on elucidating the host-pathogen interactions of ducks and H7 LPAIVs. In the current study, three H7 LPAIVs isolated from either chicken, duck, or turkey avian species were evaluated for their comparative effect on the transcriptional innate immune response of ducks. Three H7 LPAIV isolates, chicken-origin (A/chicken/Maryland/MinhMa/2004), duck-origin (A/pintail/Minnesota/423/1999), and turkey-origin (A/turkey/Virginia/SEP-67/2002) were used to infect Pekin ducks. At 3 days post-infection, RNA from spleen tissue was used for transcriptional analysis using the Avian Innate Immune Microarray (AIIM) and quantitative real-time RT-PCR (qRT-PCR). Microarray analysis revealed that a core set of 61 genes was differentially regulated in response to all three LPAIVs. Furthermore, we observed 101, 135, and 628 differentially expressed genes unique to infection with the chicken-, duck-, or turkey-origin LPAIV isolates, respectively. qRT-PCR results revealed significant (p<0.05) induction of IL-1β, IL-2, and IFNγ transcription, with the greatest induction observed upon infection with the chicken-origin isolate. Several key innate immune pathways were activated in response to LPAIV infection including the toll-like receptor and RIG-I-like receptor pathways. Pekin ducks elicit a unique innate immune response to different species-of-origin H7 LPAIV isolates. However, twelve identifiable genes and their associated cell signaling pathways (RIG-I, NOD, TLR) are differentially expressed regardless of isolate origin. This core set of genes are critical to the duck immune

Preliminary Epidemiology of Human Infections with Highly Pathogenic Avian Influenza A(H7N9) Virus, China, 2017.

PubMed

Zhou, Lei; Tan, Yi; Kang, Min; Liu, Fuqiang; Ren, Ruiqi; Wang, Yali; Chen, Tao; Yang, Yiping; Li, Chao; Wu, Jie; Zhang, Hengjiao; Li, Dan; Greene, Carolyn M; Zhou, Suizan; Iuliano, A Danielle; Havers, Fiona; Ni, Daxin; Wang, Dayan; Feng, Zijian; Uyeki, Timothy M; Li, Qun

2017-08-01

We compared the characteristics of cases of highly pathogenic avian influenza (HPAI) and low pathogenic avian influenza (LPAI) A(H7N9) virus infections in China. HPAI A(H7N9) case-patients were more likely to have had exposure to sick and dead poultry in rural areas and were hospitalized earlier than were LPAI A(H7N9) case-patients.

Characterization of Low Pathogenic Avian Influenza Virus Subtype H9N2 Isolated from Free-Living Mynah Birds (Acridotheres tristis) in the Sultanate of Oman.

PubMed

Body, Mohammad H; Alrarawahi, Abdulmajeed H; Alhubsy, Saif S; Saravanan, Nirmala; Rajmony, Sunil; Mansoor, Muhammad Khalid

2015-06-01

A low pathogenic avian influenza virus was identified from free-living birds (mynah, Acridotheres tristis) of the starling family. Virus was isolated by inoculation of homogenized suspension from lung, tracheal, spleen, and cloacal swabs into the allantoic cavity of embryonated chicken eggs. Subtype of the isolate was characterized as H9N2 by hemagglutination inhibition test using monospecific chicken antisera to a wide range of influenza reference strain. Pathogenicity of the isolate was determined by intravenous pathogenicity index. The virus was reisolated from experimentally infected chicken. Additionally, the isolate was subjected to reverse transcriptase PCR using partial hemagglutinin (HA) gene-specific primers and yielded an amplicon of 487 bp. HA gene sequence analysis revealed 99% sequence homology among mynah and chicken isolates from Oman. On phylogenetic analysis, isolates from mynah (A/mynnah/Oman/AIVS6/2005) and chicken (A/chicken/Oman/AIVS3/2006; A/chicken/Oman/AIVS7/2006) clustered together tightly, indicating these free-flying birds may be a source of introduction of H9N2 subtype in poultry bird in Oman. Moreover, the HA gene of H9N2 isolates from Oman resembled those of viruses of the G1-like lineage and were very similar to those from United Arab Emirates.

Multiplex RT-PCR assay for differentiating European swine influenza virus subtypes H1N1, H1N2 and H3N2.

PubMed

Chiapponi, Chiara; Moreno, Ana; Barbieri, Ilaria; Merenda, Marianna; Foni, Emanuela

2012-09-01

In Europe, three major swine influenza viral (SIV) subtypes (H1N1, H1N2 and H3N2) have been isolated in pigs. Developing a test that is able to detect and identify the subtype of the circulating strain rapidly during an outbreak of respiratory disease in the pig population is of essential importance. This study describes two multiplex RT-PCRs which distinguish the haemagglutinin (HA) gene and the neuraminidase (NA) gene of the three major subtypes of SIV circulating in Europe. The HA PCR was able to identify the lineage (avian or human) of the HA of H1 subtypes. The analytical sensitivity of the test, considered to be unique, was assessed using three reference viruses. The detection limit corresponded to 1×10(-1) TCID(50)/200μl for avian-like H1N1, 1×10(0) TCID(50)/200μl for human-like H1N2 and 1×10(1) TCID(50)/200μl for H3N2 SIV. The multiplex RT-PCR was first carried out on a collection of 70 isolated viruses showing 100% specificity and then on clinical samples, from which viruses had previously been isolated, resulting in an 89% positive specificity of the viral subtype. Finally, the test was able to identify the viral subtype correctly in 56% of influenza A positive samples, from which SIV had not been isolated previously. It was also possible to identify mixed viral infections and the circulation of a reassortant strain before performing genomic studies. Copyright © 2012 Elsevier B.V. All rights reserved.

EVALUATION OF A COMMERCIAL COMPETITIVE ENZYME-LINKED IMMUNOSORBENT ASSAY FOR DETECTION OF AVIAN INFLUENZA VIRUS SUBTYPE H5 ANTIBODIES IN ZOO BIRDS.

PubMed

Jensen, Trine Hammer; Andersen, Jannie Holmegaard; Hjulsager, Charlotte Kristiane; Chriél, Mariann; Bertelsen, Mads Frost

2017-09-01

The hemagglutination inhibition (HI) test is the current gold standard for detecting antibodies to avian influenza virus (AIV). Enzyme-linked immunosorbent assays (ELISAs) have been explored for use in poultry and certain wild bird species because of high efficiency and lower cost. This study compared a commercial ELISA for detection of AIV subtype H5 antibodies with HI test of 572 serum samples from zoo birds. There was no significant difference between the results of the two tests when statistically compared by a McNemar χ 2 test (P = 0.86) and assessment of κ (κ = 0.87). With a specificity of 94.2% (95% confidence interval [CI], 0.92-0.97), a sensitivity of 93.9% (95% CI, 0.91-0.97), and an excellent correlation between the two tests, this ELISA can be recommended as an alternative to the HI test for preliminary screening of zoo bird sera for antibodies to AIV subtype H5.

Rapid Emergence of Highly Pathogenic Avian Influenza Subtypes from a Subtype H5N1 Hemagglutinin Variant.

PubMed

de Vries, Erik; Guo, Hongbo; Dai, Meiling; Rottier, Peter J M; van Kuppeveld, Frank J M; de Haan, Cornelis A M

2015-05-01

In 2014, novel highly pathogenic avian influenza A H5N2, H5N5, H5N6, and H5N8 viruses caused outbreaks in Asia, Europe, and North America. The H5 genes of these viruses form a monophyletic group that evolved from a clade 2.3.4 H5N1 variant. This rapid emergence of new H5Nx combinations is unprecedented in the H5N1 evolutionary history.

Susceptibility of wild passerines to subtype H5N1 highly pathogenic avian influenza viruses.

PubMed

Fujimoto, Yoshikazu; Usui, Tatsufumi; Ito, Hiroshi; Ono, Etsuro; Ito, Toshihiro

2015-01-01

Highly pathogenic avian influenza (HPAI) viruses of the H5N1 subtype have spread throughout many areas of Asia, Europe and Africa, and numerous cases of HPAI outbreaks in domestic and wild birds have been reported. Although recent studies suggest that the dissemination of H5N1 viruses is closely linked to the migration of wild birds, information on the potential for viral infection in species other than poultry and waterfowl is relatively limited. To investigate the susceptibility of terrestrial wild birds to infection with H5N1 HPAI viruses, common reed buntings (Emberiza schoeniclus), pale thrushes (Turdus pallidus) and brown-eared bulbuls (Hypsipetes amaurotis) were infected with A/mountain hawk-eagle/Kumamoto/1/07(H5N1) and A/whooper swan/Aomori/1/08(H5N1). The results showed that common reed buntings and brown-eared bulbuls were severely affected by both virus strains (100% mortality). While pale thrushes did not exhibit any clinical signs, seroconversion was confirmed. In common reed buntings, intraspecies-transmission of A/whooper swan/Aomori/1/08 to contact birds was also confirmed. The findings show that three passerine species; common reed buntings, brown-eared bulbuls and pale thrushes are susceptible to infection by H5N1 HPAI viruses, which emphasizes that continued surveillance of species other than waterfowl is crucial for effective monitoring of H5N1 HPAI virus outbreaks.

Avian influenza survey in migrating waterfowl in Sonora, Mexico.

PubMed

Montalvo-Corral, M; López-Robles, G; Hernández, J

2011-02-01

A two-year survey was carried out on the occurrence of avian influenza in migrating birds in two estuaries of the Mexican state of Sonora, which is located within the Pacific flyway. Cloacal and oropharyngeal swabs were collected from 1262 birds, including 20 aquatic bird species from the Moroncarit and Tobari estuaries in Sonora, Mexico. Samples were tested for type A influenza (M), H5 Eurasian and North American subtypes (H5EA and H5NA respectively) and the H7 North American subtype (H7NA). Gene detection was determined by one-step real-time reverse transcription polymerase chain reaction (RRT-PCR). The results revealed that neither the highly pathogenic avian influenza virus H5 of Eurasian lineage nor H7NA were detected. The overall prevalence of avian influenza type A (M-positive) in the sampled birds was 3.6% with the vast majority in dabbling ducks (Anas species). Samples from two birds, one from a Redhead (Aythya americana) and another from a Northern Shoveler (Anas clypeata), were positive for the low-pathogenic H5 avian influenza virus of North American lineage. These findings represented documented evidence of the occurrence of avian influenza in wintering birds in the Mexican wetlands. This type of study contributes to the understanding of how viruses spread to new regions of North America and highlights the importance of surveillance for the early detection and control of potentially pathogenic strains, which could affect animal and human health. © 2010 Blackwell Verlag GmbH.

Environmental Sampling for Avian Influenza A(H7N9) in Live-Poultry Markets in Guangdong, China

PubMed Central

Kang, Min; He, Jianfeng; Song, Tie; Rutherford, Shannon; Wu, Jie; Lin, Jinyan; Huang, Guofeng; Tan, Xiaohua; Zhong, Haojie

2015-01-01

Background To provide an increased understanding of avian influenza A(H7N9) activity in live-poultry market in space and time and hence improve H7N9 epidemic control, an ongoing environmental sampling program in multiple live-poultry markets across Guangdong, China was conducted during March 2013–June 2014. Methods A total of 625 live-poultry markets throughout 21 prefecture areas took part in the study. A total of 10 environmental sites in markets for sampling were identified to represent 4 different poultry-related activity areas. At least 10 environmental samples were collected from each market every month. The real time RT-PCR was performed to detect the avian influenza A(H7N9) virus. Field survey was conducted to investigate the sanitation status of live-poultry markets. Results There were 109 human infections with H7N9 avian influenza in Guangdong, of which 37 (34%) died. A total of 18741 environmental swabs were collected and subjected to real-time RT-PCR test, of which 905(4.83%) were found positive for H7N9 virus. There were 201 (32.16%) markets affected by H7N9 in 16 prefecture areas. The detection of H7N9 virus in markets spiked in winter months. 63.33% markets (38/60) had no physical segregation for poultry holding, slaughter or sale zones. Closing live-poultry market significantly decreased the H7N9 detection rate from 14.83% (112/755) to 1.67% (5/300). Conclusions This study indicates the importance of live-poultry market surveillance based on environmental sampling for H7N9 Avian Influenza control. Improving live-poultry market management and sanitation and changing consumer practices are critical to reduce the risk of H7N9 infection. PMID:25933138

Environmental Sampling for Avian Influenza A(H7N9) in Live-Poultry Markets in Guangdong, China.

PubMed

Kang, Min; He, Jianfeng; Song, Tie; Rutherford, Shannon; Wu, Jie; Lin, Jinyan; Huang, Guofeng; Tan, Xiaohua; Zhong, Haojie

2015-01-01

To provide an increased understanding of avian influenza A(H7N9) activity in live-poultry market in space and time and hence improve H7N9 epidemic control, an ongoing environmental sampling program in multiple live-poultry markets across Guangdong, China was conducted during March 2013-June 2014. A total of 625 live-poultry markets throughout 21 prefecture areas took part in the study. A total of 10 environmental sites in markets for sampling were identified to represent 4 different poultry-related activity areas. At least 10 environmental samples were collected from each market every month. The real time RT-PCR was performed to detect the avian influenza A(H7N9) virus. Field survey was conducted to investigate the sanitation status of live-poultry markets. There were 109 human infections with H7N9 avian influenza in Guangdong, of which 37 (34%) died. A total of 18741 environmental swabs were collected and subjected to real-time RT-PCR test, of which 905(4.83%) were found positive for H7N9 virus. There were 201 (32.16%) markets affected by H7N9 in 16 prefecture areas. The detection of H7N9 virus in markets spiked in winter months. 63.33% markets (38/60) had no physical segregation for poultry holding, slaughter or sale zones. Closing live-poultry market significantly decreased the H7N9 detection rate from 14.83% (112/755) to 1.67% (5/300). This study indicates the importance of live-poultry market surveillance based on environmental sampling for H7N9 Avian Influenza control. Improving live-poultry market management and sanitation and changing consumer practices are critical to reduce the risk of H7N9 infection.

Human Infection with Highly Pathogenic Avian Influenza A(H7N9) Virus, China

PubMed Central

Ke, Changwen; Mok, Chris Ka Pun; Zhu, Wenfei; Zhou, Haibo; He, Jianfeng; Guan, Wenda; Wu, Jie; Song, Wenjun; Wang, Dayan; Liu, Jiexiong; Lin, Qinhan; Chu, Daniel Ka Wing; Yang, Lei; Zhong, Nanshan; Peiris, Joseph Sriyal Malik

2017-01-01

The recent increase in zoonotic avian influenza A(H7N9) disease in China is a cause of public health concern. Most of the A(H7N9) viruses previously reported have been of low pathogenicity. We report the fatal case of a patient in China who was infected with an A(H7N9) virus having a polybasic amino acid sequence at its hemagglutinin cleavage site (PEVPKRKRTAR/GL), a sequence suggestive of high pathogenicity in birds. Its neuraminidase also had R292K, an amino acid change known to be associated with neuraminidase inhibitor resistance. Both of these molecular features might have contributed to the patient’s adverse clinical outcome. The patient had a history of exposure to sick and dying poultry, and his close contacts had no evidence of A(H7N9) disease, suggesting human-to-human transmission did not occur. Enhanced surveillance is needed to determine whether this highly pathogenic avian influenza A(H7N9) virus will continue to spread. PMID:28580899

Human Infection with Highly Pathogenic Avian Influenza A(H7N9) Virus, China.

PubMed

Ke, Changwen; Mok, Chris Ka Pun; Zhu, Wenfei; Zhou, Haibo; He, Jianfeng; Guan, Wenda; Wu, Jie; Song, Wenjun; Wang, Dayan; Liu, Jiexiong; Lin, Qinhan; Chu, Daniel Ka Wing; Yang, Lei; Zhong, Nanshan; Yang, Zifeng; Shu, Yuelong; Peiris, Joseph Sriyal Malik

2017-07-01

The recent increase in zoonotic avian influenza A(H7N9) disease in China is a cause of public health concern. Most of the A(H7N9) viruses previously reported have been of low pathogenicity. We report the fatal case of a patient in China who was infected with an A(H7N9) virus having a polybasic amino acid sequence at its hemagglutinin cleavage site (PEVPKRKRTAR/GL), a sequence suggestive of high pathogenicity in birds. Its neuraminidase also had R292K, an amino acid change known to be associated with neuraminidase inhibitor resistance. Both of these molecular features might have contributed to the patient's adverse clinical outcome. The patient had a history of exposure to sick and dying poultry, and his close contacts had no evidence of A(H7N9) disease, suggesting human-to-human transmission did not occur. Enhanced surveillance is needed to determine whether this highly pathogenic avian influenza A(H7N9) virus will continue to spread.

Avian influenza A (H7N9) virus infection in humans: epidemiology, evolution, and pathogenesis.

PubMed

Husain, Matloob

2014-12-01

New human influenza A virus strains regularly emerge causing seasonal epidemics and occasional pandemics. Lately, several zoonotic avian influenza A strains have been reported to directly infect humans. In early 2013, a novel avian influenza A virus (H7N9) strain was discovered in China to cause severe respiratory disease in humans. Since then, over 450 human cases of H7N9 infection have been discovered and 165 of them have died. Multiple epidemiological, phylogenetic, in vivo, and in vitro studies have been done to determine the origin and pathogenesis of novel H7N9 strain. This article reviews the literature related to the epidemiology, evolution, and pathogenesis of the H7N9 strain since its discovery in February 2013 till August 2014. The data available so far indicate that H7N9 was originated by a two-step reassortment process in birds and transmitted to humans through direct contact with live-bird markets. H7N9 is a low-pathogenic avian virus and contains several molecular signatures for adaptation in mammals. The severity of the respiratory disease caused by novel H7N9 virus in humans can be partly attributed to the age, sex, and underlying medical conditions of the patients. A universal influenza vaccine is not available, though several strain-specific H7N9 candidate vaccine viruses have been developed. Further, novel H7N9 virus is resistant to antiviral drug amantadine and some H7N9 isolates have acquired the resistance to neuraminidase-inhibitors. Therefore, constant surveillance and prompt control measures combined with novel research approaches to develop alternative and effective anti-influenza strategies are needed to overcome influenza A virus. Copyright © 2014 Elsevier B.V. All rights reserved.

Biological Characterizations of H5Nx Avian Influenza Viruses Embodying Different Neuraminidases

PubMed Central

Yu, Yuandi; Zhang, Zaoyue; Li, Huanan; Wang, Xiuhui; Li, Bo; Ren, Xingxing; Zeng, Zhaoyong; Zhang, Xu; Liu, Shukai; Hu, Pingsheng; Qi, Wenbao; Liao, Ming

2017-01-01

The H5 subtype virus of Highly Pathogenic Avian Influenza Virus has caused huge economic losses to the poultry industry and is a threat to human health. Until 2010, H5N1 subtype virus was the major genotype in China. Since 2011, reassortant H5N2, H5N6, and H5N8 viruses were identified in domestic poultry in China. The clade 2.3.4.4 H5N6 and H5N8 AIV has now spread to most of China. Clade 2.3.4.4 H5N6 virus has caused 17 human deaths. However, the prevalence, pathogenicity, and transmissibility of the distinct NA reassortment with H5 subtypes viruses (H5Nx) is unknown. We constructed five clade 2.3.4.4 reassortant H5Nx viruses that shared the same HA and six internal gene segments. The NA gene segment was replaced with N1, N2, N6, ΔN6 (with an 11 amino acid deletion at the 58th to 68th of NA stalk region), and N8 strains, respectively. The reassortant viruses with distinct NAs of clade 2.3.4.4 H5 subtype had different degrees of fitness. All reassortant H5Nx viruses formed plaques on MDCK cell monolayers, but the ΔH5N6 grew more efficiently in mammalian and avian cells. The reassortant H5Nx viruses were more virulent in mice as compared to the H5N2 virus. The H5N6 and H5N8 reassortant viruses exhibited enhanced pathogenicity and transmissibility in chickens as compared to the H5N1 reassortant virus. We suggest that comprehensive surveillance work should be undertaken to monitor the H5Nx viruses. PMID:28659898

Efficacy of Live-Attenuated H9N2 Influenza Vaccine Candidates Containing NS1 Truncations against H9N2 Avian Influenza Viruses.

PubMed

Chen, Sujuan; Zhu, Yinbiao; Yang, Da; Yang, Yang; Shi, Shaohua; Qin, Tao; Peng, Daxin; Liu, Xiufan

2017-01-01

H9N2 avian influenza virus is a zoonotic agent with a broad host range that can contribute genetic information to H5 or H7N9 subtype viruses, which are significant threats to both humans and birds. Thus, there is a great need for a vaccine to control H9N2 avian influenza. Three mutant viruses of an H9N2 virus A/chicken/Taixing/10/2010 (rTX-NS1-73, rTX-NS1-100, and rTX-NS1-128) were constructed with different NS1 gene truncations and confirmed by western blot analysis. The genetic stability, pathogenicity, transmissibility, and host immune responses toward these mutants were evaluated. The mutant virus rTX-NS1-128 exhibited the most attenuated phenotype and lost transmissibility. The expression levels of interleukin 12 in the nasal and tracheal tissues from chickens immunized with rTX-NS1-128 were significantly upregulated on day 3 post-immunization and the IgA and IgG antibody levels were significantly increased on days 7, 14, and 21 post-immunization when compared to chickens that received an inactivated vaccine. rTX-NS1-128 also protected chickens from challenge by homologous and heterologous H9N2 avian influenza viruses. The results indicate that rTX-NS1-128 can be used as a potential live-attenuated vaccine against H9N2 avian influenza.

A Case-Control Study to Identify Risk Factors Associated with Avian Influenza Subtype H9N2 on Commercial Poultry Farms in Pakistan

PubMed Central

Chaudhry, Mamoona; Rashid, Hamad B.; Thrusfield, Michael; Welburn, Sue; Bronsvoort, Barend MdeC.

2015-01-01

A 1:1 matched case-control study was conducted to identify risk factors for avian influenza subtype H9N2 infection on commercial poultry farms in 16 districts of Punjab, and 1 administrative unit of Pakistan. One hundred and thirty-three laboratory confirmed positive case farms were matched on the date of sample submission with 133 negative control farms. The association between a series of farm-level characteristics and the presence or absence of H9N2 was assessed by univariable analysis. Characteristics associated with H9N2 risk that passed the initial screening were included in a multivariable conditional logistic regression model. Manual and automated approaches were used, which produced similar models. Key risk factors from all approaches included selling of eggs/birds directly to live bird retail stalls, being near case/infected farms, a previous history of infectious bursal disease (IBD) on the farm and having cover on the water storage tanks. The findings of current study are in line with results of many other studies conducted in various countries to identify similar risk factors for AI subtype H9N2 infection. Enhancing protective measures and controlling risks identified in this study could reduce spread of AI subtype H9N2 and other AI viruses between poultry farms in Pakistan. PMID:25774768

Risk factors associated with highly pathogenic avian influenza subtype H5N8 outbreaks on broiler duck farms in South Korea.

PubMed

Kim, W-H; An, J-U; Kim, J; Moon, O-K; Bae, S H; Bender, J B; Cho, S

2018-04-19

Highly Pathogenic Avian Influenza (HPAI) subtype H5N8 outbreaks occurred in poultry farms in South Korea in 2014 resulting in significant damage to the poultry industry. Between 2014 and 2016, the pandemic disease caused significant economic loss and social disruption. To evaluate the risk factors for HPAI infection in broiler duck farms, we conducted a retrospective case-control study on broiler duck farms. Forty-three farms with confirmed laboratories on premises were selected as the case group, and 43 HPAI-negative farms were designated as the control group. Control farms were matched based on farm location and were within a 3-km radius from the case premises. Spatial and environmental factors were characterized by site visit and plotted through a geographic information system (GIS). Univariable and multivariable logistic regression models were developed to assess possible risk factors associated with HPAI broiler duck farm infection. Four final variables were identified as risk factors in a final multivariable logistic model: "Farms with ≥7 flocks" (odds ratio [OR] = 6.99, 95% confidence interval [CI] 1.34-37.04), "Farm owner with ≥15 years of raising poultry career" (OR = 7.91, 95% CI 1.69-37.14), "Presence of any poultry farms located within 500 m of the farm" (OR = 6.30, 95% CI 1.08-36.93) and "Not using a faecal removal service" (OR = 27.78, 95% CI 3.89-198.80). This highlights that the HPAI H5N8 outbreaks in South Korea were associated with farm owner education, number of flocks and facilities and farm biosecurity. Awareness of these factors may help to reduce the spread of HPAI H5N8 across broiler duck farms in Korea during epidemics. Greater understanding of the risk factors for H5N8 may improve farm vulnerability to HPAI and other subtypes and help to establish policies to prevent re-occurrence. These findings are relevant to global prevention recommendations and intervention protocols. © 2018 Blackwell Verlag GmbH.

9 CFR 146.14 - Diagnostic surveillance program for H5/H7 low pathogenic avian influenza.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Diagnostic surveillance program for H5/H7 low pathogenic avian influenza. 146.14 Section 146.14 Animals and Animal Products ANIMAL AND PLANT... antigen detection test. Memoranda of understanding or other means must be used to establish testing and...

9 CFR 146.14 - Diagnostic surveillance program for H5/H7 low pathogenic avian influenza.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Diagnostic surveillance program for H5/H7 low pathogenic avian influenza. 146.14 Section 146.14 Animals and Animal Products ANIMAL AND PLANT... antigen detection test. Memoranda of understanding or other means must be used to establish testing and...

9 CFR 146.14 - Diagnostic surveillance program for H5/H7 low pathogenic avian influenza.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Diagnostic surveillance program for H5/H7 low pathogenic avian influenza. 146.14 Section 146.14 Animals and Animal Products ANIMAL AND PLANT... antigen detection test. Memoranda of understanding or other means must be used to establish testing and...

9 CFR 146.14 - Diagnostic surveillance program for H5/H7 low pathogenic avian influenza.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Diagnostic surveillance program for H5/H7 low pathogenic avian influenza. 146.14 Section 146.14 Animals and Animal Products ANIMAL AND PLANT... antigen detection test. Memoranda of understanding or other means must be used to establish testing and...

9 CFR 146.14 - Diagnostic surveillance program for H5/H7 low pathogenic avian influenza.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Diagnostic surveillance program for H5/H7 low pathogenic avian influenza. 146.14 Section 146.14 Animals and Animal Products ANIMAL AND PLANT... antigen detection test. Memoranda of understanding or other means must be used to establish testing and...

[Advances on epidemiological research of human infections with novel avian influenza A (H7N9) virus].

PubMed

Wang, Q M; Liu, S L; Chen, E F

2017-02-06

Human infections with novel avian influenza A(H7N9)virus was an emerging infectious disease discovered in March, 2013. As of June30, 2016, 770 cases of H7N9 were reported in worldwide including 315 deaths with 40.9% of high case fatality rate. Yangtze River Delta and Pearl River Delta were the high-prevalence area. Formerly, the cases of H7N9 were concentrated on the municipalities. However, most of the case-patients were from smaller cities or rural areas nowadays. The H7N9 human infections mainly occurred in winter and spring every waves as similar as seasonal and H5N1 human infections. Middle aged and old (the median age was 61 years) male patients were occupied the large proportion among the cases of H7N9. In addition, the phenomenon of the limited and unsustained human-to-human transmission were existed. At present, the 4 major epidemic waves had happened and human infections with novel avian influenza A (H7N9) virus could be outbreak regularly in China. In this paper, the pathogenic characteristics and disease distribution of H7N9 influenza A viruses were elaborated, with both transmission factors and control measures, which were helpful to provide the scientific evidence for prevention and control in H7N9avian influenza epidemic.

Experimental assessment of houseflies as vectors in avian influenza subtype H5N1 transmission in chickens.

PubMed

Wanaratana, S; Amonsin, A; Chaisingh, A; Panyim, S; Sasipreeyajan, J; Pakpinyo, S

2013-06-01

In this study, laboratory-reared houseflies were experimentally exposed to the high pathogenicity avian influenza virus (HPAI) subtype H5N1 virus to evaluate the houseflies as vectors in HPAI-H5N1 virus transmission in chickens. One hundred and fifty houseflies (Musca domestica L.) were equally allocated into three groups. Groups 2 and 3 were exposed to the HPAI-H5N1 virus by allowing the flies to consume food containing the virus for 15 min, while the flies in group 1 were allowed to consume H5N1-free food and would serve as a negative control group. Group 2 flies were euthanatized immediately after H5N1 exposure, while group 3 were held at room temperature for 24 hr and euthanatized. The houseflies in the transmission of the HPAI-H5N1 virus were examined by challenging three groups of housefly homogenates into layer chickens via the oral drop. Morbidity and mortality were observed for 14 days, and virus shedding monitored via oropharyngeal swabs (OS) and cloacal swabs (CS), which were collected daily and determined by real-time reverse transcription-PCR and virus titration. Experimental challenge showed that all the chickens of groups 2 and 3 died within 7 days of inoculation. The OS had higher concentrations of virus than CS. Moreover, the chickens of group 2 had higher concentrations of virus shedding than the chickens of group 3. Immunohistochemistry detected the nucleoprotein of the type A influenza virus in all tissue samples collected, including the trachea, duodenum, pancreas, and brain. In summary, this study demonstrates that houseflies could serve as vectors in HPAI-H5N1 virus transmission in chickens under experimental conditions.

Simultaneous detection of eight avian influenza A virus subtypes by multiplex reverse transcription-PCR using a GeXP analyser.

PubMed

Li, Meng; Xie, Zhixun; Xie, Zhiqin; Liu, Jiabo; Xie, Liji; Deng, Xianwen; Luo, Sisi; Fan, Qing; Huang, Li; Huang, Jiaoling; Zhang, Yanfang; Zeng, Tingting; Wang, Sheng

2018-04-18

Recent studies have demonstrated that at least eight subtypes of avian influenza virus (AIV) can infect humans, including H1, H2, H3, H5, H6, H7, H9 and H10. A GeXP analyser-based multiplex reverse transcription (RT)-PCR (GeXP-multiplex RT-PCR) assay was developed in our recent studies to simultaneously detect these eight AIV subtypes using the haemagglutinin (HA) gene. The assay consists of chimeric primer-based PCR amplification with fluorescent labelling and capillary electrophoresis separation. RNA was extracted from chick embryo allantoic fluid or liquid cultures of viral isolates. In addition, RNA synthesised via in vitro transcription was used to determine the specificity and sensitivity of the assay. After selecting the primer pairs, their concentrations and GeXP-multiplex RT-PCR conditions were optimised. The established GeXP-multiplex RT-PCR assay can detect as few as 100 copies of premixed RNA templates. In the present study, 120 clinical specimens collected from domestic poultry at live bird markets and from wild birds were used to evaluate the performance of the assay. The GeXP-multiplex RT-PCR assay specificity was the same as that of conventional RT-PCR. Thus, the GeXP-multiplex RT-PCR assay is a rapid and relatively high-throughput method for detecting and identifying eight AIV subtypes that may infect humans.

A Survey of Avian Influenza in Tree Sparrows in China in 2011

PubMed Central

Han, Chunhua; Liu, Shuo; Chen, Jie; Li, Jinping; Zhang, Peng; Huang, Baoxu; Liu, Yuehuan; Chen, Jiming

2012-01-01

Tree sparrows (Passer montanus) are widely distributed in all seasons in many countries. In this study, a survey and relevant experiments on avian influenza (AI) in tree sparrows were conducted. The results suggested that the receptor for avian influenza viruses (AIVs), SAα2,3Gal, is abundant in the respiratory tract of tree sparrows, and most of the tree sparrows infected experimentally with two H5 subtype highly pathogenic avian influenza (HPAI) viruses died within five days after inoculation. Furthermore, no AIVs were isolated from the rectum eluate of 1300 tree sparrows, but 94 serological positives of AI were found in 800 tree sparrows. The serological positives were more prevalent for H5 subtype HPAI (94/800) than for H7 subtype AI (0/800), more prevalent for clade 2.3.2.1 H5 subtype HPAI (89/800) than for clade 2.3.4 (1/800) and clade 7.2 (4/800) H5 subtype HPAI, more prevalent for clade 2.3.2.1 H5 subtype HPAI in a city in southern China (82/800) than in a city in northern China (8/800). The serological data are all consistent with the distribution of the subtypes or clades of AI in poultry in China. Previously, sparrows or other passerine birds were often found to be pathogenically negative for AIVs, except when an AIV was circulating in the local poultry, or the tested passerine birds were from a region near waterfowl-rich bodies of water. Taken together, the data suggest that tree sparrows are susceptible to infection of AIVs, and surveys targeting sparrows can provide good serological data about the circulation of AIVs in relevant regions. PMID:22496742

Influenza A(H7N9) Virus Transmission between Finches and Poultry

PubMed Central

Jones, Jeremy C.; Sonnberg, Stephanie; Webby, Richard J.

2015-01-01

Low pathogenicity avian influenza A(H7N9) virus has been detected in poultry since 2013, and the virus has caused >450 infections in humans. The mode of subtype H7N9 virus transmission between avian species remains largely unknown, but various wild birds have been implicated as a source of transmission. H7N9 virus was recently detected in a wild sparrow in Shanghai, China, and passerine birds, such as finches, which share space and resources with wild migratory birds, poultry, and humans, can be productively infected with the virus. We demonstrate that interspecies transmission of H7N9 virus occurs readily between society finches and bobwhite quail but only sporadically between finches and chickens. Inoculated finches are better able to infect naive poultry than the reverse. Transmission occurs through shared water but not through the airborne route. It is therefore conceivable that passerine birds may serve as vectors for dissemination of H7N9 virus to domestic poultry. PMID:25811839

Assessment of transmission, pathogenesis and adaptation of H2 subtype influenza viruses in ferrets.

PubMed

Pappas, Claudia; Yang, Hua; Carney, Paul J; Pearce, Melissa B; Katz, Jacqueline M; Stevens, James; Tumpey, Terrence M

2015-03-01

After their disappearance from the human population in 1968, influenza H2 viruses have continued to circulate in the natural avian reservoir. The isolation of this virus subtype from multiple bird species as well as swine highlights the need to better understand the potential of these viruses to spread and cause disease in humans. Here we analyzed the virulence, transmissibility and receptor-binding preference of two avian influenza H2 viruses (H2N2 and H2N3) and compared them to a swine H2N3 (A/swine/Missouri/2124514/2006 [swMO]), and a human H2N2 (A/England/10/1967 [Eng/67]) virus using the ferret model as a mammalian host. Both avian H2 viruses possessed the capacity to spread efficiently between cohoused ferrets, and the swine (swMO) and human (Eng/67) viruses transmitted to naïve ferrets by respiratory droplets. Further characterization of the swMO hemagglutinin (HA) by x-ray crystallography and glycan microarray array identified receptor-specific adaptive mutations. As influenza virus quasispecies dynamics during transmission have not been well characterized, we sequenced nasal washes collected during transmission studies to better understand experimental adaptation of H2 HA. The avian H2 viruses isolated from ferret nasal washes contained mutations in the HA1, including a Gln226Leu substitution, which is a mutation associated with α2,6 sialic acid (human-like) binding preference. These results suggest that the molecular structure of HA in viruses of the H2 subtype continue to have the potential to adapt to a mammalian host and become transmissible, after acquiring additional genetic markers. Published by Elsevier Inc.

Assessment of transmission, pathogenesis and adaptation of H2 subtype influenza viruses in ferrets

PubMed Central

Pappas, Claudia; Yang, Hua; Carney, Paul J.; Pearce, Melissa B.; Katz, Jacqueline M.; Stevens, James; Tumpey, Terrence M.

2018-01-01

After their disappearance from the human population in 1968, influenza H2 viruses have continued to circulate in the natural avian reservoir. The isolation of this virus subtype from multiple bird species as well as swine highlights the need to better understand the potential of these viruses to spread and cause disease in humans. Here we analyzed the virulence, transmissibility and receptor-binding preference of two avian influenza H2 viruses (H2N2 and H2N3) and compared them to a swine H2N3 (A/swine/Missouri/2124514/2006 [swMO]), and a human H2N2 (A/England/10/1967 [Eng/67]) virus using the ferret model as a mammalian host. Both avian H2 viruses possessed the capacity to spread efficiently between cohoused ferrets, and the swine (swMO) and human (Eng/67) viruses transmitted to naïve ferrets by respiratory droplets. Further characterization of the swMO hemagglutinin (HA) by x-ray crystallography and glycan microarray array identified receptor-specific adaptive mutations. As influenza virus quasispecies dynamics during transmission have not been well characterized, we sequenced nasal washes collected during transmission studies to better understand experimental adaptation of H2 HA. The avian H2 viruses isolated from ferret nasal washes contained mutations in the HA1, including a Gln226Leu substitution, which is a mutation associated with α2,6 sialic acid (human-like) binding preference. These results suggest that the molecular structure of HA in viruses of the H2 subtype continue to have the potential to adapt to a mammalian host and become transmissible, after acquiring additional genetic markers. PMID:25659818

Deep sequencing of H7N8 avian influenza viruses from surveillance zone supports H7N8 high pathogenicity avian influenza was limited to a single outbreak farm in Indiana during 2016

USDA-ARS?s Scientific Manuscript database

In mid-January 2016, an outbreak of H7N8 high pathogenicity avian influenza (HPAI) virus in commercial turkeys occurred in Indiana. The outbreak was first detected by an increase in mortality followed by laboratory confirmation of H7N8 HPAI virus. Surveillance within the 10 km Control Zone detected...

A live attenuated cold adapted influenza A H7N3 virus vaccine provides protection against homologous and heterologous H7 viruses in mice and ferrets

PubMed Central

Joseph, Tomy; McAuliffe, Josephine; Lu, Bin; Vogel, Leatrice; Swayne, David; Jin, Hong; Kemble, George; Subbarao, Kanta

2008-01-01

The appearance of human infections caused by avian influenza A H7 subtype viruses underscore their pandemic potential and the need to develop vaccines to protect humans from viruses of this subtype. A live attenuated H7N3 virus vaccine was generated by reverse genetics using the HA and NA genes of a low pathogenicity A/chicken/BC/CN-6/04 (H7N3) virus and the six internal protein genes of the cold-adapted A/Ann Arbor/6/60 ca (H2N2) virus. The reassortant H7N3 BC 04 ca vaccine virus was temperature sensitive and showed attenuation in mice and ferrets. Intranasal immunization with one dose of the vaccine protected mice and ferrets when challenged with homologous and heterologous H7 viruses. The reassortant H7N3 BC 04 ca vaccine virus showed comparable levels of attenuation, immunogenicity and efficacy in mice and ferret models. The safety, immunogenicity, and efficacy of this vaccine in mice and ferrets support the evaluation of this vaccine in clinical trials. PMID:18585748

A live attenuated cold-adapted influenza A H7N3 virus vaccine provides protection against homologous and heterologous H7 viruses in mice and ferrets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joseph, Tomy; MedImmune Inc., Mountain View, CA 94043; McAuliffe, Josephine

2008-08-15

The appearance of human infections caused by avian influenza A H7 subtype viruses underscores their pandemic potential and the need to develop vaccines to protect humans from viruses of this subtype. A live attenuated H7N3 virus vaccine was generated by reverse genetics using the HA and NA genes of a low pathogenicity A/chicken/BC/CN-6/04 (H7N3) virus and the six internal protein genes of the cold-adapted A/Ann Arbor/6/60 ca (H2N2) virus. The reassortant H7N3 BC 04 ca vaccine virus was temperature sensitive and showed attenuation in mice and ferrets. Intranasal immunization with one dose of the vaccine protected mice and ferrets whenmore » challenged with homologous and heterologous H7 viruses. The reassortant H7N3 BC 04 ca vaccine virus showed comparable levels of attenuation, immunogenicity and efficacy in mice and ferret models. The safety, immunogenicity, and efficacy of this vaccine in mice and ferrets support the evaluation of this vaccine in clinical trials.« less

Appearance of reassortant European avian-origin H1 influenza A viruses of swine in Vietnam.

PubMed

Takemae, N; Nguyen, P T; Le, V T; Nguyen, T N; To, T L; Nguyen, T D; Pham, V P; Vo, H V; Le, Q V T; Do, H T; Nguyen, D T; Uchida, Y; Saito, T

2018-03-06

Three subtypes-H1N1, H1N2 and H3N2-of influenza A viruses of swine (IAVs-S) are currently endemic in swine worldwide, but there is considerable genotypic diversity among each subtype and limited geographical distribution. Through IAVs-S monitoring in Vietnam, two H1N2 influenza A viruses were isolated from healthy pigs in Ba Ria-Vung Tau Province, Southern Vietnam, on 2 December 2016. BLAST and phylogenetic analyses revealed that their HA and NA genes were derived from those of European avian-like H1N2 IAVs-S that contained avian-origin H1 and human-like N2 genes, and were particularly closely related to those of IAVs-S circulating in the Netherlands, Germany or Denmark. In addition, the internal genes of these Vietnamese isolates were derived from human A(H1N1)pdm09 viruses, suggesting that the Vietnamese H1N2 IAVs-S are reassortants between European H1N2 IAVs-S and human A(H1N1)pdm09v. The appearance of European avian-like H1N2 IAVs-S in Vietnam marks their first transmission outside Europe. Our results and statistical analyses of the number of live pigs imported into Vietnam suggest that the European avian-like H1N2 IAVs-S may have been introduced into Vietnam with their hosts through international trade. These findings highlight the importance of quarantining imported pigs to impede the introduction of new IAVs-S. © 2018 Blackwell Verlag GmbH.

Adaptation of avian influenza A (H6N1) virus from avian to human receptor-binding preference

PubMed Central

Wang, Fei; Qi, Jianxun; Bi, Yuhai; Zhang, Wei; Wang, Min; Zhang, Baorong; Wang, Ming; Liu, Jinhua; Yan, Jinghua; Shi, Yi; Gao, George F

2015-01-01

The receptor-binding specificity of influenza A viruses is a major determinant for the host tropism of the virus, which enables interspecies transmission. In 2013, the first human case of infection with avian influenza A (H6N1) virus was reported in Taiwan. To gather evidence concerning the epidemic potential of H6 subtype viruses, we performed comprehensive analysis of receptor-binding properties of Taiwan-isolated H6 HAs from 1972 to 2013. We propose that the receptor-binding properties of Taiwan-isolated H6 HAs have undergone three major stages: initially avian receptor-binding preference, secondarily obtaining human receptor-binding capacity, and recently human receptor-binding preference, which has been confirmed by receptor-binding assessment of three representative virus isolates. Mutagenesis work revealed that E190V and G228S substitutions are important to acquire the human receptor-binding capacity, and the P186L substitution could reduce the binding to avian receptor. Further structural analysis revealed how the P186L substitution in the receptor-binding site of HA determines the receptor-binding preference change. We conclude that the human-infecting H6N1 evolved into a human receptor preference. PMID:25940072

Avian influenza surveillance in domestic waterfowl and environment of live bird markets in Bangladesh, 2007-2012.

PubMed

Khan, Salah Uddin; Gurley, Emily S; Gerloff, Nancy; Rahman, Md Z; Simpson, Natosha; Rahman, Mustafizur; Haider, Najmul; Chowdhury, Sukanta; Balish, Amanda; Zaman, Rashid Uz; Nasreen, Sharifa; Chandra Das, Bidhan; Azziz-Baumgartner, Eduardo; Sturm-Ramirez, Katharine; Davis, C Todd; Donis, Ruben O; Luby, Stephen P

2018-06-20

Avian influenza viruses, including highly pathogenic strains, pose severe economic, animal and public health concerns. We implemented live bird market surveillance in Bangladesh to identify the subtypes of avian influenza A viruses in domestic waterfowl and market environments. We collected waterfowl samples monthly from 4 rural sites from 2007 to 2012 and environmental samples from 4 rural and 16 urban sites from 2009 to 2012. Samples were tested through real-time RT-PCR, virus culture, and sequencing to detect and characterize avian influenza A viruses. Among 4,308 waterfowl tested, 191 (4.4%) were positive for avian influenza A virus, including 74 (1.9%) avian influenza A/H5 subtype. The majority (99%, n = 73) of the influenza A/H5-positive samples were from healthy appearing waterfowl. Multiple subtypes, including H1N1, H1N3, H3N2, H3N6, H3N8, H4N1, H4N2, H4N6, H5N1 (clades 2.2.2, 2.3.2.1a, 2.3.4.2), H5N2, H6N1, H7N9, H9N2, H11N2 and H11N3, H11N6 were detected in waterfowl and environmental samples. Environmental samples tested positive for influenza A viruses throughout the year. Avian influenza viruses, including H5N1 and H9N2 subtypes were also identified in backyard and small-scale raised poultry. Live bird markets could be high-risk sites for harboring the viruses and have the potential to infect naive birds and humans exposed to them.

Deep sequencing of H7N8 avian influenza viruses from surveillance zone supports H7N8 high pathogenicity avian influenza was limited to a single outbreak farm in Indiana during 2016.

PubMed

Lee, Dong-Hun; Torchetti, Mia Kim; Killian, Mary Lea; Swayne, David E

2017-07-01

In mid-January 2016, an outbreak of H7N8 high-pathogenicity avian influenza virus (HPAIV) in commercial turkeys occurred in Indiana. Surveillance within the 10km control zone identified H7N8 low-pathogenicity avian influenza virus (LPAIV) in nine surrounding turkey flocks but no other HPAIV-affected premises. We sequenced four of the H7N8 HPAIV isolated from the single farm and nine LPAIV identified during control zone surveillance. Evaluation included phylogenetic network analysis indicating close relatedness across the HPAIV and LPAIV, and that the progenitor H7N8 LPAIV spread among the affected turkey farms in Indiana, followed by spontaneous mutation to HPAIV on a single premise through acquisition of three basic amino acids at the hemagglutinin cleavage site. Deep sequencing of the available viruses failed to identify subpopulations in either the HPAIV or LPAIV suggesting mutation to HPAIV likely occurred on a single farm and the HPAIV did not spread to epidemiologically linked LPAIV-affected farms. Published by Elsevier Inc.

Occurrence and Reassortment of Avian Influenza A (H7N9) Viruses Derived from Coinfected Birds in China

PubMed Central

Liu, Wei; Fan, Hang; Raghwani, Jayna; Lam, Tommy Tsan-Yuk; Li, Jing; Pybus, Oliver G.; Yao, Hong-Wu; Wo, Ying; Liu, Kun; An, Xiao-Ping; Pei, Guang-Qian; Li, Hao; Wang, Hong-Yu; Zhao, Jian-Jun; Jiang, Tao; Ma, Mai-Juan; Xia, Xian; Dong, Yan-De; Zhao, Tong-Yan; Jiang, Jia-Fu; Yang, Yin-Hui; Guan, Yi

2014-01-01

ABSTRACT Over the course of two waves of infection, H7N9 avian influenza A virus has caused 436 human infections and claimed 170 lives in China as of July 2014. To investigate the prevalence and genetic diversity of H7N9, we surveyed avian influenza viruses in poultry in Jiangsu province within the outbreak epicenter. We found frequent occurrence of H7N9/H9N2 coinfection in chickens. Molecular clock phylogenetic analysis confirms coinfection by H7N9/H9N2 viruses and also reveals that the identity of the H7N9 outbreak lineage is confounded by ongoing reassortment between outbreak viruses and diverse H9N2 viruses in domestic birds. Experimental inoculation of a coinfected sample in cell culture yielded two reassortant H7N9 strains with polymerase segments from the original H9N2 strain. Ongoing reassortment between the H7N9 outbreak lineage and diverse H9N2 viruses may generate new strains with the potential to infect humans, highlighting the need for continued viral surveillance in poultry and humans. IMPORTANCE We found frequent occurrence of H7N9/H9N2 coinfection in chickens. The H7N9 outbreak lineage is confounded by ongoing reassortment between H7N9 and H9N2 viruses. The importance of H9N2 viruses as the source of novel avian influenza virus infections in humans requires continuous attention. PMID:25210174

Occurrence and reassortment of avian influenza A (H7N9) viruses derived from coinfected birds in China.

PubMed

Liu, Wei; Fan, Hang; Raghwani, Jayna; Lam, Tommy Tsan-Yuk; Li, Jing; Pybus, Oliver G; Yao, Hong-Wu; Wo, Ying; Liu, Kun; An, Xiao-Ping; Pei, Guang-Qian; Li, Hao; Wang, Hong-Yu; Zhao, Jian-Jun; Jiang, Tao; Ma, Mai-Juan; Xia, Xian; Dong, Yan-De; Zhao, Tong-Yan; Jiang, Jia-Fu; Yang, Yin-Hui; Guan, Yi; Tong, Yigang; Cao, Wu-Chun

2014-11-01

Over the course of two waves of infection, H7N9 avian influenza A virus has caused 436 human infections and claimed 170 lives in China as of July 2014. To investigate the prevalence and genetic diversity of H7N9, we surveyed avian influenza viruses in poultry in Jiangsu province within the outbreak epicenter. We found frequent occurrence of H7N9/H9N2 coinfection in chickens. Molecular clock phylogenetic analysis confirms coinfection by H7N9/H9N2 viruses and also reveals that the identity of the H7N9 outbreak lineage is confounded by ongoing reassortment between outbreak viruses and diverse H9N2 viruses in domestic birds. Experimental inoculation of a coinfected sample in cell culture yielded two reassortant H7N9 strains with polymerase segments from the original H9N2 strain. Ongoing reassortment between the H7N9 outbreak lineage and diverse H9N2 viruses may generate new strains with the potential to infect humans, highlighting the need for continued viral surveillance in poultry and humans. We found frequent occurrence of H7N9/H9N2 coinfection in chickens. The H7N9 outbreak lineage is confounded by ongoing reassortment between H7N9 and H9N2 viruses. The importance of H9N2 viruses as the source of novel avian influenza virus infections in humans requires continuous attention. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

The replication of Bangladeshi H9N2 avian influenza viruses carrying genes from H7N3 in mammals

PubMed Central

Shanmuganatham, Karthik K; Jones, Jeremy C; Marathe, Bindumadhav M; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Turner, Jasmine; Rabiul Alam, S M; Kamrul Hasan, M; Akhtar, Sharmin; Seiler, Patrick; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

2016-01-01

H9N2 avian influenza viruses are continuously monitored by the World Health Organization because they are endemic; they continually reassort with H5N1, H7N9 and H10N8 viruses; and they periodically cause human infections. We characterized H9N2 influenza viruses carrying internal genes from highly pathogenic H7N3 viruses, which were isolated from chickens or quail from live-bird markets in Bangladesh between 2010 and 2013. All of the H9N2 viruses used in this study carried mammalian host-specific mutations. We studied their replication kinetics in normal human bronchoepithelial cells and swine tracheal and lung explants, which exhibit many features of the mammalian airway epithelium and serve as a mammalian host model. All H9N2 viruses replicated to moderate-to-high titers in the normal human bronchoepithelial cells and swine lung explants, but replication was limited in the swine tracheal explants. In Balb/c mice, the H9N2 viruses were nonlethal, replicated to moderately high titers and the infection was confined to the lungs. In the ferret model of human influenza infection and transmission, H9N2 viruses possessing the Q226L substitution in hemagglutinin replicated well without clinical signs and spread via direct contact but not by aerosol. None of the H9N2 viruses tested were resistant to the neuraminidase inhibitors. Our study shows that the Bangladeshi H9N2 viruses have the potential to infect humans and highlights the importance of monitoring and characterizing this influenza subtype to better understand the potential risk these viruses pose to humans. PMID:27094903

The replication of Bangladeshi H9N2 avian influenza viruses carrying genes from H7N3 in mammals.

PubMed

Shanmuganatham, Karthik K; Jones, Jeremy C; Marathe, Bindumadhav M; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Turner, Jasmine; Rabiul Alam, S M; Kamrul Hasan, M; Akhtar, Sharmin; Seiler, Patrick; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

2016-04-20

H9N2 avian influenza viruses are continuously monitored by the World Health Organization because they are endemic; they continually reassort with H5N1, H7N9 and H10N8 viruses; and they periodically cause human infections. We characterized H9N2 influenza viruses carrying internal genes from highly pathogenic H7N3 viruses, which were isolated from chickens or quail from live-bird markets in Bangladesh between 2010 and 2013. All of the H9N2 viruses used in this study carried mammalian host-specific mutations. We studied their replication kinetics in normal human bronchoepithelial cells and swine tracheal and lung explants, which exhibit many features of the mammalian airway epithelium and serve as a mammalian host model. All H9N2 viruses replicated to moderate-to-high titers in the normal human bronchoepithelial cells and swine lung explants, but replication was limited in the swine tracheal explants. In Balb/c mice, the H9N2 viruses were nonlethal, replicated to moderately high titers and the infection was confined to the lungs. In the ferret model of human influenza infection and transmission, H9N2 viruses possessing the Q226L substitution in hemagglutinin replicated well without clinical signs and spread via direct contact but not by aerosol. None of the H9N2 viruses tested were resistant to the neuraminidase inhibitors. Our study shows that the Bangladeshi H9N2 viruses have the potential to infect humans and highlights the importance of monitoring and characterizing this influenza subtype to better understand the potential risk these viruses pose to humans.

Highly pathogenic avian influenza virus (H5N1) in experimentally infected adult mute swans.

PubMed

Kalthoff, Donata; Breithaupt, Angele; Teifke, Jens P; Globig, Anja; Harder, Timm; Mettenleiter, Thomas C; Beer, Martin

2008-08-01

Adult, healthy mute swans were experimentally infected with highly pathogenic avian influenza virus A/Cygnus cygnus/Germany/R65/2006 subtype H5N1. Immunologically naive birds died, whereas animals with preexisting, naturally acquired avian influenza virus-specific antibodies became infected asymptomatically and shed virus. Adult mute swans are highly susceptible, excrete virus, and can be clinically protected by preexposure immunity.

Global dynamic analysis of a H7N9 avian-human influenza model in an outbreak region.

PubMed

Chen, Yongxue; Wen, Yongxian

2015-02-21

In 2013 in China a new type of avian influenza virus, H7N9, began to infect humans and had aroused severe fatality in the infected humans. We know that the spread is from poultry to humans, and the H7N9 avian influenza is low pathogenic in the poultry world but highly pathogenic in the human world, but the transmission mechanism is unclear. Since it has no signs of human-to-human transmission and outbreaks are isolated in some cities in China, in order to investigate the transmission mechanism of human infection with H7N9 avian influenza, an eco-epidemiological model in an outbreak region is proposed and analyzed dynamically. Researches and reports show that gene mutation makes the new virus be capable of infecting humans, therefore the mutation factor is taken into account in the model. The global dynamic analysis is conducted, different thresholds are identified, persistence and global qualitative behaviors are obtained. The impact of H7N9 avian influenza on the people population is concerned. Finally, the numerical simulations are carried out to support the theoretical analysis and to investigate the disease control measures. It seems that we may take people׳s hygiene and prevention awareness factor as a significant policy to achieve the aim of both the disease control and the economic returns. Copyright © 2014 Elsevier Ltd. All rights reserved.

Transmission and immunopathology of the avian influenza virus A/Anhui/1/2013 (H7N9) human isolate in three commonly commercialized avian species.

PubMed

Vidaña, B; Dolz, R; Busquets, N; Ramis, A; Sánchez, R; Rivas, R; Valle, R; Cordón, I; Solanes, D; Martínez, J; Majó, N

2018-05-01

H7N9 virus infection is a global concern, given that it can cause severe infection and mortality in humans. However, the understanding of H7N9 epidemiology, animal reservoir species and zoonotic risk remains limited. This work evaluates the pathogenicity, transmissibility and local innate immune response of three avian species harbouring different respiratory distribution of α2,6 and α2,3 SA receptors. Muscovy ducks, European quails and SPF chickens were intranasally inoculated with 10 5 embryo infectious dose (EID) 50 of the human H7N9 (A/Anhui/1/2013) influenza isolate. None of the avian species showed clinical signs or macroscopic lesions, and only mild microscopic lesions were observed in the upper respiratory tract of quail and chickens. Quail presented more severe histopathologic lesions and avian influenza virus (AIV) positivity by immunohistochemistry (IHC), which correlated with higher IL-6 responses. In contrast, Muscovy ducks were resistant to disease and presented higher IFNα and TLR7 response. In all species, viral shedding was higher in the respiratory than in the digestive tract. Higher viral shedding was observed in quail, followed by chicken and ducks, which presented similar viral titres. Efficient transmission was observed in all contact quail and half of the Muscovy ducks, while no transmission was observed between chicken. All avian species showed viral shedding in drinking water throughout infection. © 2017 Blackwell Verlag GmbH.

Free energy simulations reveal a double mutant avian H5N1 virus hemagglutinin with altered receptor binding specificity.

PubMed

Das, Payel; Li, Jingyuan; Royyuru, Ajay K; Zhou, Ruhong

2009-08-01

Historically, influenza pandemics have been triggered when an avian influenza virus or a human/avian reassorted virus acquires the ability to replicate efficiently and become transmissible in the human population. Most critically, the major surface glycoprotein hemagglutinin (HA) must adapt to the usage of human-like (alpha-2,6-linked) sialylated glycan receptors. Therefore, identification of mutations that can switch the currently circulating H5N1 HA receptor binding specificity from avian to human might provide leads to the emergence of pandemic H5N1 viruses. To define such mutations in the H5 subtype, here we provide a computational framework that combines molecular modeling with extensive free energy simulations. Our results show that the simulated binding affinities are in good agreement with currently available experimental data. Moreover, we predict that one double mutation (V135S and A138S) in HA significantly enhances alpha-2,6-linked receptor recognition by the H5 subtype. Our simulations indicate that this double mutation in H5N1 HA increases the binding affinity to alpha-2,6-linked sialic acid receptors by 2.6 +/- 0.7 kcal/mol per HA monomer that primarily arises from the electrostatic interactions. Further analyses reveal that introduction of this double mutation results in a conformational change in the receptor binding pocket of H5N1 HA. As a result, a major rearrangement occurs in the hydrogen-bonding network of HA with the human receptor, making the human receptor binding pattern of double mutant H5N1 HA surprisingly similar to that observed in human H1N1 HA. These large scale molecular simulations on single and double mutants thus provide new insights into our understanding toward human adaptation of the avian H5N1 virus. 2009 Wiley Periodicals, Inc.

75 FR 10645 - Low Pathogenic Avian Influenza; Voluntary Control Program and Payment of Indemnity

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-09

...We are adopting as a final rule, with changes, an interim rule that amended the regulations by establishing, under the auspices of the National Poultry Improvement Plan, a voluntary program for the control of the H5/H7 subtypes of low pathogenic avian influenza in commercial poultry. As amended by this document, the rule provides that the amount of indemnity for which contract growers are eligible will be reduced by any payment they have already received on their contracts when poultry in their care are destroyed, clarifies the roles of cooperating State agencies with respect to H5/H7 low pathogenic avian influenza outbreaks, provides that consistency with humane euthanasia guidelines will be considered when selecting a method for the destruction of poultry, and provides additional guidance for cleaning and disinfecting an affected premises. The control program and indemnity provisions established by the interim rule are necessary to help ensure that the H5/H7 subtypes of low pathogenic avian influenza are detected and eradicated when they occur within the United States.

76 FR 66032 - Availability of an Environmental Assessment for Field Testing Avian Influenza-Marek's Disease...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-25

... Avian Influenza-Marek's Disease Vaccine, H5 Subtype, Serotype 3, Live Marek's Disease Vector AGENCY...-Marek's Disease Vaccine, H5 Subtype, Serotype 3, Live Marek's Disease Vector. The environmental... product: Requester: Biomune Company. Product: Avian Influenza-Marek's Disease Vaccine, H5 Subtype...

Laboratory preparedness in EU/EEA countries for detection of novel avian influenza A(H7N9) virus, May 2013

PubMed Central

Broberg, E; Pereyaslov, D; Struelens, M; Palm, D; Meijer, A; Ellis, J; Zambon, M; McCauley, J; Daniels, R

2015-01-01

Following human infections with novel avian influenza A(H7N9) viruses in China, the European Centre for Disease Prevention and Control, the World Health Organization (WHO) Regional Office for Europe and the European Reference Laboratory Network for Human Influenza (ERLI-Net) rapidly posted relevant information, including real-time RT-PCR protocols. An influenza RNA sequence-based computational assessment of detection capabilities for this virus was conducted in 32 national influenza reference laboratories in 29 countries, mostly WHO National Influenza Centres participating in the WHO Global Influenza Surveillance and Response System (GISRS). Twenty-seven countries considered their generic influenza A virus detection assay to be appropriate for the novel A(H7N9) viruses. Twenty-two countries reported having containment facilities suitable for its isolation and propagation. Laboratories in 27 countries had applied specific H7 real-time RT-PCR assays and 20 countries had N9 assays in place. Positive control virus RNA was provided by the WHO Collaborating Centre in London to 34 laboratories in 22 countries to allow evaluation of their assays. Performance of the generic influenza A virus detection and H7 and N9 subtyping assays was good in 24 laboratories in 19 countries. The survey showed that ERLI-Net laboratories had rapidly developed and verified good capability to detect the novel A(H7N9) influenza viruses. PMID:24507469

Mammalian Models for the Study of H7 Virus Pathogenesis and Transmission

PubMed Central

Belser, Jessica A.; Tumpey, Terrence M.

2018-01-01

Mammalian models, most notably the mouse and ferret, have been instrumental in the assessment of avian influenza virus pathogenicity and transmissibility, and have been used widely to characterize the molecular determinants that confer H5N1 virulence in mammals. However, while H7 influenza viruses have typically been associated with conjunctivitis and/or mild respiratory disease in humans, severe disease and death is also possible, as underscored by the recent emergence of H7N9 viruses in China. Despite the public health need to understand the pandemic potential of this virus subtype, H7 virus pathogenesis and transmission has not been as extensively studied. In this review, we discuss the heterogeneity of H7 subtype viruses isolated from humans, and the characterization of mammalian models to study the virulence of H7 subtype viruses associated with human infection, including viruses of both high and low pathogenicity and following multiple inoculation routes. The use of the ferret transmission model to assess the influence of receptor binding preference among contemporary H7 influenza viruses is described. These models have enabled the study of preventative and therapeutic agents, including vaccines and antivirals, to reduce disease burden, and have permitted a greater appreciation that not all highly pathogenic influenza viruses are created equal. PMID:24996862

[Avian influenza virus in various environments and risk factors for the contamination of live poultry markets during winter and spring season in Zhejiang province].

PubMed

Wang, Xiaoxiao; Cheng, Wei; Yu, Zhao; Mao, Haiyan; Chen, Enfu

2016-03-01

To evaluate the prevalence of avian influenza virus in various environment and the influence factors for subtype H7 prevalence in live poultry markets. We collected environmental samples from various environments across 11 cities of Zhejiang province between October 2014 and March 2015. Cage surface swabs, chopping board surface swabs, feces, water for cleaning, drinking water and swabs of other surfaces were collected. A total of 6 457 samples were collected, including 4 487 samples from poultry markets, 820 samples from poultry farms, 715 samples from backyard poultry pens, 118 samples from poultry processing factories, 118 samples from wild bird habitats and 86 samples from other sites. The chi-squared test was used to compare virus prevalence among sample types, sites types, and poultry markets types. Binary logistic regression was used to analyze factors on H7 subtype prevalence in poultry markets. Of 6 457 samples, 32.54% (2 101) samples were positive for avian influenza, with 3.67% (237) positive for H5 subtype, 12.02%(776) positive for H7 subtype, 11.77%(760) positive for H9 subtype. Of 237 live poultry markets, 33.8% (80) were positive for H7 subtype. The prevalence of influenza A in poultry processing factories was the highest at 43.72% (101/231) (χ(2)=737.80, P<0.001). Poultry markets were contaminated most seriously by subtype H5/H7/H9 with the prevalence of 27.55% (1 236/4 487) (χ(2)=436.37, P<0.001). Compared with markets with 1 type of poultry, OR was 4.58 (95%CI: 1.63-12.87) for markets with ≥2 types of poultry. Live poultry markets and poultry processing factories were contaminated most seriously by avian influenza. The types of poultry might be the factor which influenced the subtype H7 prevalence in poultry markets.

The hemagglutinin structure of an avian H1N1 influenza A virus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, Tianwei; Wang, Gengyan; Li, Anzhang

2009-09-15

The interaction between hemagglutinin (HA) and receptors is a kernel in the study of evolution and host adaptation of H1N1 influenza A viruses. The notion that the avian HA is associated with preferential specificity for receptors with Sia{alpha}2,3Gal glycosidic linkage over those with Sia{alpha}2,6Gal linkage is not all consistent with the available data on H1N1 viruses. By x-ray crystallography, the HA structure of an avian H1N1 influenza A virus, as well as its complexes with the receptor analogs, was determined. The structures revealed no preferential binding of avian receptor analogs over that of the human analog, suggesting that the HA/receptormore » binding might not be as stringent as is commonly believed in determining the host receptor preference for some subtypes of influenza viruses, such as the H1N1 viruses. The structure also showed difference in glycosylation despite the preservation of related sequences, which may partly contribute to the difference between structures of human and avian origin.« less

Avian influenza virus (H5N1): a threat to human health.

PubMed

Peiris, J S Malik; de Jong, Menno D; Guan, Yi

2007-04-01

Pandemic influenza virus has its origins in avian influenza viruses. The highly pathogenic avian influenza virus subtype H5N1 is already panzootic in poultry, with attendant economic consequences. It continues to cross species barriers to infect humans and other mammals, often with fatal outcomes. Therefore, H5N1 virus has rightly received attention as a potential pandemic threat. However, it is noted that the pandemics of 1957 and 1968 did not arise from highly pathogenic influenza viruses, and the next pandemic may well arise from a low-pathogenicity virus. The rationale for particular concern about an H5N1 pandemic is not its inevitability but its potential severity. An H5N1 pandemic is an event of low probability but one of high human health impact and poses a predicament for public health. Here, we review the ecology and evolution of highly pathogenic avian influenza H5N1 viruses, assess the pandemic risk, and address aspects of human H5N1 disease in relation to its epidemiology, clinical presentation, pathogenesis, diagnosis, and management.

Transmission of an H5N8-Subtype Highly Pathogenic Avian Influenza Virus from Infected Hens to Laid Eggs.

PubMed

Uchida, Yuko; Takemae, Nobuhiro; Tanikawa, Taichiro; Kanehira, Katsushi; Saito, Takehiko

2016-06-01

We showed here that an H5N8-subtype highly pathogenic avian influenza virus (HPAIV) was transmitted to both the internal contents and shells of eggs laid by white leghorn hens experimentally infected with the virus. Seven of eight HPAIV-infected hens laid eggs until 4 days postinoculation (dpi). The mean number of eggs laid per head daily decreased significantly from 0.58 before inoculation to 0.18 after viral inoculation. The virus was detected in the eggs laid by three of the seven hens. Viral transmission was detectable beginning on 3 dpi, and virus titers in tracheal and cloacal swabs from the hens that laid the contaminated eggs exceeded 2.9 log10 EID50. The level of viral replication and its timing when virus replicates enough to be detected in oviduct after virus inoculation appear to be key factors in the transmission of H5N8 HPAIV from infected hens to laid eggs.

Possible role of songbirds and parakeets in transmission of influenza A(H7N9) virus to humans.

PubMed

Jones, Jeremy C; Sonnberg, Stephanie; Koçer, Zeynep A; Shanmuganatham, Karthik; Seiler, Patrick; Shu, Yuelong; Zhu, Huachen; Guan, Yi; Peiris, Malik; Webby, Richard J; Webster, Robert G

2014-03-01

Avian-origin influenza A(H7N9) recently emerged in China, causing severe human disease. Several subtype H7N9 isolates contain influenza genes previously identified in viruses from finch-like birds. Because wild and domestic songbirds interact with humans and poultry, we investigated the susceptibility and transmissibility of subtype H7N9 in these species. Finches, sparrows, and parakeets supported replication of a human subtype H7N9 isolate, shed high titers through the oropharyngeal route, and showed few disease signs. Virus was shed into water troughs, and several contact animals seroconverted, although they shed little virus. Our study demonstrates that a human isolate can replicate in and be shed by such songbirds and parakeets into their environment. This finding has implications for these birds' potential as intermediate hosts with the ability to facilitate transmission and dissemination of A(H7N9) virus.

Possible Role of Songbirds and Parakeets in Transmission of Influenza A(H7N9) Virus to Humans

PubMed Central

Jones, Jeremy C.; Sonnberg, Stephanie; Koçer, Zeynep A.; Shanmuganatham, Karthik; Seiler, Patrick; Shu, Yuelong; Zhu, Huachen; Guan, Yi; Peiris, Malik; Webby, Richard J.

2014-01-01

Avian-origin influenza A(H7N9) recently emerged in China, causing severe human disease. Several subtype H7N9 isolates contain influenza genes previously identified in viruses from finch-like birds. Because wild and domestic songbirds interact with humans and poultry, we investigated the susceptibility and transmissibility of subtype H7N9 in these species. Finches, sparrows, and parakeets supported replication of a human subtype H7N9 isolate, shed high titers through the oropharyngeal route, and showed few disease signs. Virus was shed into water troughs, and several contact animals seroconverted, although they shed little virus. Our study demonstrates that a human isolate can replicate in and be shed by such songbirds and parakeets into their environment. This finding has implications for these birds’ potential as intermediate hosts with the ability to facilitate transmission and dissemination of A(H7N9) virus. PMID:24572739

Outbreak patterns of the novel avian influenza (H7N9)

NASA Astrophysics Data System (ADS)

Pan, Ya-Nan; Lou, Jing-Jing; Han, Xiao-Pu

2014-05-01

The attack of novel avian influenza (H7N9) in East China caused a serious health crisis and public panic. In this paper, we empirically analyze the onset patterns of human cases of the novel avian influenza and observe several spatial and temporal properties that are similar to other infectious diseases. More specifically, using the empirical analysis and modeling studies, we find that the spatio-temporal network that connects the cities with human cases along the order of outbreak timing emerges two-regime-power-law edge-length distribution, indicating the picture that several islands with higher and heterogeneous risk straggle in East China. The proposed method is applicable to the analysis of the spreading situation in the early stage of disease outbreak using quite limited dataset.

Genesis, Evolution and Prevalence of H5N6 Avian Influenza Viruses in China.

PubMed

Bi, Yuhai; Chen, Quanjiao; Wang, Qianli; Chen, Jianjun; Jin, Tao; Wong, Gary; Quan, Chuansong; Liu, Jun; Wu, Jun; Yin, Renfu; Zhao, Lihua; Li, Mingxin; Ding, Zhuang; Zou, Rongrong; Xu, Wen; Li, Hong; Wang, Huijun; Tian, Kegong; Fu, Guanghua; Huang, Yu; Shestopalov, Alexander; Li, Shoujun; Xu, Bing; Yu, Hongjie; Luo, Tingrong; Lu, Lin; Xu, Xun; Luo, Yang; Liu, Yingxia; Shi, Weifeng; Liu, Di; Gao, George Fu

2016-12-14

Constant surveillance of live poultry markets (LPMs) is currently the best way to predict and identify emerging avian influenza viruses (AIVs) that pose a potential threat to public health. Through surveillance of LPMs from 16 provinces and municipalities in China during 2014-2016, we identified 3,174 AIV-positive samples and isolated and sequenced 1,135 AIVs covering 31 subtypes. Our analysis shows that H5N6 has replaced H5N1 as one of the dominant AIV subtypes in southern China, especially in ducks. Phylogenetic analysis reveals that H5N6 arose from reassortments of H5 and H6N6 viruses, with the hemagglutinin and neuraminidase combinations being strongly lineage specific. H5N6 viruses constitute at least 34 distinct genotypes derived from various evolutionary pathways. Notably, genotype G1.2 virus, with internal genes from the chicken H9N2/H7N9 gene pool, was responsible for at least five human H5N6 infections. Our findings highlight H5N6 AIVs as potential threats to public health and agriculture. Copyright © 2016. Published by Elsevier Inc.

Inactivation of the novel avian influenza A (H7N9) virus under physical conditions or chemical agents treatment.

PubMed

Zou, Shumei; Guo, Junfeng; Gao, Rongbao; Dong, Libo; Zhou, Jianfang; Zhang, Ye; Dong, Jie; Bo, Hong; Qin, Kun; Shu, Yuelong

2013-09-15

In the spring of 2013, a novel avian-origin influenza A (H7N9) virus in Eastern China emerged causing human infections. Concerns that a new influenza pandemic could occur were raised. The potential effect of chemical agents and physical conditions on inactivation of the novel avian influenza H7N9 virus had not been assessed. To determine the inactivation effectiveness of the novel avian influenza A (H7N9) virus under various physical conditions and chemical treatments, two H7N9 viruses A/Anhui/1/2013 and A/Shanghai/1/2013 were treated by varied temperatures, ultraviolet light, varied pHs and different disinfectants. The viruses with 107.7 EID50 were exposed to physical conditions (temperature, ultraviolet light and pH) or treated with commercial chemical agents (Sodium Hypochlorite, Virkon®-S, and Ethanol) respectively. After these treatments, the viruses were inoculated in SPF embryonated chicken eggs, the allantoic fluid was collected after 72-96 hours culture at 35°C and tested by haemagglutination assay. Both of the tested viruses could tolerate conditions under 56°C for 15 minutes or 60°C for 5 minutes, but their infectivity was completely lost under 56°C for 30 minutes, 65°C for 10 minutes, 70°C, 75°C and 100°C for 1 minute. It was also observed that the H7N9 viruses lost their infectivity totally after exposure of ultraviolet light irradiation for 30 minutes or longer time. Additionally, the viruses were completely inactivated at pH less than 2 for 0.5 hour or pH 3 for 24 hours, however, viruses remained infectious under pH treatment of 4-12 for 24 hours. The viruses were totally disinfected when treated with Sodium Hypochlorite, Virkon®-S and Ethanol at recommended concentrations after only 5 minutes. The novel avian influenza A (H7N9) virus can be inactivated under some physical conditions or with chemical treatments, but they present high tolerance to moderately acidic or higher alkali conditions. The results provided the essential information

Simultaneous subtyping and pathotyping of avian influenza viruses in chickens in Taiwan using reverse transcription loop-mediated isothermal amplification and microarray

PubMed Central

WANG, Lih-Chiann; HUANG, Dean; CHEN, Hui-Wen

2016-01-01

The H6N1 avian influenza virus has circulated in Taiwan for more than 40 years. The sporadic activity of low pathogenic H5N2 virus has been noted since 2003, and highly pathogenic H5N2 avian influenza virus has been detected since 2008. Ressortant viruses between H6N1 and H5N2 viruses have become established and enzootic in chickens throughout Taiwan. Outbreaks caused by Novel highly pathogenic H5 avian influenza viruses whose HA genes were closely related to that of the H5N8 virus isolated from ducks in Korea in 2014 were isolated from outbreaks in Taiwan since early 2015. The avian influenza virus infection status is becoming much more complicated in chickens in Taiwan. This necessitates a rapid and simple approach to detect and differentiate the viruses that prevail. H6N1, H5N2 and novel H5 viruses were simultaneously subtyped and pathotyped in this study using reverse transcription loop-mediated isothermal amplification and microarray, with detection limits of 10°, 101 and 10° viral copy numbers, respectively. The microarray signals were read by the naked eye with no expensive equipment needed. The method developed in this study could greatly improve avian influenza virus surveillance efficiency. PMID:27086860

Prolonged evolution of virus-specific memory T cell immunity post severe avian influenza A (H7N9) virus infection.

PubMed

Zhao, Min; Chen, Junbo; Tan, Shuguang; Dong, Tao; Jiang, Hui; Zheng, Jiandong; Quan, Chuansong; Liao, Qiaohong; Zhang, Hangjie; Wang, Xiling; Wang, Qianli; Bi, Yuhai; Liu, Fengfeng; Feng, Luzhao; Horby, Peter W; Klenerman, Paul; Gao, George F; Liu, William J; Yu, Hongjie

2018-06-20

Since 2013, influenza A/H7N9 has emerged as the commonest avian influenza subtype causing human infection, and is associated with a high fatality risk. However, the characteristics of immune memory in patients who have recovered from H7N9 infection are not well understood. We assembled a cohort of forty-five H7N9 survivors followed for up to 15 months after infection. Humoral and cellular immune responses were analyzed in sequential samples obtained at 1.5-4 months, 6-8 months and 12-15 months post-infection. H7N9-specific antibody concentrations declined over time, and protective antibodies persisted longer in severely ill patients admitted to ICU and patients presenting with ARDS than that in patients with mild disease. Frequencies of virus-specific IFN-γ secreting T cells were lower in critically ill patients requiring ventilation than those in patients without ventilation within four months after infection. The percentages of H7N9-specific IFN-γ secreting T cells tended to increase over time in patients ≥60 years or critically ill patients requiring ventilation. Elevated levels of antigen-specific CD8 + T cells expressing lung-homing marker CD49a were observed at 6-8 months after H7N9 infection compared to samples obtained at 1.5-4 months. Our findings indicate the prolonged reconstruction and evolution of virus-specific T cell immunity in older or critically ill patients, and provide implications for T-cell directed immunization strategies. IMPORTANCE Avian influenza A H7N9 remains a major threat to public health. However, no previous studies have determined the characteristics and dynamics of virus specific T cell immune memory in patients who have recovered from H7N9 infection. Our findings showed that establishment of H7N9-specific T cell memory after H7N9 infection was prolonged in older and severely affected patients. Severely ill patients mounted lower T cell responses in the first 4 months after infection, while T cell responses tended to increase

Comparative analysis of selected innate immune-related genes following infection of immortal DF-1 cells with highly pathogenic (H5N1) and low pathogenic (H9N2) avian influenza viruses.

PubMed

Liu, Ai-Ling; Li, Yu-Feng; Qi, Wenbao; Ma, Xiu-Li; Yu, Ke-Xiang; Huang, Bing; Liao, Ming; Li, Feng; Pan, Jie; Song, Min-Xun

2015-04-01

H5N1 and H9N2 viruses are important causes of avian influenza in China. H5N1 is typically associated with severe to fatal disease in poultry, while H9N2 is usually associated with mild disease. Differences in viral virulence prompted us to investigate whether innate immune responses would be differentially regulated following infection by H5N1 and H9N2 viruses. To address this hypothesis, expression of a panel of innate immune-related genes including IFN-α, IFN-β, Mx1, OASL, ISG12, IFIT5, IRF7, USP18, SST, and KHSRP in immortal DF-1 cells following H5N1 and H9N2 infection was analyzed and compared by real-time quantitative RT-PCR. Cells infected by either virus overall exhibited a similar expression profile for four ISGs (Mx1, OASL, ISG12, and IFIT5), IFN-α, IFN-β, and SST gene. However, two immune-regulatory genes (IRF7 and KHSRP) were not responsive to highly pathogenic H5N1 infection but were strongly up-regulated in DF-1 cells infected with low pathogenic H9N2 infection. The subtype-dependent host response observed in this study offers new insights into the potential roles of IRF7 and KHSRP in control and modulation of the replication and virulence of different subtypes or strains of avian influenza A virus.

Risk perceptions for avian influenza virus infection among poultry workers, China.

PubMed

Yu, Qi; Liu, Linqing; Pu, Juan; Zhao, Jingyi; Sun, Yipeng; Shen, Guangnian; Wei, Haitao; Zhu, Junjie; Zheng, Ruifeng; Xiong, Dongyan; Liu, Xiaodong; Liu, Jinhua

2013-02-01

To determine risk for avian influenza virus infection, we conducted serologic surveillance for H5 and H9 subtypes among poultry workers in Beijing, China, 2009-2010, and assessed workers' understanding of avian influenza. We found that poultry workers had considerable risk for infection with H9 subtypes. Increasing their knowledge could prevent future infections.

Natural Reassortants of Potentially Zoonotic Avian Influenza Viruses H5N1 and H9N2 from Egypt Display Distinct Pathogenic Phenotypes in Experimentally Infected Chickens and Ferrets.

PubMed

Naguib, Mahmoud M; Ulrich, Reiner; Kasbohm, Elisa; Eng, Christine L P; Hoffmann, Donata; Grund, Christian; Beer, Martin; Harder, Timm C

2017-12-01

The cocirculation of zoonotic highly pathogenic avian influenza virus (HPAIV) of subtype H5N1 and avian influenza virus (AIV) of subtype H9N2 among poultry in Egypt for at least 6 years should render that country a hypothetical hot spot for the emergence of reassortant, phenotypically altered viruses, yet no reassortants have been detected in Egypt. The present investigations proved that reassortants of the Egyptian H5N1 clade 2.2.1.2 virus and H9N2 virus of the G1-B lineage can be generated by coamplification in embryonated chicken eggs. Reassortants were restricted to the H5N1 subtype and acquired between two and all six of the internal segments of the H9N2 virus. Five selected plaque-purified reassortant clones expressed a broad phenotypic spectrum both in vitro and in vivo Two groups of reassortants were characterized to have retarded growth characteristics in vitro compared to the H5N1 parent virus. One clone provoked reduced mortality in inoculated chickens, although the characteristics of a highly pathogenic phenotype were retained. Enhanced zoonotic properties were not predicted for any of these clones, and this prediction was confirmed by ferret inoculation experiments: neither the H5N1 parent virus nor two selected clones induced severe clinical symptoms or were transmitted to sentinel ferrets by contact. While the emergence of reassortants of Egyptian HPAIV of subtype H5N1 with internal gene segments of cocirculating H9N2 viruses is possible in principle, the spread of such viruses is expected to be governed by their fitness to outcompete the parental viruses in the field. The eventual spread of attenuated phenotypes, however, would negatively impact syndrome surveillance on poultry farms and might foster enzootic virus circulation. IMPORTANCE Despite almost 6 years of the continuous cocirculation of highly pathogenic avian influenza virus H5N1 and avian influenza virus H9N2 in poultry in Egypt, no reassortants of the two subtypes have been reported

Natural Reassortants of Potentially Zoonotic Avian Influenza Viruses H5N1 and H9N2 from Egypt Display Distinct Pathogenic Phenotypes in Experimentally Infected Chickens and Ferrets

PubMed Central

Naguib, Mahmoud M.; Ulrich, Reiner; Kasbohm, Elisa; Eng, Christine L. P.; Hoffmann, Donata; Grund, Christian; Beer, Martin

2017-01-01

ABSTRACT The cocirculation of zoonotic highly pathogenic avian influenza virus (HPAIV) of subtype H5N1 and avian influenza virus (AIV) of subtype H9N2 among poultry in Egypt for at least 6 years should render that country a hypothetical hot spot for the emergence of reassortant, phenotypically altered viruses, yet no reassortants have been detected in Egypt. The present investigations proved that reassortants of the Egyptian H5N1 clade 2.2.1.2 virus and H9N2 virus of the G1-B lineage can be generated by coamplification in embryonated chicken eggs. Reassortants were restricted to the H5N1 subtype and acquired between two and all six of the internal segments of the H9N2 virus. Five selected plaque-purified reassortant clones expressed a broad phenotypic spectrum both in vitro and in vivo. Two groups of reassortants were characterized to have retarded growth characteristics in vitro compared to the H5N1 parent virus. One clone provoked reduced mortality in inoculated chickens, although the characteristics of a highly pathogenic phenotype were retained. Enhanced zoonotic properties were not predicted for any of these clones, and this prediction was confirmed by ferret inoculation experiments: neither the H5N1 parent virus nor two selected clones induced severe clinical symptoms or were transmitted to sentinel ferrets by contact. While the emergence of reassortants of Egyptian HPAIV of subtype H5N1 with internal gene segments of cocirculating H9N2 viruses is possible in principle, the spread of such viruses is expected to be governed by their fitness to outcompete the parental viruses in the field. The eventual spread of attenuated phenotypes, however, would negatively impact syndrome surveillance on poultry farms and might foster enzootic virus circulation. IMPORTANCE Despite almost 6 years of the continuous cocirculation of highly pathogenic avian influenza virus H5N1 and avian influenza virus H9N2 in poultry in Egypt, no reassortants of the two subtypes have been

Novel Reassortant Clade 2.3.4.4 Avian Influenza A(H5N8) Virus in Wild Aquatic Birds, Russia, 2016.

PubMed

Lee, Dong-Hun; Sharshov, Kirill; Swayne, David E; Kurskaya, Olga; Sobolev, Ivan; Kabilov, Marsel; Alekseev, Alexander; Irza, Victor; Shestopalov, Alexander

2017-02-01

The emergence of novel avian influenza viruses in migratory birds is of concern because of the potential for virus dissemination during fall migration. We report the identification of novel highly pathogenic avian influenza viruses of subtype H5N8, clade 2.3.4.4, and their reassortment with other avian influenza viruses in waterfowl and shorebirds of Siberia.

A human-infecting H10N8 influenza virus retains a strong preference for avian-type receptors

DOE PAGES

Zhang, Heng; de Vries, Robert  P.; Tzarum, Netanel; ...

2015-03-11

Recent avian-origin H10N8 influenza A viruses that have infected humans pose a potential pandemic threat. Alterations in the viral surface glycoprotein, hemagglutinin (HA), typically are required for influenza A viruses to cross the species barrier for adaptation to a new host, but whether H10N8 contains adaptations supporting human infection remains incompletely understood. In this paper, we investigated whether H10N8 HA can bind human receptors. Sialoside glycan microarray analysis showed that the H10 HA retains a strong preference for avian receptor analogs and negligible binding to human receptor analogs. Crystal structures of H10 HA with avian and human receptor analogs revealedmore » the basis for preferential recognition of avian-like receptors. Furthermore, introduction of mutations into the H10 receptor-binding site (RBS) known to convert other HA subtypes from avian to human receptor specificity failed to switch preference to human receptors. In conclusion, collectively these findings suggest that the current H10N8 human isolates are poorly adapted for efficient human-to-human transmission.« less

A human-infecting H10N8 influenza virus retains a strong preference for avian-type receptors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Heng; de Vries, Robert  P.; Tzarum, Netanel

Recent avian-origin H10N8 influenza A viruses that have infected humans pose a potential pandemic threat. Alterations in the viral surface glycoprotein, hemagglutinin (HA), typically are required for influenza A viruses to cross the species barrier for adaptation to a new host, but whether H10N8 contains adaptations supporting human infection remains incompletely understood. In this paper, we investigated whether H10N8 HA can bind human receptors. Sialoside glycan microarray analysis showed that the H10 HA retains a strong preference for avian receptor analogs and negligible binding to human receptor analogs. Crystal structures of H10 HA with avian and human receptor analogs revealedmore » the basis for preferential recognition of avian-like receptors. Furthermore, introduction of mutations into the H10 receptor-binding site (RBS) known to convert other HA subtypes from avian to human receptor specificity failed to switch preference to human receptors. In conclusion, collectively these findings suggest that the current H10N8 human isolates are poorly adapted for efficient human-to-human transmission.« less

Two avian H10 influenza A virus strains with different pathogenicity for mink (Mustela vison).

PubMed

Englund, L; Hård af Segerstad, C

1998-01-01

We compared two strains of avian influenza A viruses of subtype H10 by exposing mink to aerosols of A/mink/Sweden/3,900/84 (H10N4) naturally pathogenic for mink, or A/chicken/Germany/N/49, (H10N7). Lesions in the respiratory tract during the first week after infection were studied and described. Both virus strains caused inflammatory reactions in the lungs and antibody production in exposed mink but only mink/84 virus was reisolated. The lesions caused by mink/84 virus were more severe with higher area density of pneumonia, lower daily weight gain, and more virus in the tissues detected by immunohistochemistry. The results indicate that mink/84 (H10N4), but not chicken/49 virus (H10N7), established multiple cycle replication in infected cells in the mink.

Characterization of highly pathogenic avian influenza H5N8 virus from Egyptian domestic waterfowl in 2017.

PubMed

Anis, Anis; AboElkhair, Mohammed; Ibrahim, Mahmoud

2018-08-01

In 2016, the highly pathogenic avian influenza (HPAI) H5N8 virus was detected in wild birds for the first time in Egypt. In the present study, we identified the HPAI virus H5N8 of clade 2.3.4.4 from domestic waterfowl in Egypt, suggesting its transmission to the domestic poultry from the migratory birds. Based on partial haemagglutinin gene sequence, this virus has a close genetic relationship with subtype H5N8 viruses circulating in Asia and Europe. Pathologically, H5N8 virus in hybrid duck induced nervous signs accompanied by encephalomalacia, haemorrhages, nonsuppurative encephalitis and nonsuppurative vasculitis. The granular layer of cerebellum showed multifocal areas of hydropic degeneration and the Purkinje cell neurons were necrotized or lost. Additionally, the lung, kidney and spleen were congested, and necrotizing pancreatitis was also observed. The co-circulation of both HPAI H5N1 and H5N8 subtypes with the low pathogenic avian influenza H9N2 subtype complicate the control of avian influenza in Egypt with the possibility of emergence of new reassortant viruses. Therefore, continuous monitoring with implementation of strict control measures is required. Research highlights HPAI H5N8 virus clade 2.3.4.4 was detected in domestic ducks and geese in Egypt in 2017. Phylogenetically, the virus was closely related to HPAI H5N8 viruses identified in Asia and Europe Nonsuppurative encephalitis was widely observed in HPAI H5N8 virus-infected ducks. Degeneration of the cerebellar granular layer was found in most of the brain tissues examined.

[Role of noninvasive mechanical ventilation in patients with severe avian influenza A (H7N9) complicated with acute respiratory distress syndrome].

PubMed

Luo, Haili; Wang, Shaohong; Shen, Feng; Yuan, Tongmei; Pan, Xianguo; Liu, Jingtao; Yao, Ling; Wu, Juncheng; Long, Xuemei

2018-05-01

Human infection with avian influenza A (H7N9) is an acute contagious respiratory disease. Acute respiratory distress syndrome (ARDS) is a common complication in patients with severe avian influenza A (H7N9), for whom mechanical ventilation (MV) is an important supportive method. A patient, suffered from severe avian influenza A (H7N9) and complicated with ARDS, was admitted to the Second Affiliated Hospital of Guizhou Medical University in January 2017. With very intensive care for oxygenation, respiration and consciousness, and monitoring, she was successfully cured by comprehensive managements, among which noninvasive mechanical ventilation (NIV) was the major respiratory support method. The result demonstrate that, in patients with conscious state, satisfied expectoration ability and relatively good cooperation, and with close observation of oxygenation and respiratory rate, NIV may be accepted as an effective method for patient with ARDS caused by severe avian influenza A (H7N9).

Neuraminidase Subtyping of Avian Influenza Viruses with PrimerHunter-Designed Primers and Quadruplicate Primer Pools

PubMed Central

Huang, Yanyan; Khan, Mazhar; Măndoiu, Ion I.

2013-01-01

We have previously developed a software package called PrimerHunter to design primers for PCR-based virus subtyping. In this study, 9 pairs of primers were designed with PrimerHunter and successfully used to differentiate the 9 neuraminidase (NA) genes of avian influenza viruses (AIVs) in multiple PCR-based assays. Furthermore, primer pools were designed and successfully used to decrease the number of reactions needed for NA subtyping from 9 to 4. The quadruplicate primer-pool method is cost-saving, and was shown to be suitable for the NA subtyping of both cultured AIVs and uncultured AIV swab samples. The primers selected for this study showed excellent sensitivity and specificity in NA subtyping by RT-PCR, SYBR green-based Real-time PCR and Real-time RT-PCR methods. AIV RNA of 2 to 200 copies (varied by NA subtypes) could be detected by these reactions. No unspecific amplification was displayed when detecting RNAs of other avian infectious viruses such as Infectious bronchitis virus, Infectious bursal disease virus and Newcastle disease virus. In summary, this study introduced several sensitive and specific PCR-based assays for NA subtyping of AIVs and also validated again the effectiveness of the PrimerHunter tool for the design of subtyping primers. PMID:24312367

Epidemiology of human infections with highly pathogenic avian influenza A(H7N9) virus in Guangdong, 2016 to 2017.

PubMed

Kang, Min; Lau, Eric H Y; Guan, Wenda; Yang, Yuwei; Song, Tie; Cowling, Benjamin J; Wu, Jie; Peiris, Malik; He, Jianfeng; Mok, Chris Ka Pun

2017-07-06

We describe the epidemiology of highly pathogenic avian influenza (HPAI) A(H7N9) based on poultry market environmental surveillance and laboratory-confirmed human cases (n = 9) in Guangdong, China. We also compare the epidemiology between human cases of high- and low-pathogenic avian influenza A(H7N9) (n = 51) in Guangdong. Case fatality and severity were similar. Touching sick or dead poultry was the most important risk factor for HPAI A(H7N9) infections and should be highlighted for the control of future influenza A(H7N9) epidemics. This article is copyright of The Authors, 2017.

Replication of 2 subtypes of low-pathogenicity avian influenza virus of duck and gull origins in experimentally infected Mallard ducks.

PubMed

Daoust, P-Y; van de Bildt, M; van Riel, D; van Amerongen, G; Bestebroer, T; Vanderstichel, R; Fouchier, R A M; Kuiken, T

2013-05-01

Many subtypes of low-pathogenicity avian influenza (LPAI) virus circulate in wild bird reservoirs, but their prevalence may vary among species. We aimed to compare by real-time reverse-transcriptase polymerase chain reaction, virus isolation, histology, and immunohistochemistry the distribution and pathogenicity of 2 such subtypes of markedly different origins in Mallard ducks (Anas platyrhynchos): H2N3 isolated from a Mallard duck and H13N6 isolated from a Ring-billed Gull (Larus delawarensis). Following intratracheal and intraesophageal inoculation, neither virus caused detectable clinical signs, although H2N3 virus infection was associated with a significantly decreased body weight gain during the period of virus shedding. Both viruses replicated in the lungs and air sacs until approximately day 3 after inoculation and were associated with a locally extensive interstitial, exudative, and proliferative pneumonia. Subtype H2N3, but not subtype H13N6, went on to infect the epithelia of the intestinal mucosa and cloacal bursa, where it replicated without causing lesions until approximately day 5 after inoculation. Larger quantities of subtype H2N3 virus were detected in cloacal swabs than in pharyngeal swabs. The possible clinical significance of LPAI virus-associated pulmonary lesions and intestinal tract infection in ducks deserves further evaluation.

Infectivity and transmissibility of highly pathogenic avian influenza viruses in mallards

USDA-ARS?s Scientific Manuscript database

Wild aquatic birds have been associated with the intercontinental spread of H5 subtype highly pathogenic avian influenza (HPAI) viruses, but wild waterfowl have not been implicated in the spread of other HPAI viruses. In a previous study we demonstrated that many H5 and H7 HPAI viruses could infect...

Potency, efficacy, and antigenic mapping of H7 avian influenza virus vaccines against the 2012 H7N3 highly pathogenic avian influenza virus from Mexico.

PubMed

Spackman, Erica; Wan, Xiu-Feng; Kapczynski, Darrell; Xu, Yifei; Pantin-Jackwood, Mary; Suarez, David L; Swayne, David

2014-09-01

In the spring of 2012 an outbreak of H7N3 highly pathogenic (HP) avian influenza virus (AIV) occurred in poultry in Mexico. Vaccination was implemented as a control measure, along with increased biosecurity and surveillance. At that time there was no commercially available H7 AIV vaccine in North America; therefore, a recent H7N3 wild bird isolate of low pathogenicity from Mexico (A/cinnamon teal/Mexico/2817/2006 H7N3) was selected and utilized as the vaccine seed strain. In these studies, the potency and efficacy of this vaccine strain was evaluated in chickens against challenge with the 2012 Jalisco H7N3 HPAIV. Although vaccine doses of 256 and 102 hemagglutinating units (HAU) per bird decreased morbidity and mortality significantly compared to sham vaccinates, a dose of 512 HAU per bird was required to prevent mortality and morbidity completely. Additionally, the efficacy of 11 other H7 AIV vaccines and an antigenic map of hemagglutination inhibition assay data with all the vaccines and challenge viruses were evaluated, both to identify other potential vaccine strains and to characterize the relationship between genetic and antigenic distance with protection against this HPAIV. Several other isolates provided adequate protection against the 2012 Jalisco H7N3 lineage, but antigenic and genetic differences were not clear indicators of protection because the immunogenicity of the vaccine seed strain was also a critical factor.

Active Surveillance for Avian Influenza Virus, Egypt, 2010–2012

PubMed Central

Kandeil, Ahmed; El-Shesheny, Rabeh; Kayed, Ahmed S.; Gomaa, Mokhtar M.; Maatouq, Asmaa M.; Shehata, Mahmoud M.; Moatasim, Yassmin; Bagato, Ola; Cai, Zhipeng; Rubrum, Adam; Kutkat, Mohamed A.; McKenzie, Pamela P.; Webster, Robert G.; Webby, Richard J.; Ali, Mohamed A.

2014-01-01

Continuous circulation of influenza A(H5N1) virus among poultry in Egypt has created an epicenter in which the viruses evolve into newer subclades and continue to cause disease in humans. To detect influenza viruses in Egypt, since 2009 we have actively surveyed various regions and poultry production sectors. From August 2010 through January 2013, >11,000 swab samples were collected; 10% were positive by matrix gene reverse transcription PCR. During this period, subtype H9N2 viruses emerged, cocirculated with subtype H5N1 viruses, and frequently co-infected the same avian host. Genetic and antigenic analyses of viruses revealed that influenza A(H5N1) clade 2.2.1 viruses are dominant and that all subtype H9N2 viruses are G1-like. Cocirculation of different subtypes poses concern for potential reassortment. Avian influenza continues to threaten public and animal health in Egypt, and continuous surveillance for avian influenza virus is needed. PMID:24655395

H7N9 and H5N1 avian influenza suitability models for China: accounting for new poultry and live-poultry markets distribution data.

PubMed

Artois, Jean; Lai, Shengjie; Feng, Luzhao; Jiang, Hui; Zhou, Hang; Li, Xiangping; Dhingra, Madhur S; Linard, Catherine; Nicolas, Gaëlle; Xiao, Xiangming; Robinson, Timothy P; Yu, Hongjie; Gilbert, Marius

2017-01-01

In the last two decades, two important avian influenza viruses infecting humans emerged in China, the highly pathogenic avian influenza (HPAI) H5N1 virus in the late nineties, and the low pathogenic avian influenza (LPAI) H7N9 virus in 2013. China is home to the largest population of chickens (4.83 billion) and ducks (0.694 billion), representing, respectively 23.1 and 58.6% of the 2013 world stock, with a significant part of poultry sold through live-poultry markets potentially contributing to the spread of avian influenza viruses. Previous models have looked at factors associated with HPAI H5N1 in poultry and LPAI H7N9 in markets. However, these have not been studied and compared with a consistent set of predictor variables. Significant progress was recently made in the collection of poultry census and live-poultry market data, which are key potential factors in the distribution of both diseases. Here we compiled and reprocessed a new set of poultry census data and used these to analyse HPAI H5N1 and LPAI H7N9 distributions with boosted regression trees models. We found a limited impact of the improved poultry layers compared to models based on previous poultry census data, and a positive and previously unreported association between HPAI H5N1 outbreaks and the density of live-poultry markets. In addition, the models fitted for the HPAI H5N1 and LPAI H7N9 viruses predict a high risk of disease presence for the area around Shanghai and Hong Kong. The main difference in prediction between the two viruses concerned the suitability of HPAI H5N1 in north-China around the Yellow sea (outlined with Tianjin, Beijing, and Shenyang city) where LPAI H7N9 has not spread intensely.

Westward Spread of Highly Pathogenic Avian Influenza A(H7N9) Virus among Humans, China.

PubMed

Yang, Qiqi; Shi, Wei; Zhang, Lei; Xu, Yi; Xu, Jing; Li, Shen; Zhang, Junjun; Hu, Kan; Ma, Chaofeng; Zhao, Xiang; Li, Xiyan; Liu, Feng; Tong, Xin; Zhang, Guogang; Yu, Pengbo; Pybus, Oliver G; Tian, Huaiyu

2018-06-01

We report infection of humans with highly pathogenic avian influenza A(H7N9) virus in Shaanxi, China, in May 2017. We obtained complete genomes for samples from 5 patients and from live poultry markets or farms in 4 cities. Results indicate that H7N9 is spreading westward from southern and eastern China.

Impact of Mutations in the Hemagglutinin of H10N7 Viruses Isolated from Seals on Virus Replication in Avian and Human Cells.

PubMed

Dittrich, Anne; Scheibner, David; Salaheldin, Ahmed H; Veits, Jutta; Gischke, Marcel; Mettenleiter, Thomas C; Abdelwhab, Elsayed M

2018-02-14

Wild birds are the reservoir for low-pathogenic avian influenza viruses, which are frequently transmitted to domestic birds and occasionally to mammals. In 2014, an H10N7 virus caused severe mortality in harbor seals in northeastern Europe. Although the hemagglutinin (HA) of this virus was closely related to H10 of avian H10N4 virus, it possessed unique nonsynonymous mutations, particularly in the HA1 subunit in or adjacent to the receptor binding domain and proteolytic cleavage site. Here, the impact of these mutations on virus replication was studied in vitro. Using reverse genetics, an avian H10N4 virus was cloned, and nine recombinant viruses carrying one of eight unique mutations or the complete HA from the seal virus were rescued. Receptor binding affinity, replication in avian and mammalian cell cultures, cell-to-cell spread, and HA cleavability of these recombinant viruses were studied. Results show that wild-type recombinant H10N4 virus has high affinity to avian-type sialic acid receptors and no affinity to mammalian-type receptors. The H10N7 virus exhibits dual receptor binding affinity. Interestingly, Q220L (H10 numbering) in the rim of the receptor binding pocket increased the affinity of the H10N4 virus to mammal-type receptors and completely abolished the affinity to avian-type receptors. No remarkable differences in cell-to-cell spread or HA cleavability were observed. All viruses, including the wild-type H10N7 virus, replicated at higher levels in chicken cells than in human cells. These results indicate that H10N7 acquired adaptive mutations (e.g., Q220L) to enhance replication in mammals and retained replication efficiency in the original avian host.

Impact of Mutations in the Hemagglutinin of H10N7 Viruses Isolated from Seals on Virus Replication in Avian and Human Cells

PubMed Central

Dittrich, Anne; Scheibner, David; Salaheldin, Ahmed H.; Veits, Jutta; Gischke, Marcel

2018-01-01

Wild birds are the reservoir for low-pathogenic avian influenza viruses, which are frequently transmitted to domestic birds and occasionally to mammals. In 2014, an H10N7 virus caused severe mortality in harbor seals in northeastern Europe. Although the hemagglutinin (HA) of this virus was closely related to H10 of avian H10N4 virus, it possessed unique nonsynonymous mutations, particularly in the HA1 subunit in or adjacent to the receptor binding domain and proteolytic cleavage site. Here, the impact of these mutations on virus replication was studied in vitro. Using reverse genetics, an avian H10N4 virus was cloned, and nine recombinant viruses carrying one of eight unique mutations or the complete HA from the seal virus were rescued. Receptor binding affinity, replication in avian and mammalian cell cultures, cell-to-cell spread, and HA cleavability of these recombinant viruses were studied. Results show that wild-type recombinant H10N4 virus has high affinity to avian-type sialic acid receptors and no affinity to mammalian-type receptors. The H10N7 virus exhibits dual receptor binding affinity. Interestingly, Q220L (H10 numbering) in the rim of the receptor binding pocket increased the affinity of the H10N4 virus to mammal-type receptors and completely abolished the affinity to avian-type receptors. No remarkable differences in cell-to-cell spread or HA cleavability were observed. All viruses, including the wild-type H10N7 virus, replicated at higher levels in chicken cells than in human cells. These results indicate that H10N7 acquired adaptive mutations (e.g., Q220L) to enhance replication in mammals and retained replication efficiency in the original avian host. PMID:29443887

Complete genome sequence of a novel H9N2 subtype influenza virus FJG9 strain in China reveals a natural reassortant event.

PubMed

Xie, Qingmei; Yan, Zhuanqiang; Ji, Jun; Zhang, Huanmin; Liu, Jun; Sun, Yue; Li, Guangwei; Chen, Feng; Xue, Chunyi; Ma, Jingyun; Bee, Yingzuo

2012-09-01

A/chicken/FJ/G9/09 (FJ/G9) is an H9N2 subtype avian influenza virus (H9N2 AIV) strain causing high morbidity that was isolated from broilers in Fujian Province of China in 2009. FJ/G9 has been used as the vaccine strain against H9N2 AIV infection in Fujian Province of China. Here, we report the complete genome sequence of FJ/G9 with natural six-way reassortment, which is the most complex genotype strain in China and even in the world so far. The present findings will aid in understanding the complexity and diversity of H9N2 subtype avian influenza virus.

Phylogenetic analysis of H9N2 avian influenza viruses in Afghanistan (2016-2017).

PubMed

Hosseini, Hossein; Ghalyanchilangeroudi, Arash; Fallah Mehrabadi, Mohammad Hossein; Sediqian, Mohammad Saeed; Shayeganmehr, Arzhang; Ghafouri, Seyed Ali; Maghsoudloo, Hossein; Abdollahi, Hamed; Farahani, Reza Kh

2017-10-01

Avian influenza A virus (AIV) subtype H9N2 is the most prevalent subtype found in terrestrial poultry throughout Eurasia and has been isolated from poultry outbreaks worldwide. Tracheal tissue specimens from 100 commercial broiler flocks in Afghanistan were collected between 2016 and 2017. After real-time RT-PCR, AI-positive samples were further characterized. A part of the HA gene was amplified using RT-PCR and sequenced. The results of real-time RT-PCR showed that 40 percent of the flocks were AI positive. Phylogenetic studies showed that these H9N2 AIVs grouped within the Eurasian-lineage G1 AIVs and had a correlation with H9N2 AIV circulating in the poultry population of the neighboring countries over the past decade. Analysis of the amino acid sequence of HA revealed that the detected H9N2 viruses possessed molecular profiles suggestive of low pathogenicity and specificity for the avian-like SAα2,3 receptor, demonstrating their specificity for and adaptation to domestic poultry. The results of the current study provide great insights into H9N2 viruses circulating in Afghanistan's poultry industry and demonstrate the necessity of planning an applied policy aimed at controlling and managing H9N2 infection in Afghan poultry.

H7 avian influenza virus vaccines protect chickens against challenge with antigenically diverse isolates

USDA-ARS?s Scientific Manuscript database

Vaccination has been a critical tool in the control of some avian influenza viruses (AIV) and has been used routinely in Pakistan to help control sporadic outbreaks of highly pathogenic (HP) H7 AIV since 1995. During that time, several AIV isolates were utilized as inactivated vaccines with varying...

Quantifying Transmission of Highly Pathogenic and Low Pathogenicity H7N1 Avian Influenza in Turkeys

PubMed Central

Saenz, Roberto A.; Essen, Steve C.; Brookes, Sharon M.; Iqbal, Munir; Wood, James L. N.; Grenfell, Bryan T.; McCauley, John W.; Brown, Ian H.; Gog, Julia R.

2012-01-01

Outbreaks of avian influenza in poultry can be devastating, yet many of the basic epidemiological parameters have not been accurately characterised. In 1999–2000 in Northern Italy, outbreaks of H7N1 low pathogenicity avian influenza virus (LPAI) were followed by the emergence of H7N1 highly pathogenic avian influenza virus (HPAI). This study investigates the transmission dynamics in turkeys of representative HPAI and LPAI H7N1 virus strains from this outbreak in an experimental setting, allowing direct comparison of the two strains. The fitted transmission rates for the two strains are similar: 2.04 (1.5–2.7) per day for HPAI, 2.01 (1.6–2.5) per day for LPAI. However, the mean infectious period is far shorter for HPAI (1.47 (1.3–1.7) days) than for LPAI (7.65 (7.0–8.3) days), due to the rapid death of infected turkeys. Hence the basic reproductive ratio, is significantly lower for HPAI (3.01 (2.2–4.0)) than for LPAI (15.3 (11.8–19.7)). The comparison of transmission rates and are critically important in relation to understanding how HPAI might emerge from LPAI. Two competing hypotheses for how transmission rates vary with population size are tested by fitting competing models to experiments with differing numbers of turkeys. A model with frequency-dependent transmission gives a significantly better fit to experimental data than density-dependent transmission. This has important implications for extrapolating experimental results from relatively small numbers of birds to the commercial poultry flock size, and for how control, including vaccination, might scale with flock size. PMID:23028760

Limited antigenic diversity in contemporary H7 avian-origin influenza A viruses from North America

USDA-ARS?s Scientific Manuscript database

Subtype H7 avian–origin influenza A viruses (AIVs) have caused at least 500 confirmed human infections since 2003 and culling of >75 million birds in recent years. Understanding the antigenic diversity and genetic evolution of H7 AIVs is critical for developing effective strategies for disease prev...

Detection of influenza virus types A and B and type A subtypes (H1, H3, and H5) by multiplex polymerase chain reaction.

PubMed

Boonsuk, Pitirat; Payungporn, Sunchai; Chieochansin, Thaweesak; Samransamruajkit, Rujipat; Amonsin, Alongkorn; Songserm, Thaweesak; Chaisingh, Arunee; Chamnanpood, Pornchai; Chutinimitkul, Salin; Theamboonlers, Apiradee; Poovorawan, Yong

2008-07-01

Infections with influenza virus type A and B present serious public health problems on a global scale. However, only influenza A virus has been reported to cause fatal pandemic in many species. To provide suitable clinical management and prevent further virus transmission, efficient and effective clinical diagnosis is essential. Therefore, we developed multiplex PCR assays for detecting influenza types A and B and the subtypes of influenza A virus (H1, H3 and H5). Upon performing multiplex PCR assays with type-specific primer sets, the clearly distinguishable products representing influenza A and B virus were separated by agarose gel electrophoresis. In addition, the subtypes of influenza A virus (H1, H3 and H5), which are most common in humans, can be readily distinguished by PCR with subtype-specific primer sets, yielding PCR products of different sizes depending on which subtype has been amplified. This method was tested on 46 influenza virus positive specimens of avian and mammalian (dog and human) origins collected between 2006 and 2008. The sensitivity of this method, tested against known concentrations of each type and subtype specific plasmid, was established to detect 10(3) copies/microl. The method's specificity was determined by testing against other subtypes of influenza A virus (H2, H4 and H6-H15) and respiratory pathogens commonly found in humans. None of them could be amplified, thus excluding cross reactivity. In conclusion, the multiplex PCR assays developed are advantageous as to rapidity, specificity, and cost effectiveness.

Enzootic genotype S of H9N2 avian influenza viruses donates internal genes to emerging zoonotic influenza viruses in China.

PubMed

Gu, Min; Chen, Hongzhi; Li, Qunhui; Huang, Junqing; Zhao, Mingjun; Gu, Xiaobing; Jiang, Kaijun; Wang, Xiaoquan; Peng, Daxin; Liu, Xiufan

2014-12-05

Avian influenza viruses of subtype H9N2 are widely prevalent in poultry in many Asian countries, and the segmented nature of the viral genome results in multiple distinct genotypes via reassortment. In this study, genetic evolution of H9N2 viruses circulating in eastern China during 2007-2013 was analyzed. The results showed that the diversity of the gene constellations generated six distinct genotypes, in which a novel genotype (S) bearing the backbone of A/chicken/Shanghai/F/98-like viruses by acquiring A/quail/Hong Kong/G1/97-like polymerase basic subunit 2 and matrix genes has gradually established its ecological niche and been consistently prevalent in chicken flocks in eastern China since its first detection in 2007. Furthermore, genotype S possessed the peculiarity to donate most of its gene segments to other emerging influenza A viruses in China, including the novel reassortant highly pathogenic avian influenza H5N2, the 2013 novel H7N7, H7N9 and the latest reassortant H10N8 viruses, with potential threat to poultry industry and human health. Copyright © 2014 Elsevier B.V. All rights reserved.

H7N9 Highly Pathogenic Avian Influenza in the United States in 2017

USDA-ARS?s Scientific Manuscript database

In early March of 2017 an outbreak of highly pathogenic avian influenza H7N9 was reported from a broiler-breeder flock Tennessee. A second HPAI case was detected 2 weeks later. Subsequent active and passive surveillance identified several LPAI cases in Alabama, Georgia, Kentucky, and TN that was g...

The Potential of Avian H1N1 Influenza A Viruses to Replicate and Cause Disease in Mammalian Models

PubMed Central

Koçer, Zeynep A.; Krauss, Scott; Stallknecht, David E.; Rehg, Jerold E.; Webster, Robert G.

2012-01-01

H1N1 viruses in which all gene segments are of avian origin are the most frequent cause of influenza pandemics in humans; therefore, we examined the disease-causing potential of 31 avian H1N1 isolates of American lineage in DBA/2J mice. Thirty of 31 isolates were very virulent, causing respiratory tract infection; 22 of 31 resulted in fecal shedding; and 10 of 31 were as pathogenic as the pandemic 2009 H1N1 viruses. Preliminary studies in BALB/cJ mice and ferrets showed that 1 of 4 isolates tested was more pathogenic than the pandemic 2009 H1N1 viruses in BALB/cJ mice, and 1 of 2 strains transmitted both by direct and respiratory-droplet contact in ferrets. Preliminary studies of other avian subtypes (H2, H3, H4, H6, H10, H12) in DBA/2J mice showed lower pathogenicity than the avian H1N1 viruses. These findings suggest that avian H1N1 influenza viruses are unique among influenza A viruses in their potential to infect mammals. PMID:22848544

An overview of the characteristics of the novel avian influenza A H7N9 virus in humans

PubMed Central

Tan, Kei-Xian; Jacob, Sabrina A.; Chan, Kok-Gan; Lee, Learn-Han

2015-01-01

The novel avian influenza A H7N9 virus which caused the first human infection in Shanghai, China; was reported on the 31st of March 2013 before spreading rapidly to other Chinese provinces and municipal cities. This is the first time the low pathogenic avian influenza A virus has caused human infections and deaths; with cases of severe respiratory disease with pneumonia being reported. There were 440 confirmed cases with 122 fatalities by 16 May 2014; with a fatality risk of ∼28%. The median age of patients was 61 years with a male-to-female ratio of 2.4:1. The main source of infection was identified as exposure to poultry and there is so far no definitive evidence of sustained person-to-person transmission. The neuraminidase inhibitors, namely oseltamivir, zanamivir, and peramivir; have shown good efficacy in the management of the novel H7N9 virus. Treatment is recommended for all hospitalized patients, and for confirmed and probable outpatient cases; and should ideally be initiated within 48 h of the onset of illness for the best outcome. Phylogenetic analysis found that the novel H7N9 virus is avian in origin and evolved from multiple reassortments of at least four origins. Indeed the novel H7N9 virus acquired human adaptation via mutations in its eight RNA gene segments. Enhanced surveillance and effective global control are essential to prevent pandemic outbreaks of the novel H7N9 virus. PMID:25798131

Human infection of novel avian influenza A(H7N4) virus.

PubMed

Tong, Xue-Cheng; Weng, Shan-Shan; Xue, Feng; Wu, Xing; Xu, Tian-Min; Zhang, Wen-Hong

2018-06-10

Multiple reassortant strains of novel, highly pathogenic avian influenza A have recently emerged and spread over the world. Here we report on a 68-year-old woman in Jiangsu, China, with influenza A(H7N4) infection and associated illness, which strongly demonstrating the ability of the virus to spread from animals to humans and thus emphasizing the importance of continuous surveillance of the emerging viruses. Copyright © 2018. Published by Elsevier Ltd.

Age-specific and sex-specific morbidity and mortality from avian influenza A(H7N9).

PubMed

Dudley, Joseph P; Mackay, Ian M

2013-11-01

We used data on age and sex for 136 laboratory confirmed human A(H7N9) cases reported as of 11 August 2013 to compare age-specific and sex-specific patterns of morbidity and mortality from the avian influenza A(H7N9) virus with those of the avian influenza A(H5N1) virus. Human A(H7N9) cases exhibit high degrees of age and sex bias: mortality is heavily biased toward males >50 years, no deaths have been reported among individuals <25 years old, and relatively few cases documented among children or adolescents. The proportion of fatal cases (PFC) for human A(H7N9) cases as of 11 August 2013 was 32%, compared to a cumulative PFC for A(H5N1) of 83% in Indonesia and 36% in Egypt. Approximately 75% of cases of all A(H7N9) cases occurred among individuals >45 years old. Morbidity and mortality from A(H7N9) are lowest among individuals between 10 and 29 years, the age group which exhibits the highest cumulative morbidity and case fatality rates from A(H5N1). Although individuals <20 years old comprise nearly 50% of all human A(H5N1) cases, only 7% of all reported A(H7N9) cases and no deaths have been reported among individuals in this age group. Only 4% of A(H7N9) cases occurred among children<5 years old, and only one case from the 10 to 20 year age group. Age- and sex-related differences in morbidity and mortality from emerging zoonotic diseases can provide insights into ecological, economic, and cultural factors that may contribute to the emergence and proliferation of novel zoonotic diseases in human populations. Copyright © 2013 Elsevier B.V. All rights reserved.

Influenza A H5N1 and H7N9 in China: A spatial risk analysis

PubMed Central

Gardner, Lauren; MacIntyre, Raina; Sarkar, Sahotra

2017-01-01

Background Zoonotic avian influenza poses a major risk to China, and other parts of the world. H5N1 has remained endemic in China and globally for nearly two decades, and in 2013, a novel zoonotic influenza A subtype H7N9 emerged in China. This study aimed to improve upon our current understanding of the spreading mechanisms of H7N9 and H5N1 by generating spatial risk profiles for each of the two virus subtypes across mainland China. Methods and findings In this study, we (i) developed a refined data set of H5N1 and H7N9 locations with consideration of animal/animal environment case data, as well as spatial accuracy and precision; (ii) used this data set along with environmental variables to build species distribution models (SDMs) for each virus subtype in high resolution spatial units of 1km2 cells using Maxent; (iii) developed a risk modelling framework which integrated the results from the SDMs with human and chicken population variables, which was done to quantify the risk of zoonotic transmission; and (iv) identified areas at high risk of H5N1 and H7N9 transmission. We produced high performing SDMs (6 of 8 models with AUC > 0.9) for both H5N1 and H7N9. In all our SDMs, H7N9 consistently showed higher AUC results compared to H5N1, suggesting H7N9 suitability could be better explained by environmental variables. For both subtypes, high risk areas were primarily located in south-eastern China, with H5N1 distributions found to be more diffuse and extending more inland compared to H7N9. Conclusions We provide projections of our risk models to public health policy makers so that specific high risk areas can be targeted for control measures. We recommend comparing H5N1 and H7N9 prevalence rates and survivability in the natural environment to better understand the role of animal and environmental transmission in human infections. PMID:28376125

Genetic changes that accompanied shifts of low pathogenic avian influenza viruses toward higher pathogenicity in poultry

PubMed Central

Abdelwhab, El-Sayed M; Veits, Jutta; Mettenleiter, Thomas C

2013-01-01

Avian influenza viruses (AIV) of H5 and H7 subtypes exhibit two different pathotypes in poultry: infection with low pathogenic (LP) strains results in minimal, if any, health disturbances, whereas highly pathogenic (HP) strains cause severe morbidity and mortality. LPAIV of H5 and H7 subtypes can spontaneously mutate into HPAIV. Ten outbreaks caused by HPAIV are known to have been preceded by circulation of a predecessor LPAIV in poultry. Three of them were caused by H5N2 subtype and seven involved H7 subtype in combination with N1, N3, or N7. Here, we review those outbreaks and summarize the genetic changes which resulted in the transformation of LPAIV to HPAIV under natural conditions. Mutations that were found directly in those outbreaks are more likely to be linked to virulence, pathogenesis, and early adaptation of AIV. PMID:23863606

Avian influenza (H7N9) virus infection in Chinese tourist in Malaysia, 2014.

PubMed

William, Timothy; Thevarajah, Bharathan; Lee, Shiu Fee; Suleiman, Maria; Jeffree, Mohamad Saffree; Menon, Jayaram; Saat, Zainah; Thayan, Ravindran; Tambyah, Paul Anantharajah; Yeo, Tsin Wen

2015-01-01

Of the ≈400 cases of avian influenza (H7N9) diagnosed in China since 2003, the only travel-related cases have been in Hong Kong and Taiwan. Detection of a case in a Chinese tourist in Sabah, Malaysia, highlights the ease with which emerging viral respiratory infections can travel globally.

Evaluation of the Protective Efficacy of Poly I:C as an Adjuvant for H9N2 Subtype Avian Influenza Inactivated Vaccine and Its Mechanism of Action in Ducks.

PubMed

Zhang, Aiguo; Lai, Hanzhang; Xu, Jiahua; Huang, Wenke; Liu, Yufu; Zhao, Dawei; Chen, Ruiai

2017-01-01

Current commercial H9 avian influenza vaccines cannot provide satisfactory protective immunity against antigenic variant influenza viruses in ducks. Poly I:C, when used as an adjuvant, improves humoral and cellular immunity in many animals but has not been tested in ducks. In this study, we investigated the protective efficacy of Poly I:C as an adjuvant for an inactivated H9N2 Avian influenza vaccine in ducks. We found that an H9N2 vaccine administered with poly I:C (H9-PIC vaccine) induced a significantly more rapid response with higher anti-influenza antibody titers than those of the vaccine alone (H9 vaccine). Moreover, virus shedding was reduced in ducks immunized with the H9-PIC vaccine after challenge with an H9 subtype antigenic variant viruses. IFN-α, IFN-γ, IL-6 and MHC-II mRNA levels were all elevated in ducks receiving the H9-PIC vaccine. In addition, lower expression level of MHC-I may be a reason for inefficient protective ability against heterologous influenza viruses in H9-PIC vaccination of ducks. In conclusion, poly I:C adjuvant enhanced both humoral and cellular immune responses in ducks induced by immunization of inactivated H9N2 vaccine.

Evaluation of the Protective Efficacy of Poly I:C as an Adjuvant for H9N2 Subtype Avian Influenza Inactivated Vaccine and Its Mechanism of Action in Ducks

PubMed Central

Zhang, Aiguo; Lai, Hanzhang; Xu, Jiahua; Huang, Wenke; Liu, Yufu; Zhao, Dawei; Chen, Ruiai

2017-01-01

Current commercial H9 avian influenza vaccines cannot provide satisfactory protective immunity against antigenic variant influenza viruses in ducks. Poly I:C, when used as an adjuvant, improves humoral and cellular immunity in many animals but has not been tested in ducks. In this study, we investigated the protective efficacy of Poly I:C as an adjuvant for an inactivated H9N2 Avian influenza vaccine in ducks. We found that an H9N2 vaccine administered with poly I:C (H9-PIC vaccine) induced a significantly more rapid response with higher anti-influenza antibody titers than those of the vaccine alone (H9 vaccine). Moreover, virus shedding was reduced in ducks immunized with the H9-PIC vaccine after challenge with an H9 subtype antigenic variant viruses. IFN-α, IFN-γ, IL-6 and MHC-II mRNA levels were all elevated in ducks receiving the H9-PIC vaccine. In addition, lower expression level of MHC-I may be a reason for inefficient protective ability against heterologous influenza viruses in H9-PIC vaccination of ducks. In conclusion, poly I:C adjuvant enhanced both humoral and cellular immune responses in ducks induced by immunization of inactivated H9N2 vaccine. PMID:28135294

Highly pathogenic avian influenza virus (H5N1) isolated from whooper swans, Japan.

PubMed

Uchida, Yuko; Mase, Masaji; Yoneda, Kumiko; Kimura, Atsumu; Obara, Tsuyoshi; Kumagai, Seikou; Saito, Takehiko; Yamamoto, Yu; Nakamura, Kikuyasu; Tsukamoto, Kenji; Yamaguchi, Shigeo

2008-09-01

On April 21, 2008, four whooper swans were found dead at Lake Towada, Akita prefecture, Japan. Highly pathogenic avian influenza virus of the H5N1 subtype was isolated from specimens of the affected birds. The hemagglutinin (HA) gene of the isolate belongs to clade 2.3.2 in the HA phylogenetic tree.

Novel H7N2 and H5N6 Avian Influenza A Viruses in Sentinel Chickens: A Sentinel Chicken Surveillance Study.

PubMed

Zhao, Teng; Qian, Yan-Hua; Chen, Shan-Hui; Wang, Guo-Lin; Wu, Meng-Na; Huang, Yong; Ma, Guang-Yuan; Fang, Li-Qun; Gray, Gregory C; Lu, Bing; Tong, Yi-Gang; Ma, Mai-Juan; Cao, Wu-Chun

2016-01-01

In 2014, a sentinel chicken surveillance for avian influenza viruses was conducted in aquatic bird habitat near Wuxi City, Jiangsu Province, China. Two H7N2, one H5N6, and two H9N2 viruses were isolated. Sequence analysis revealed that the H7N2 virus is a novel reassortant of H7N9 and H9N2 viruses and H5N6 virus is a reassortant of H5N1 clade 2.3.4 and H6N6 viruses. Substitutions V186 and L226 (H3 numbering) in the hemagglutinin (HA) gene protein was found in two H7N2 viruses but not in the H5N6 virus. Two A138 and A160 mutations were identified in the HA gene protein of all three viruses but a P128 mutation was only observed in the H5N6 virus. A deletion of 3 and 11 amino acids in the neuraminidase stalk region was found in two H7N2 and H5N6 viruses, respectively. Moreover, a mutation of N31 in M2 protein was observed in both two H7N2 viruses. High similarity of these isolated viruses to viruses previously identified among poultry and humans, suggests that peridomestic aquatic birds may play a role in sustaining novel virus transmission. Therefore, continued surveillance is needed to monitor these avian influenza viruses in wild bird and domestic poultry that may pose a threat to poultry and human health.

Replication and Adaptive Mutations of Low Pathogenic Avian Influenza Viruses in Tracheal Organ Cultures of Different Avian Species

PubMed Central

Petersen, Henning; Matrosovich, Mikhail; Pleschka, Stephan; Rautenschlein, Silke

2012-01-01

Transmission of avian influenza viruses (AIV) between different avian species may require genome mutations that allow efficient virus replication in a new species and could increase virulence. To study the role of domestic poultry in the evolution of AIV we compared replication of low pathogenic (LP) AIV of subtypes H9N2, H7N7 and H6N8 in tracheal organ cultures (TOC) and primary embryo fibroblast cultures of chicken, turkey, Pekin duck and homing pigeon. Virus strain-dependent and avian species-related differences between LPAIV were observed in growth kinetics and induction of ciliostasis in TOC. In particular, our data demonstrate high susceptibility to LPAIV of turkey TOC contrasted with low susceptibility of homing pigeon TOC. Serial virus passages in the cells of heterologous host species resulted in adaptive mutations in the AIV genome, especially in the receptor-binding site and protease cleavage site of the hemagglutinin. Our data highlight differences in susceptibility of different birds to AIV viruses and emphasizes potential role of poultry in the emergence of new virus variants. PMID:22912693

Clinical Correlations of Transcriptional Profile in Patients Infected with Avian Influenza H7N9 Virus.

PubMed

Guan, Wenda; Wu, Nicholas C; Lee, Horace H Y; Li, Yimin; Jiang, Wenxin; Shen, Lihan; Wu, Douglas C; Chen, Rongchang; Zhong, Nanshan; Wilson, Ian A; Peiris, Malik; Yang, Zifeng; Mok, Chris K P

2018-05-28

Avian influenza A (H7N9) viruses emerged in China in 2013 and caused zoonotic disease associated with a case-fatality ratio of over 30%. Transcriptional profiles in peripheral blood reflect host responses and can help to elucidate disease pathogenesis. We correlated serial blood transcriptomic profiles of patients with avian influenza A (H7N9) virus infection and determined the biological significances from the analysis. We found that specific gene expression profiles in the blood were strongly correlated with the PaO2/FiO2 ratio and viral load in the lower respiratory tract (LRT). Cell cycle and leukocyte-related immunity were activated at the acute stage of the infection while T cell functions and various metabolic processes were associated with the recovery phase of the illness. A transition from systemic innate to adaptive immunity was found. We developed a novel approach for transcriptomic analysis to identify key host responses that were strongly correlated with specific clinical and virologic parameters in patients with H7N9 infection.

Design of new inhibitors for H5N1 avian influenza using a molecular dynamics simulation

NASA Astrophysics Data System (ADS)

Park, Jin Woo; Jo, Won Ho

2008-03-01

Recently, there has been a growing interest in the treatment of H5N1 avian influenza. One of the most widely used antiviral agents is oseltamivir. However, it has been reported that oseltamivir is not as effective against the neuraminidase subtype N1 as it is against subtypes N2 and N9. In our research we addressed this problem by designing new inhibitors and these altered inhibitor's binding affinities were calculated. In this study, we introduced chemical groups to the existing oseltamivir, so to fit into the newly discovered cavity in the subtype N1. When the binding strengths of the oseltamivir and the newly designed inhibitors for N1 were calculated to examine the drug efficiency through a molecular dynamics simulation, then compared with each other, it was found that one of the designed molecules exhibited a strong binding affinity, with more than twice the binding strength than that of oseltamivir. Since the aforementioned designed inhibitor appears to have the possibility for oral activity according to the criteria of human oral bioavailability, we propose that the inhibitor is a promising antiviral drug for H5N1 avian influenza.

Avian Influenza (H7N9) Virus Infection in Chinese Tourist in Malaysia, 2014

PubMed Central

William, Timothy; Thevarajah, Bharathan; Lee, Shiu Fee; Suleiman, Maria; Jeffree, Mohamad Saffree; Menon, Jayaram; Saat, Zainah; Thayan, Ravindran; Tambyah, Paul Anantharajah

2015-01-01

Of the ≈400 cases of avian influenza (H7N9) diagnosed in China since 2003, the only travel-related cases have been in Hong Kong and Taiwan. Detection of a case in a Chinese tourist in Sabah, Malaysia, highlights the ease with which emerging viral respiratory infections can travel globally. PMID:25531078

Multiple-locus variable-nucleotide tandem repeat subtype analysis implicates European starlings as biological vectors for Escherichia coli O157:H7 in Ohio, USA.

PubMed

Williams, M L; Pearl, D L; Lejeune, J T

2011-10-01

To provide molecular epidemiological evidence of avian transmission of Escherichia coli O157:H7 between dairy farms in Ohio, this study was designed to identify genetic relatedness between isolates originating from bovine faecal samples and intestinal contents of European starlings captured on these farms. During a three-year period (2007-2009), cattle (n = 9000) and starlings (n = 430) on 150 different dairy farms in northern Ohio were sampled for the presence of E. coli O157:H7. Isolates were subjected to multiple-locus variable-nucleotide tandem repeat analysis (MLVA). Distinct allelic groups were identified on most farms; however, isolates clustering into three MLVA groups originated from both cattle and birds on different farms. Sharing of indistinguishable epidemiologically linked E. coli O157 MLVA subtypes between starlings and cattle on different farms supports the hypothesis that these birds contribute to the transmission of E. coli O157:H7 between dairy farms. A continued need exists to identify and to improve preharvest measures for controlling E. coli O157:H7. Controlling wildlife intrusion, particularly European starlings, on livestock operations, may be an important strategy for reducing dissemination of E. coli O157:H7 between farms and thereby potentially decreasing the on-farm prevalence of E. coli O157:H7 and enhancing the safety of the food supply. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

Isolation and phylogenetic characterization of haemagglutinin and neuraminidase genes of H9N2 low pathogenicity avian influenza virus isolated from commercial layers in India.

PubMed

Gowthaman, Vasudevan; Singh, Shambu Dayal; Dhama, Kuldeep; Srinivasan, Palani; Saravanan, Sellappan; Murthy, Thippichettypalayam Ramasamy Gopala Krishna; Sukumar, Kuppanan; Mathapati, Basavaraj; Lebarbenchon, Camille; Malik, Yashpal Singh; Ramakrishnan, Muthannan Andavar

2016-12-01

Avian influenza is a highly infectious and dynamically evolving disease of birds causing high morbidity and mortality. It is caused by avian influenza virus (AIV) that belongs to the family Orthomyxoviridae. Two types of AIV have been described based on their pathogenicity viz. highly pathogenic avian influenza virus that causes severe disease with high mortality and low pathogenic avian influenza virus (LPAI) that generally causes asymptomatic infection or a mild disease. The H9N2 subtype is the widely circulated LPAI type in the world. The H9N2 subtype of was first reported from northern India in March 2003. However, systematical surveillance information for the evolution of H9N2 viruses in poultry flocks of Southern India is lacking. The present study reports the isolation and characterization of H9N2 isolates from the southern parts of the country during the period between May 2010 and September 2011. Out of the 30 poultry flocks investigated, six were found to be positive for HA activity. Further, all the six samples conformed as AIV. Partial nucleotide sequencing of the HA and NA genes revealed that all were belonging to the H9N2 subtype. Phylogenetically, the HA and NA genes of the H9N2 viruses from India clustered with those isolated from Bangladesh, Pakistan and the Middle East, although we were not able to conclude on their exact geographic origin.

Epidemiology of avian influenza in wild aquatic birds in a biosecurity hotspot, North Queensland, Australia.

PubMed

Hoque, Md Ahasanul; Burgess, Graham William; Cheam, Ai Lee; Skerratt, Lee Francis

2015-01-01

Migratory birds may introduce highly pathogenic H5N1 avian influenza from Southeast Asia into Australia via North Queensland, a key stopover along the East Asian-Australasian Flyway, with severe consequences for trade and human health. A 3-year repeated cross sectional study on the epidemiology of avian influenza in Australian nomadic wild aquatic birds was conducted in this potential biosecurity hotspot using molecular and serological techniques. Avian influenza virus subtypes H6 and H9 were commonly present in the studied population. It is likely that one of the H6 viruses was newly introduced through migratory birds confirming the perceived biosecurity risk. The matrix gene of another H6 virus was similar to the Australian H7 subtypes, which suggests the reassortment of a previously introduced H6 and local viruses. Similarly, a H9 subtype had a matrix gene similar to that found in Asian H9 viruses suggesting reassortment of viruses originated from Australia and Asia. Whilst H5N1 was not found, the serological study demonstrated a constant circulation of the H5 subtype in the sampled birds. The odds of being reactive for avian influenza viral antibodies were 13.1(95% CI: 5.9-28.9) for Pacific Black Ducks over Plumed Whistling Ducks, highlighting that some species of waterfowl pose a greater biosecurity risk. Antibody titres were slightly higher during warm wet compared with warm dry weather. Routine surveillance programmes should be established to monitor the introduction of avian influenza viruses from Asia and the interactions of the introduced viruses with resident viruses in order to better detect emerging pathogens in aquatic birds of North Queensland. Surveillance should be targeted towards highly susceptible species such as the Pacific Black Duck and carried out during favourable environmental conditions for viral transmission such as the wet season in northern Australia. Copyright © 2014 Elsevier B.V. All rights reserved.

Phylogenetic Analysis and Pathogenicity Assessment of Two Strains of Avian Influenza Virus Subtype H9N2 Isolated from Migratory Birds: High Homology of Internal Genes with Human H10N8 Virus.

PubMed

Ye, Ge; Liang, Chai Hong; Hua, Deng Guo; Song, Lei Yong; Xiang, Yang Guo; Guang, Chen; Lan, Chen Hua; Ping, Hua Yu

2016-01-01

Two human-infecting avian influenza viruses (AIVs), H7N9 and H10N8, have emerged in China, which further indicate that the H9N2 subtype of AIVs, as an internal gene donor, may have an important role in the generation of new viruses with cross-species transmissibility and pathogenicity. H9N2 viruses that contain such internal genes widely exist in poultry but are rarely reported in migratory birds. In this study, two strains of the H9N2 virus were isolated from fecal samples of migratory birds in 2014: one strain from Caizi Lake in Anhui Province and one from Chen Lake in Hubei Province of China. Nucleotide sequence analysis revealed high homology of all six internal genes of these two strains with the internal genes of the human H10N8 virus in Jiangxi Province, as well as with the human H7N9 virus. Phylogenetic analysis indicated a possible origin of these two strains from poultry in South China. Both of the two viruses tested could replicated in respiratory organs of infective mice without adaption, by both strains of the H9N2 AIVs from wild birds, suggesting their potential capacity for directly infecting mammals. Our findings indicate the existence of H9N2 viruses that contain internal genes highly homologous with human H10N8 or H7N9 viruses. Wild birds can contribute to the spread of the H9N2 virus that contains the "harmful" internal gene complex, leading to gene rearrangement with other influenza viruses and to the generation of new pathogenic viruses. Therefore, strengthening AIV surveillance in wild birds can promote an understanding of the presence and prevalence of viruses and provide scientific evidence for the prevention and control of AIVs and human-infecting AIVs.

An overview of the recent outbreaks of the avian-origin influenza A (H7N9) virus in the human.

PubMed

Tang, Ren-Bin; Chen, Hui-Lan

2013-05-01

Since the first human infection with influenza A (H7N9) viruses have been identified in Shanghai on March 31, 2013, the latest variant of the avian flu virus has spread across four Chinese provinces recently. Human infections with avian influenza are rare and this is the first time that human infection with a low pathogenic avian influenza A virus has been associated with fatal outcome. To date (May 5(th), 2013), China had reported 128 confirmed H7N9 infections in human, among 27 died. Most reported cases have severe respiratory illness resulting in severe pneumonia and in some cases have died. No evidence of sustained human-to -humans at this time, however, there is one family cluster with two confirmed cases for which human-to-human transmission cannot be ruled out. Recent evidence showed that the gene sequences of this novel H7N9 virus is primarily zoonotic and may be better adapted than other avian influenza viruses to infect human. Effective global infection control is urgently needed, and further surveillance and analyses should be undertaken to identify the source and mode of transmission of these viruses. Copyright © 2013. Published by Elsevier B.V.

The emergence of influenza A H7N9 in human beings 16 years after influenza A H5N1: a tale of two cities.

PubMed

To, Kelvin K W; Chan, Jasper F W; Chen, Honglin; Li, Lanjuan; Yuen, Kwok-Yung

2013-09-01

Infection with either influenza A H5N1 virus in 1997 or avian influenza A H7N9 virus in 2013 caused severe pneumonia that did not respond to typical or atypical antimicrobial treatment, and resulted in high mortality. Both viruses are reassortants with internal genes derived from avian influenza A H9N2 viruses that circulate in Asian poultry. Both viruses have genetic markers of mammalian adaptation in their haemagglutinin and polymerase PB2 subunits, which enhanced binding to human-type receptors and improved replication in mammals, respectively. Hong Kong (affected by H5N1 in 1997) and Shanghai (affected by H7N9 in 2013) are two rapidly flourishing cosmopolitan megacities that were increasing in human population and poultry consumption before the outbreaks. Both cities are located along the avian migratory route at the Pearl River delta and Yangtze River delta. Whether the widespread use of the H5N1 vaccine in east Asia-with suboptimum biosecurity measures in live poultry markets and farms-predisposed to the emergence of H7N9 or other virus subtypes needs further investigation. Why H7N9 seems to be more readily transmitted from poultry to people than H5N1 is still unclear. Copyright © 2013 Elsevier Ltd. All rights reserved.

Global concern regarding the fifth epidemic of human infection with avian influenza A (H7N9) virus in China.

PubMed

Shen, Yinzhong; Lu, Hongzhou

2017-03-22

Since the first outbreak of human infection with avian influenza A (H7N9) virus was identified in 2013, five seasonal outbreaks have occurred in China. The fifth outbreak started earlier than usual. A sudden increase in cases of human infection with avian influenza A (H7N9) virus has been reported in China since September 2016, and the number of cases reported in this season is exceeding that reported in previous seasons. This increase in the number of new cases of H7N9 infection has caused domestic and international concern. This paper summarizes the current prevalence of H7N9 in China and it also discusses measures that China has taken to control this outbreak. This paper also describes steps China must take in the future. This paper can serve as a reference for prevention and control of H7N9 outbreaks around the world.

The Detection of a Low Pathogenicity Avian Influenza Virus Subtype H9 Infection in a Turkey Breeder Flock in the United Kingdom.

PubMed

Reid, Scott M; Banks, Jill; Ceeraz, Vanessa; Seekings, Amanda; Howard, Wendy A; Puranik, Anita; Collins, Susan; Manvell, Ruth; Irvine, Richard M; Brown, Ian H

2016-05-01

In April 2013, an H9N2 low pathogenicity avian influenza (LPAI) virus was isolated in a turkey breeder farm in Eastern England comprising 4966 birds. Point-of-lay turkey breeding birds had been moved from a rearing site and within 5 days had shown rapid onset of clinical signs of dullness, coughing, and anorexia. Three houses were involved, two contained a total of 4727 turkey hens, and the third housed 239 male turkeys. Around 50% of the hens were affected, whereas the male turkeys demonstrated milder clinical signs. Bird morbidity rose from 10% to 90%, with an increase in mortality in both houses of turkey hens to 17 dead birds in one house and 27 birds in the second house by day 6. The birds were treated with an antibiotic but were not responsive. Postmortem investigation revealed air sacculitis but no infraorbital sinus swellings or sinusitis. Standard samples were collected, and influenza A was detected. H9 virus infection was confirmed in all three houses by detection and subtyping of hemagglutinating agents in embryonated specific-pathogen-free fowls' eggs, which were shown to be viruses of H9N2 subtype using neuraminidase inhibition tests and a suite of real-time reverse transcription PCR assays. LPAI virus pathotype was suggested by cleavage site sequencing, and an intravenous pathogenicity index of 0.00 confirmed that the virus was of low pathogenicity. Therefore, no official disease control measures were required, and despite the high morbidity, birds recovered and were kept in production. Neuraminidase sequence analysis revealed a deletion of 78 nucleotides in the stalk region, suggesting an adaptation of the virus to poultry. Hemagglutinin gene sequences of two of the isolates clustered with a group of H9 viruses containing other contemporary European H9 strains in the Y439/Korean-like group. The closest matches to the two isolates were A/turkey/Netherlands/11015452/11 (H9N2; 97.9-98% nucleotide identity) and A/mallard/Finland/Li13384/10 (H9N2; 97

Evolution, global spread, and pathogenicity of highly pathogenic avian influenza H5Nx clade 2.3.4.4

USDA-ARS?s Scientific Manuscript database

Novel subtypes of Eurasian-origin (Goose/Guangdong lineage) H5 highly pathogenic avian influenza (HPAI) viruses belonging to clade 2.3.4 such as H5N2, H5N5, H5N6, and H5N8 have been identified in China since 2008 and subsequently evolved into four genetically distinct groups (A – D) of clade 2.3.4.4...

A computationally optimized broadly reactive H5 hemagglutinin vaccine provides protection against homologous and heterologous H5N1 highly pathogenic avian influenza virus infection in chickens

USDA-ARS?s Scientific Manuscript database

Since its emergence in 1996 in China, H5N1 highly pathogenic avian influenza (HPAI) virus has continuously evolved into different genetic clades that have created challenges to maintaining antigenically relevant H5N1 vaccine seeds. Therefore, a universal (multi-hemagglutinin [HA] subtype) or more c...

Risk factors for avian influenza virus contamination of live poultry markets in Zhejiang, China during the 2015-2016 human influenza season.

PubMed

Wang, Xiaoxiao; Wang, Qimei; Cheng, Wei; Yu, Zhao; Ling, Feng; Mao, Haiyan; Chen, Enfu

2017-03-03

Live bird markets (LBMs), being a potential source of avian influenza virus, require effective environmental surveillance management. In our study, a total of 2865 environmental samples were collected from 292 LBMs during the 2015-2016 human influenza season from 10 cities in Zhejiang province, China. The samples were tested by real-time quantitative polymerase chain reaction (RT-PCR). Field investigations were carried out to investigate probable risk factors. Of the environmental samples, 1519 (53.0%) were contaminated by A subtype. The highest prevalence of the H9 subtype was 30.2%, and the frequencies of the H5 and H7 subtype were 9.3% and 17.3%, respectively. Hangzhou and Jinhua cities were contaminated more seriously than the others. The prevalence of H5/H7/H9 in drinking water samples was highest, at 50.9%, and chopping board swabs ranked second, at 49.3%. Duration of sales per day, types of live poultry, LBM location and the number of live poultry were the main risk factors for environmental contamination, according to logistic regression analysis. In conclusion, LBMs in Zhejiang were contaminated by avian influenza. Our study has provided clues for avian influenza prevention and control during the human influenza season, especially in areas where LBMs are not closed.

Influenza A virus subtypes in wild birds in North-Eastern Spain (Catalonia).

PubMed

Busquets, Núria; Alba, Anna; Napp, Sebastián; Sánchez, Azucena; Serrano, Erika; Rivas, Raquel; Núñez, José I; Majó, Natàlia

2010-04-01

Since the spread of H5N1 highly pathogenic avian influenza virus in 2005, many surveillance programmes have been initiated in poultry and wild birds worldwide. This study describes for the first time the detection of different subtypes of avian influenza viruses (AIV) in wild birds in the West Mediterranean area (Catalonia, North-Eastern Spain). During a 3-year period (from mid-2006 to mid-2009), 1374 birds from 16 different families were examined, and a total of 62 AIV were detected by means of a real-time reverse transcriptase PCR assay. AIV were more frequently detected in Anatidae, Phoenicopteridae, Rallidae and Laridae families. Of the 62 positive samples, 28 AIV could be isolated in embryonated eggs. All isolates were subtyped by haemagglutinin and neuraminidase inhibition techniques and 10 different haemagglutinins (HA) and 7 neuraminidases (NA) were found in 13 different subtype combinations. The most common combinations were H4N6 (22.2%) and H1N1 (18.5%). The HA and NA gene sequences of different AIV subtypes were compared and aligned with those available AIV strains from genome databases. Our studies on AIV phylogenetic analysis revealed that all AIV genes sequenced from wild birds in North-Eastern Spain clustered within Eurasian avian clades, including the sequences of H8, N4 and N5 genes analyzed for the first time in Europe. The results contribute to the understanding of AIV in the Mediterranean area and in Europe. Copyright 2009 Elsevier B.V. All rights reserved.

Evolution of highly pathogenic avian influenza H5N1 viruses in Egypt indicating progressive adaptation

USDA-ARS?s Scientific Manuscript database

Highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was first diagnosed in poultry in Egypt in 2006, and since then the disease became enzootic in poultry throughout the country affecting the poultry industry and village poultry as well as infecting humans. Vaccination has been used ...

A novel hemagglutinin protein produced in bacteria protects chickens against H5N1 highly pathogenic avian influenza viruses by inducing H5 subtype-specific neutralizing antibodies

PubMed Central

Sączyńska, Violetta; Romanik, Agnieszka; Florys, Katarzyna; Cecuda-Adamczewska, Violetta; Kęsik-Brodacka, Małgorzata; Śmietanka, Krzysztof; Olszewska, Monika; Domańska-Blicharz, Katarzyna; Minta, Zenon; Szewczyk, Bogusław; Płucienniczak, Grażyna; Płucienniczak, Andrzej

2017-01-01

The highly pathogenic (HP) H5N1 avian influenza viruses (AIVs) cause a mortality rate of up to 100% in infected chickens and pose a permanent pandemic threat. Attempts to obtain effective vaccines against H5N1 HPAIVs have focused on hemagglutinin (HA), an immunodominant viral antigen capable of eliciting neutralizing antibodies. The vast majority of vaccine projects have been performed using eukaryotic expression systems. In contrast, we used a bacterial expression system to produce vaccine HA protein (bacterial HA) according to our own design. The HA protein with the sequence of the H5N1 HPAIV strain was efficiently expressed in Escherichia coli, recovered in the form of inclusion bodies and refolded by dilution between two chromatographic purification steps. Antigenicity studies showed that the resulting antigen, referred to as rH5-E. coli, preserves conformational epitopes targeted by antibodies specific for H5-subtype HAs, inhibiting hemagglutination and/or neutralizing influenza viruses in vitro. The proper conformation of this protein and its ability to form functional oligomers were confirmed by a hemagglutination test. Consistent with the biochemical characteristics, prime-boost immunizations with adjuvanted rH5-E. coli protected 100% and 70% of specific pathogen-free, layer-type chickens against challenge with homologous and heterologous H5N1 HPAIVs, respectively. The observed protection was related to the positivity in the FluAC H5 test (IDVet) but not to hemagglutination-inhibiting antibody titers. Due to full protection, the effective contact transmission of the homologous challenge virus did not occur. Survivors from both challenges did not or only transiently shed the viruses, as established by viral RNA detection in oropharyngeal and cloacal swabs. Our results demonstrate that vaccination with rH5-E. coli could confer control of H5N1 HPAIV infection and transmission rates in chicken flocks, accompanied by reduced virus shedding. Moreover, the role of

Digital genotyping of avian influenza viruses of H7 subtype detected in central Europe in 2007-2011.

PubMed

Nagy, Alexander; Cerníková, Lenka; Křivda, Vlastimil; Horníčková, Jitka

2012-05-01

The objective of our study was to provide a genotype analysis of H7N7 and H7N9 influenza A viruses (IAV) and infer their relationships to co-circulating non-H7 IAV genomes. The H7N7 strains were collected in central Europe (Hungary-1, Czech Republic-1, Slovenia-1 and Poland-4) and the H7N9 in the Czech Republic and Spain between 2007 and 2011. Hand in hand with this effort, a novel IAV genotype visualization approach called digital genotyping was developed. This approach relies on phylogenetic data summarization and transformation into a pixel array called a segment identity matrix. The digital genotyping revealed a complicated genetic interplay between the H7 and co-circulating non-H7 IAV genotypes. At the H7 IAV level the most obvious relationships were observed between one Polish H7N7/446/09 and Czech H7N7/11 viruses which, despite the special and temporal distance of 800 km and 15 months, retained at least 6/8 genome segments. Close relationships were also observed between the Czech H7N9, Polish and Slovenian H7N7 on one hand and Hungarian and Slovenian H7N7 isolates on the other. In addition the former genomes exhibited close interplays with the Czech H6N2/09 and H11N9/10-like viruses. The Czech and Spanish H7N9 genomes were completely different and 6/8 of the Czech H7N9-like segments were traced to either the Czech H3N8/07, H11N9/09 and Polish H7N7/09-like viruses. The results of digital genotyping correlated with the previous observations obtained on the Polish H7N7 isolates. As was demonstrated, the digital genotyping provides a well-arranged and easily interpretable output and may serve as an alternative genotyping tool useful for handling and analysing even a large panel of IAV genomes. Copyright © 2012 Elsevier B.V. All rights reserved.

The significance of avian influenza virus mouse-adaptation and its application in characterizing the efficacy of new vaccines and therapeutic agents

PubMed Central

2017-01-01

Due to the increased frequency of interspecies transmission of avian influenza viruses, studies designed to identify the molecular determinants that could lead to an expansion of the host range have been increased. A variety of mouse-based mammalian-adaptation studies of avian influenza viruses have provided insight into the genetic alterations of various avian influenza subtypes that may contribute to the generation of a pandemic virus. To date, the studies have focused on avian influenza subtypes H5, H6, H7, H9, and H10 which have recently caused human infection. Although mice cannot fully reflect the course of human infection with avian influenza, these mouse studies can be a useful method for investigating potential mammalian adaptive markers against newly emerging avian influenza viruses. In addition, due to the lack of appropriate vaccines against the diverse emerging influenza viruses, the generation of mouse-adapted lethal variants could contribute to the development of effective vaccines or therapeutic agents. Within this review, we will summarize studies that have demonstrated adaptations of avian influenza viruses that result in an altered pathogenicity in mice which may suggest the potential application of mouse-lethal strains in the development of influenza vaccines and/or therapeutics in preclinical studies. PMID:28775972

Efficacy of inactivated influenza vaccines for protection of poultry against the H7N9 low pathogenic avian influenza virus isolated in China during 2013

USDA-ARS?s Scientific Manuscript database

The recent outbreak in China of avian influenza (AI) H7N9 in birds and humans underscores the interspecies movement of these viruses. Interestingly, the genetic composition of these H7N9 viruses appears to be solely of avian origin and of low pathogenicity in birds. Although few isolations of these ...

Mapping the risk of avian influenza in wild birds in the US

Treesearch

Trevon L. Fuller; Sassan S. Saatchi; Emily E. Curd; Erin Toffelmier; Henri A. Thomassen; Wolfgang Buermann; David F. DeSante; Mark P. Nott; James F. Saracco; C. J. Ralph; John D. Alexander; John P. Pollinger; Thomas B. Smith.

2010-01-01

Avian influenza virus (AIV) is an important public health issue because pandemic influenza viruses in people have contained genes from viruses that infect birds. The H5 and H7 AIV subtypes have periodically mutated from low pathogenicity to high pathogenicity form. Analysis of the geographic distribution of AIV can identify areas where reassortment events might occur...

High pathogenicity avian influenza outbreaks since 2008 except multi-continental panzootic of H5 Goose/Guangdong-lineage viruses

USDA-ARS?s Scientific Manuscript database

Since 2008, seven countries from five continents have experienced highly pathogenic avian influenza (HPAI) outbreaks in poultry due to viruses unrelated to H5 Goose/Guangdong lineage viruses. These have covered a range of virus subtypes and affected different production species from chickens to ost...

Genetics, Receptor Binding Property, and Transmissibility in Mammals of Naturally Isolated H9N2 Avian Influenza Viruses

PubMed Central

Deng, Guohua; Zhang, Qianyi; Wang, Jinliang; He, Xijun; Wang, Kaicheng; Chen, Jiming; Li, Yuanyuan; Fan, Jun; Kong, Huiui; Gu, Chunyang; Guan, Yuantao; Suzuki, Yasuo; Kawaoka, Yoshihiro; Liu, Liling; Jiang, Yongping; Tian, Guobin; Li, Yanbing; Bu, Zhigao; Chen, Hualan

2014-01-01

H9N2 subtype influenza viruses have been detected in different species of wild birds and domestic poultry in many countries for several decades. Because these viruses are of low pathogenicity in poultry, their eradication is not a priority for animal disease control in many countries, which has allowed them to continue to evolve and spread. Here, we characterized the genetic variation, receptor-binding specificity, replication capability, and transmission in mammals of a series of H9N2 influenza viruses that were detected in live poultry markets in southern China between 2009 and 2013. Thirty-five viruses represented 17 genotypes on the basis of genomic diversity, and one specific “internal-gene-combination” predominated among the H9N2 viruses. This gene combination was also present in the H7N9 and H10N8 viruses that have infected humans in China. All of the 35 viruses preferentially bound to the human-like receptor, although two also retained the ability to bind to the avian-like receptor. Six of nine viruses tested were transmissible in ferrets by respiratory droplet; two were highly transmissible. Some H9N2 viruses readily acquired the 627K or 701N mutation in their PB2 gene upon infection of ferrets, further enhancing their virulence and transmission in mammals. Our study indicates that the widespread dissemination of H9N2 viruses poses a threat to human health not only because of the potential of these viruses to cause an influenza pandemic, but also because they can function as “vehicles” to deliver different subtypes of influenza viruses from avian species to humans. PMID:25411973

Development of a multiplex probe combination-based one-step real-time reverse transcription-PCR for NA subtype typing of avian influenza virus.

PubMed

Sun, Zhihao; Qin, Tao; Meng, Feifei; Chen, Sujuan; Peng, Daxin; Liu, Xiufan

2017-10-18

Nine influenza virus neuraminidase (NA) subtypes have been identified in poultry and wild birds. Few methods are available for rapid and simple NA subtyping. Here we developed a multiplex probe combination-based one-step real-time reverse transcriptase PCR (rRT-PCR) to detect nine avian influenza virus NA subtypes. Nine primer-probe pairs were assigned to three groups based on the different fluorescent dyes of the probes (FAM, HEX, or Texas Red). Each probe detected only one NA subtype, without cross reactivity. The detection limit was less than 100 EID 50 or 100 copies of cDNA per reaction. Data obtained using this method with allantoic fluid samples isolated from live bird markets and H9N2-infected chickens correlated well with data obtained using virus isolation and sequencing, but was more sensitive. This new method provides a specific and sensitive alternative to conventional NA-subtyping methods.

Two genetically diverse H7N7 avian influenza viruses isolated from migratory birds in central China.

PubMed

Liu, Haizhou; Xiong, Chaochao; Chen, Jing; Chen, Guang; Zhang, Jun; Li, Yong; Xiong, Yanping; Wang, Runkun; Cao, Ying; Chen, Quanjiao; Liu, Di; Wang, Hanzhong; Chen, Jianjun

2018-04-11

After the emergence of H7N9 avian influenza viruses (AIV) in early 2013 in China, active surveillance of AIVs in migratory birds was undertaken, and two H7N7 strains were subsequently recovered from the fresh droppings of migratory birds; the strains were from different hosts and sampling sites. Phylogenetic and sequence similarity network analyses indicated that several genes of the two H7N7 viruses were closely related to those in AIVs circulating in domestic poultry, although different gene segments were implicated in the two isolates. This strongly suggested that genes from viruses infecting migratory birds have been introduced into poultry-infecting strains. A Bayesian phylogenetic reconstruction of all eight segments implied that multiple reassortments have occurred in the evolution of these viruses, particularly during late 2011 and early 2014. Antigenic analysis using a hemagglutination inhibition test showed that the two H7N7 viruses were moderately cross-reactive with H7N9-specific anti-serum. The ability of the two H7N7 viruses to remain infectious under various pH and temperature conditions was evaluated, and the viruses persisted the longest at near-neutral pH and in cold temperatures. Animal infection experiments showed that the viruses were avirulent to mice and could not be recovered from any organs. Our results indicate that low pathogenic, divergent H7N7 viruses circulate within the East Asian-Australasian flyway. Virus dispersal between migratory birds and domestic poultry may increase the risk of the emergence of novel unprecedented strains.

Establishment of the cross-clade antigen detection system for H5 subtype influenza viruses using peptide monoclonal antibodies specific for influenza virus H5 hemagglutinin.

PubMed

Takahashi, Hitoshi; Nagata, Shiho; Odagiri, Takato; Kageyama, Tsutomu

2018-04-15

The H5 subtype of highly pathogenic avian influenza (H5 HPAI) viruses is a threat to both animal and human public health and has the potential to cause a serious future pandemic in humans. Thus, specific and rapid detection of H5 HPAI viruses is required for infection control in humans. To develop a simple and rapid diagnostic system to detect H5 HPAI viruses with high specificity and sensitivity, we attempted to prepare monoclonal antibodies (mAbs) that specifically recognize linear epitopes in hemagglutinin (HA) of H5 subtype viruses. Nine mAb clones were obtained from mice immunized with a synthetic partial peptide of H5 HA molecules conserved among various H5 HPAI viruses. The antigen-capture enzyme-linked immunosorbent assay using the most suitable combination of these mAbs, which bound specifically to lysed H5 HA under an optimized detergent condition, was specific for H5 viruses and could broadly detect H5 viruses in multiple different clades. Taken together, these peptide mAbs, which recognize linear epitopes in a highly conserved region of H5 HA, may be useful for specific and highly sensitive detection of H5 HPAI viruses and can help in the rapid diagnosis of human, avian, and animal H5 virus infections. Copyright © 2018 Elsevier Inc. All rights reserved.

Genetic characterization of avian metapneumovirus subtype C isolated from pheasants in a live bird market.

PubMed

Lee, Eun ho; Song, Min-Suk; Shin, Jin-Young; Lee, Young-Min; Kim, Chul-Joong; Lee, Young Sik; Kim, Hyunggee; Choi, Young Ki

2007-09-01

Complete nucleotide sequences of two avian metapneumoviruses (aMPV), designated PL-1 and PL-2, were isolated from pheasants, revealing novel sequences of the first aMPV to be fully sequenced in Korea. The complete genome of both PL-1 and PL-2 was composed of 13,170 nucleotides. Phylogenetic analysis revealed that PL-1 belonged to aMPV subtype C, sharing higher homology in deduced amino acid sequence identities with hMPV, rather than with aMPV subtypes A and B. Replication of PL-1 in experimentally re-infected pheasants was confirmed by reverse transcription (RT)-polymerase chain reaction (PCR). Chickens and mice were experimentally inoculated with PL-1 to test the replication potential of PL-1 in other species. Although one specimen from the nasal turbinates of an inoculated chicken showed a slight trace of viral replication at 3 days post-infection (dpi), all of the infected mice were negative for aMPV by RT-PCR throughout the experiment, suggesting that PL-1 does not readily infect mammals. This is the first report of the isolation and complete genomic sequence of aMPV subtype C originating from pheasants.

Novel H7N9 influenza virus shows low infectious dose, high growth rate, and efficient contact transmission in the guinea pig model.

PubMed

Gabbard, Jon D; Dlugolenski, Daniel; Van Riel, Debby; Marshall, Nicolle; Galloway, Summer E; Howerth, Elizabeth W; Campbell, Patricia J; Jones, Cheryl; Johnson, Scott; Byrd-Leotis, Lauren; Steinhauer, David A; Kuiken, Thijs; Tompkins, S Mark; Tripp, Ralph; Lowen, Anice C; Steel, John

2014-02-01

The zoonotic outbreak of H7N9 subtype avian influenza virus that occurred in eastern China in the spring of 2013 resulted in 135 confirmed human cases, 44 of which were lethal. Sequencing of the viral genome revealed a number of molecular signatures associated with virulence or transmission in mammals. We report here that, in the guinea pig model, a human isolate of novel H7N9 influenza virus, A/Anhui/1/2013 (An/13), is highly dissimilar to an H7N1 avian isolate and instead behaves similarly to a human seasonal strain in several respects. An/13 was found to have a low 50% infectious dose, grow to high titers in the upper respiratory tract, and transmit efficiently among cocaged guinea pigs. The pH of fusion of the hemagglutinin (HA) and the binding of virus to fixed guinea pig tissues were also examined. The An/13 HA displayed a relatively elevated pH of fusion characteristic of many avian strains, and An/13 resembled avian viruses in terms of attachment to tissues. One important difference was seen between An/13 and both the H3N2 human and the H7N1 avian viruses: when inoculated intranasally at a high dose, only the An/13 virus led to productive infection of the lower respiratory tract of guinea pigs. In sum, An/13 was found to retain fusion and attachment properties of an avian influenza virus but displayed robust growth and contact transmission in the guinea pig model atypical of avian strains and indicative of mammalian adaptation.

Novel H7N9 Influenza Virus Shows Low Infectious Dose, High Growth Rate, and Efficient Contact Transmission in the Guinea Pig Model

PubMed Central

Gabbard, Jon D.; Dlugolenski, Daniel; Van Riel, Debby; Marshall, Nicolle; Galloway, Summer E.; Howerth, Elizabeth W.; Campbell, Patricia J.; Jones, Cheryl; Johnson, Scott; Byrd-Leotis, Lauren; Steinhauer, David A.; Kuiken, Thijs; Tompkins, S. Mark; Tripp, Ralph; Lowen, Anice C.

2014-01-01

The zoonotic outbreak of H7N9 subtype avian influenza virus that occurred in eastern China in the spring of 2013 resulted in 135 confirmed human cases, 44 of which were lethal. Sequencing of the viral genome revealed a number of molecular signatures associated with virulence or transmission in mammals. We report here that, in the guinea pig model, a human isolate of novel H7N9 influenza virus, A/Anhui/1/2013 (An/13), is highly dissimilar to an H7N1 avian isolate and instead behaves similarly to a human seasonal strain in several respects. An/13 was found to have a low 50% infectious dose, grow to high titers in the upper respiratory tract, and transmit efficiently among cocaged guinea pigs. The pH of fusion of the hemagglutinin (HA) and the binding of virus to fixed guinea pig tissues were also examined. The An/13 HA displayed a relatively elevated pH of fusion characteristic of many avian strains, and An/13 resembled avian viruses in terms of attachment to tissues. One important difference was seen between An/13 and both the H3N2 human and the H7N1 avian viruses: when inoculated intranasally at a high dose, only the An/13 virus led to productive infection of the lower respiratory tract of guinea pigs. In sum, An/13 was found to retain fusion and attachment properties of an avian influenza virus but displayed robust growth and contact transmission in the guinea pig model atypical of avian strains and indicative of mammalian adaptation. PMID:24227867

Identification of combinatorial host-specific signatures with a potential to affect host adaptation in influenza A H1N1 and H3N2 subtypes.

PubMed

Khaliq, Zeeshan; Leijon, Mikael; Belák, Sándor; Komorowski, Jan

2016-07-29

The underlying strategies used by influenza A viruses (IAVs) to adapt to new hosts while crossing the species barrier are complex and yet to be understood completely. Several studies have been published identifying singular genomic signatures that indicate such a host switch. The complexity of the problem suggested that in addition to the singular signatures, there might be a combinatorial use of such genomic features, in nature, defining adaptation to hosts. We used computational rule-based modeling to identify combinatorial sets of interacting amino acid (aa) residues in 12 proteins of IAVs of H1N1 and H3N2 subtypes. We built highly accurate rule-based models for each protein that could differentiate between viral aa sequences coming from avian and human hosts. We found 68 host-specific combinations of aa residues, potentially associated to host adaptation on HA, M1, M2, NP, NS1, NEP, PA, PA-X, PB1 and PB2 proteins of the H1N1 subtype and 24 on M1, M2, NEP, PB1 and PB2 proteins of the H3N2 subtypes. In addition to these combinations, we found 132 novel singular aa signatures distributed among all proteins, including the newly discovered PA-X protein, of both subtypes. We showed that HA, NA, NP, NS1, NEP, PA-X and PA proteins of the H1N1 subtype carry H1N1-specific and HA, NA, PA-X, PA, PB1-F2 and PB1 of the H3N2 subtype carry H3N2-specific signatures. M1, M2, PB1-F2, PB1 and PB2 of H1N1 subtype, in addition to H1N1 signatures, also carry H3N2 signatures. Similarly M1, M2, NP, NS1, NEP and PB2 of H3N2 subtype were shown to carry both H3N2 and H1N1 host-specific signatures (HSSs). To sum it up, we computationally constructed simple IF-THEN rule-based models that could distinguish between aa sequences of avian and human IAVs. From the rules we identified HSSs having a potential to affect the adaptation to specific hosts. The identification of combinatorial HSSs suggests that the process of adaptation of IAVs to a new host is more complex than previously suggested

Characterization of an Avian Influenza Virus H9N2 Strain Isolated from Dove in Southern China.

PubMed

Li, Dan; Li, ZhengTing; Xie, Zhixun; Li, Meng; Xie, Zhiqin; Liu, Jiabo; Xie, Liji; Deng, Xianwen; Luo, Sisi

2018-05-03

We report here the complete genome sequence of strain H9N2, an avian influenza virus (AIV) isolated from dove in Guangxi, China. Phylogenetic analysis showed that it was a novel reassortant AIV derived from chicken, duck, and wild bird. This finding provides useful information for understanding the H9N2 subtype of AIV circulating in southern China. Copyright © 2018 Li et al.

Avian Influenza in Wild Birds, Central Coast of Peru

PubMed Central

Blazes, David L.; Icochea, Eliana; Gonzalez, Rosa I.; Kochel, Tadeusz; Tinoco, Yeny; Sovero, Merly M.; Lindstrom, Stephen; Shu, Bo; Klimov, Alexander; Gonzalez, Armando E.; Montgomery, Joel M.

2009-01-01

To determine genotypes of avian influenza virus circulating among wild birds in South America, we collected and tested environmental fecal samples from birds along the coast of Peru, June 2006–December 2007. The 9 isolates recovered represented 4 low-pathogenicity avian influenza strains: subtypes H3N8, H4N5, H10N9, and H13N2. PMID:19523296

Long-Term Effect of Serial Infections with H13 and H16 Low-Pathogenic Avian Influenza Viruses in Black-Headed Gulls

PubMed Central

Verhagen, Josanne H.; van Amerongen, Geert; van de Bildt, Marco; Majoor, Frank; Fouchier, Ron A. M.

2015-01-01

ABSTRACT Infections of domestic and wild birds with low-pathogenic avian influenza viruses (LPAIVs) have been associated with protective immunity to subsequent infection. However, the degree and duration of immunity in wild birds from previous LPAIV infection, by the same or a different subtype, are poorly understood. Therefore, we inoculated H13N2 (A/black-headed gull/Netherlands/7/2009) and H16N3 (A/black-headed gull/Netherlands/26/2009) LPAIVs into black-headed gulls (Chroicocephalus ridibundus), their natural host species, and measured the long-term immune response and protection against one or two reinfections over a period of >1 year. This is the typical interval between LPAIV epizootics in wild birds. Reinfection with the same virus resulted in progressively less virus excretion, with complete abrogation of virus excretion after two infections for H13 but not H16. However, reinfection with the other virus affected neither the level nor duration of virus excretion. Virus excretion by immunologically naive birds did not differ in total levels of excreted H13 or H16 virus between first- and second-year birds, but the duration of H13 excretion was shorter for second-year birds. Furthermore, serum antibody levels did not correlate with protection against LPAIV infection. LPAIV-infected gulls showed no clinical signs of disease. These results imply that the epidemiological cycles of H13 and H16 in black-headed gulls are relatively independent from each other and depend mainly on infection of first-year birds. IMPORTANCE Low-pathogenic avian influenza viruses (LPAIVs) circulate mainly in wild water birds but are occasionally transmitted to other species, including humans, where they cause subclinical to fatal disease. To date, the effect of LPAIV-specific immunity on the epidemiology of LPAIV in wild birds is poorly understood. In this study, we investigated the effect of H13 and H16 LPAIV infection in black-headed gulls on susceptibility and virus excretion of

Genetic characterization of natural reassortant H4 subtype avian influenza viruses isolated from domestic ducks in Zhejiang province in China from 2013 to 2014.

PubMed

Wu, Haibo; Peng, Xiuming; Peng, Xiaorong; Cheng, Linfang; Lu, Xiangyun; Jin, Changzhong; Xie, Tiansheng; Yao, Hangping; Wu, Nanping

2015-12-01

The H4 subtype of the influenza virus was first isolated in 1999 from pigs with pneumonia in Canada. H4 avian influenza viruses (AIVs) are able to cross the species barrier to infect humans. In order to better understand the genetic relationships between H4 AIV strains circulating in Eastern China and other AIV strains from Asia, a survey of domestic ducks in live poultry markets was undertaken in Zhejiang province from 2013 to 2014. In this study, 23 H4N2 (n = 14) and H4N6 (n = 9) strains were isolated from domestic ducks, and all eight gene segments of these strains were sequenced and compared to reference AIV strains available in GenBank. The isolated strains clustered primarily within the Eurasian lineage. No mutations associated with adaption to mammalian hosts or drug resistance was observed. The H4 reassortant strains were found to be of low pathogenicity in mice and able to replicate in the lung of the mice without prior adaptation. Continued surveillance is required, given the important role of domestic ducks in reassortment events leading to new AIVs.

Avian Influenza: A growing threat to Africa

USDA-ARS?s Scientific Manuscript database

The H9N2 low pathogenic avian influenza (LPAI) is probably the most widespread avian influenza subtype in poultry around the world being endemic in a large part of Asia, the Middle East, Northern Africa, and in Germany. Currently, there is no standardized clade system to describe the antigenic vari...

The T160A hemagglutinin substitution affects not only receptor binding property but also transmissibility of H5N1 clade 2.3.4 avian influenza virus in guinea pigs.

PubMed

Gu, Min; Li, Qunhui; Gao, Ruyi; He, Dongchang; Xu, Yunpeng; Xu, Haixu; Xu, Lijun; Wang, Xiaoquan; Hu, Jiao; Liu, Xiaowen; Hu, Shunlin; Peng, Daxin; Jiao, Xinan; Liu, Xiufan

2017-02-06

We generated and characterized site-directed HA mutants on the genetic backbone of H5N1 clade 2.3.4 virus preferentially binding to α-2,3 receptors in order to identify the key determinants in hemagglutinin rendering the dual affinity to both α-2,3 (avian-type) and α-2,6 (human-type) linked sialic acid receptors of the current clade 2.3.4.4 H5NX subtype avian influenza reassortants. The results show that the T160A substitution resulted in the loss of a glycosylation site at 158N and led not only to enhanced binding specificity for human-type receptors but also transmissibility among guinea pigs, which could be considered as an important molecular marker for assessing pandemic potential of H5 subtype avian influenza isolates.

Clinical and Pathologic Characterization of an Outbreak of Highly Pathogenic Avian Influenza H7N8 in Commercial Turkeys in Southern Indiana.

PubMed

Burcham, Grant N; Ramos-Vara, José A; Murphy, Duane A

2017-09-01

Highly pathogenic avian influenza (HPAI) is a systemic lethal disease of poultry caused by several subtypes of influenza A virus and classified on the basis of serologic reactions to hemagglutinin and neuraminidase surface glycoproteins. In January 2016, a novel subtype of HPAI-H7N8-was diagnosed in a commercial turkey (Meleagris gallopavo) flock in southern Indiana. Clinical signs and history included increased mortality, dyspnea, head tremors, recumbency, and somnolent or unaware birds. Postmortem examination of six recently dead birds showed red-tinged mucous in the choana and trachea and marked pulmonary edema. Histologic lesions in the brain included severe, multifocal lymphohistiocytic meningoencephalitis with foci of malacia, neuronal necrosis, and neuronophagia. All anatomic locations of the brain were affected, although histologic changes in the cerebellum were considered mild. Other histologic lesions included pulmonary congestion and edema, splenic congestion and lymphoid depletion, fibrinoid necrosis of vessels within the spleen, and multifocal pancreatic acinar necrosis. Immunohistochemistry (IHC) was weakly positive for influenza A in the brain; IHC was negative in other tissues tested. The clinical and pathologic characteristics of this case matched previously published material concerning HPAI and add to instances of known or suspected mutation of a low pathogenic virus to a highly pathogenic virus.

Highly Pathogenic Avian Influenza Virus (H5N8) Clade 2.3.4.4 Infection in Migratory Birds, Egypt.

PubMed

Selim, Abdullah A; Erfan, Ahmed M; Hagag, Naglaa; Zanaty, Ali; Samir, Abdel-Hafez; Samy, Mohamed; Abdelhalim, Ahmed; Arafa, Abdel-Satar A; Soliman, Mohamed A; Shaheen, Momtaz; Ibraheem, Essam M; Mahrous, Ibrahim; Hassan, Mohamed K; Naguib, Mahmoud M

2017-06-01

We isolated highly pathogenic avian influenza virus (H5N8) of clade 2.3.4.4 from the common coot (Fulica atra) in Egypt, documenting its introduction into Africa through migratory birds. This virus has a close genetic relationship with subtype H5N8 viruses circulating in Europe. Enhanced surveillance to detect newly emerging viruses is warranted.

Pandemic Threat Posed by Avian Influenza A Viruses

PubMed Central

Horimoto, Taisuke; Kawaoka, Yoshihiro

2001-01-01

Influenza pandemics, defined as global outbreaks of the disease due to viruses with new antigenic subtypes, have exacted high death tolls from human populations. The last two pandemics were caused by hybrid viruses, or reassortants, that harbored a combination of avian and human viral genes. Avian influenza viruses are therefore key contributors to the emergence of human influenza pandemics. In 1997, an H5N1 influenza virus was directly transmitted from birds in live poultry markets in Hong Kong to humans. Eighteen people were infected in this outbreak, six of whom died. This avian virus exhibited high virulence in both avian and mammalian species, causing systemic infection in both chickens and mice. Subsequently, another avian virus with the H9N2 subtype was directly transmitted from birds to humans in Hong Kong. Interestingly, the genes encoding the internal proteins of the H9N2 virus are genetically highly related to those of the H5N1 virus, suggesting a unique property of these gene products. The identification of avian viruses in humans underscores the potential of these and similar strains to produce devastating influenza outbreaks in major population centers. Although highly pathogenic avian influenza viruses had been identified before the 1997 outbreak in Hong Kong, their devastating effects had been confined to poultry. With the Hong Kong outbreak, it became clear that the virulence potential of these viruses extended to humans. PMID:11148006

Characaterization of H5N1 highly pathogenic avian influenza viruses isolated from poultry in Pakistan 2006-2008

USDA-ARS?s Scientific Manuscript database

Nine avian influenza viruses (AIV), H5N1 subtype, were isolated from dead poultry in the Karachi region of Pakistan from 2006-2008. The intravenous pathogenicity indices and HA protein cleavage sites of all nine viruses were consistent with highly pathogenic AIV. Based on phylogenetic analysis of ...

A consensus-hemagglutinin-based vaccine delivered by an attenuated Salmonella mutant protects chickens against heterologous H7N1 influenza virus.

PubMed

Hyoung, Kim Je; Hajam, Irshad Ahmed; Lee, John Hwa

2017-06-13

H7N3 and H7N7 are highly pathogenic avian influenza (HPAI) viruses and have posed a great threat not only for the poultry industry but for the human health as well. H7N9, a low pathogenic avian influenza (LPAI) virus, is also highly pathogenic to humans, and there is a great concern that these H7 subtypes would acquire the ability to spread efficiently between humans, thereby becoming a pandemic threat. A vaccine candidate covering all the three subtypes must, therefore, be an integral part of any pandemic preparedness plan. To address this need, we constructed a consensus hemagglutinin (HA) sequence of H7N3, H7N7, and H7N9 based on the data available in the NCBI in early 2012-2015. This artificial sequence was then optimized for protein expression before being transformed into an attenuated auxotrophic mutant of Salmonella Typhimurium, JOL1863 strain. Immunizing chickens with JOL1863, delivered intramuscularly, nasally or orally, elicited efficient humoral and cell mediated immune responses, independently of the route of vaccination. Our results also showed that JOL1863 deliver efficient maturation signals to chicken monocyte derived dendritic cells (MoDCs) which were characterized by upregulation of costimulatory molecules and higher cytokine induction. Moreover, immunization with JOL1863 in chickens conferred a significant protection against the heterologous LPAI H7N1 virus challenge as indicated by reduced viral sheddings in the cloacal swabs. We conclude that this vaccine, based on a consensus HA, could induce broader spectrum of protection against divergent H7 influenza viruses and thus warrants further study.

Characterization of Avian Influenza and Newcastle Disease Viruses from Poultry in Libya.

PubMed

Kammon, Abdulwahab; Heidari, Alireza; Dayhum, Abdunaser; Eldaghayes, Ibrahim; Sharif, Monier; Monne, Isabela; Cattoli, Giovanni; Asheg, Abdulatif; Farhat, Milad; Kraim, Elforjani

2015-09-01

On March 2013, the Libyan poultry industry faced severe outbreaks due to mixed infections of APMV-1 (Newcastle disease) and low pathogenic avian influenza (AI) of the H9N2 subtype which were causing high mortality and great economic losses. APMV-1 and H9N2 were isolated and characterized. Genetic sequencing of the APMV-1/chicken/Libya/13VIR/ 7225-1/2013 isolate revealed the presence of a velogenic APMV-1 belonging to lineage 5 (GRRRQKR*F Lin.5) or genotype VII in class II, according to the nomenclature in use. Three AI viruses of the H9N2 subtype, namely A/avian/Libya/13VIR7225-2/2013, A/avian/Libya/13VIR7225-3/2013, and A/avian/Libya/13VIR7225-5/2013, were isolated and found to belong to the G1 lineage. Analysis of amino acid sequences showed that the analyzed H9N2 viruses contained the amino acid Leu at position 226 (H3 numbering) at the receptor binding site of the HA, responsible for human virus-like receptor specificity. On March 2014, an outbreak of highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was diagnosed in a backyard poultry farm in an eastern region of Libya. The H5N1 isolate (A/chicken/Libya/14VIR2749-16/2014) was detected by real time RT-PCR (rRT-PCR). Genetic characterization of the HA gene revealed that the identified subtype was highly pathogenic, belonged to the 2.2.1 lineage, and clustered with recent Egyptian viruses. This study revealed the presence of a velogenic APMV-1 genotype and of two influenza subtypes, namely HPAI H5N1 and H9N2, which are of major interest for public and animal health. Considering these findings, more investigations must be undertaken to establish and implement adequate influenza surveillance programs; this would allow better study of the epidemiology of APMV-1 genotype VII in Libya and evaluation of the current vaccination strategies.

Unexpected infection outcomes of China-origin H7N9 low pathogenicity avian influenza virus in turkeys.

PubMed

Slomka, Marek J; Seekings, Amanda H; Mahmood, Sahar; Thomas, Saumya; Puranik, Anita; Watson, Samantha; Byrne, Alexander M P; Hicks, Daniel; Nunez, Alejandro; Brown, Ian H; Brookes, Sharon M

2018-05-09

The China-origin H7N9 low pathogenicity avian influenza virus (LPAIV) emerged as a zoonotic threat in 2013 where it continues to circulate in live poultry markets. Absence of overt clinical signs in poultry is a typical LPAIV infection outcome, and has contributed to its insidious maintenance in China. This study is the first description of H7N9 LPAIV (A/Anhui/1/13) infection in turkeys, with efficient transmission to two additional rounds of introduced contact turkeys which all became infected during cohousing. Surprisingly, mortality was observed in six of eight (75%) second-round contact turkeys which is unusual for LPAIV infection, with unexpected systemic dissemination to many organs beyond the respiratory and enteric tracts, but interestingly no accompanying mutation to highly pathogenic AIV. The intravenous pathogenicity index score for a turkey-derived isolate (0.39) affirmed the LPAIV phenotype. However, the amino acid change L235Q in the haemagglutinin gene occurred in directly-infected turkeys and transmitted to the contacts, including those that died and the two which resolved infection to survive to the end of the study. This polymorphism was indicative of a reversion from mammalian to avian adaptation for the H7N9 virus. This study underlined a new risk to poultry in the event of H7N9 spread beyond China.

Structures of Receptor Complexes of a North American H7N2 Influenza Hemagglutinin with a Loop Deletion in the Receptor Binding Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Hua; Chen, Li-Mei; Carney, Paul J.

2012-02-21

Human infections with subtype H7 avian influenza viruses have been reported as early as 1979. In 1996, a genetically stable 24-nucleotide deletion emerged in North American H7 influenza virus hemagglutinins, resulting in an eight amino acid deletion in the receptor-binding site. The continuous circulation of these viruses in live bird markets, as well as its documented ability to infect humans, raises the question of how these viruses achieve structural stability and functionality. Here we report a detailed molecular analysis of the receptor binding site of the North American lineage subtype H7N2 virus A/New York/107/2003 (NY107), including complexes with an avianmore » receptor analog (3'-sialyl-N-acetyllactosamine, 3'SLN) and two human receptor analogs (6'-sialyl-N-acetyllactosamine, 6'SLN; sialyllacto-N-tetraose b, LSTb). Structural results suggest a novel mechanism by which residues Arg220 and Arg229 (H3 numbering) are used to compensate for the deletion of the 220-loop and form interactions with the receptor analogs. Glycan microarray results reveal that NY107 maintains an avian-type ({alpha}2-3) receptor binding profile, with only moderate binding to human-type ({alpha}2-6) receptor. Thus despite its dramatically altered receptor binding site, this HA maintains functionality and confirms a need for continued influenza virus surveillance of avian and other animal reservoirs to define their zoonotic potential.« less

An epidemiological study of avian influenza A (H5) virus in nomadic ducks and their raising practices in northeastern Bangladesh, 2011-2012.

PubMed

Sarkar, Shamim; Khan, Salah Uddin; Mikolon, Andrea; Rahman, Mohammad Ziaur; Abedin, Jaynal; Zeidner, Nord; Sturm-Ramirez, Katherine; Luby, Stephen P

2017-05-01

In Bangladesh, nomadic duck flocks are groups of domestic ducks reared for egg production that are moved to access feeding sites beyond their owners' village boundaries and are housed overnight in portable enclosures in scavenging areas. The objectives of this study were to measure the prevalence of influenza A virus RNA and H5-specific antibodies in nomadic ducks and to characterize nomadic duck raising practices in northeastern Bangladesh. We tested duck egg yolk specimens by competitive ELISA to detect antibodies against avian influenza A (H5) and environmental fecal samples by real-time reverse-transcription polymerase chain reaction (rRT-PCR) to detect influenza A virus RNA and H5 subtype. The median age of the ducks was 24 months (range: 8-36 months) and the median flock size was 300 ducks (range: 105-1100). Of 1860 egg yolk samples, 556 (30%, 95% confidence interval (CI): 28-32) were positive for antibodies against H5 and 58 flocks (94%) had at least one egg with H5-specific antibodies. Of 496 fecal samples, 121 (24%, 95% CI: 22-29) had detectable influenza A RNA. Thirty-three flocks (53%) had at least one fecal sample positive for influenza A RNA. Nomadic ducks in Bangladesh are commonly infected with avian influenza A (H5) virus and may serve as a bridging host for transmission of avian influenza A (H5) virus or other avian influenza A viruses subtypes between wild waterfowl, backyard poultry, and humans in Bangladesh. © 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.

Antigenic Fingerprinting of Antibody Response in Humans following Exposure to Highly Pathogenic H7N7 Avian Influenza Virus: Evidence for Anti-PA-X Antibodies.

PubMed

Khurana, Surender; Chung, Ka Yan; Coyle, Elizabeth M; Meijer, Adam; Golding, Hana

2016-10-15

Infections with H7 highly pathogenic avian influenza (HPAI) viruses remain a major public health concern. Adaptation of low-pathogenic H7N7 to highly pathogenic H7N7 in Europe in 2015 raised further alarm for a potential pandemic. An in-depth understanding of antibody responses to HPAI H7 virus following infection in humans could provide important insight into virus gene expression as well as define key protective and serodiagnostic targets. Here we used whole-genome gene fragment phage display libraries (GFPDLs) expressing peptides of 15 to 350 amino acids across the complete genome of the HPAI H7N7 A/Netherlands/33/03 virus. The hemagglutinin (HA) antibody epitope repertoires of 15 H7N7-exposed humans identified clear differences between individuals with no hemagglutination inhibition (HI) titers (<1:10) and those with HI titers of >1:40. Several potentially protective H7N7 epitopes close to the HA receptor binding domain (RBD) and neuraminidase (NA) catalytic site were identified. Surface plasmon resonance (SPR) analysis identified a strong correlation between HA1 (but not HA2) binding antibodies and H7N7 HI titers. A proportion of HA1 binding in plasma was contributed by IgA antibodies. Antibodies against the N7 neuraminidase were less frequent but targeted sites close to the sialic acid binding site. Importantly, we identified strong antibody reactivity against PA-X, a putative virulence factor, in most H7N7-exposed individuals, providing the first evidence for in vivo expression of PA-X and its recognition by the immune system during human influenza A virus infection. This knowledge can help inform the development and selection of the most effective countermeasures for prophylactic as well as therapeutic treatments of HPAI H7N7 avian influenza virus. An outbreak of pathogenic H7N7 virus occurred in poultry farms in The Netherlands in 2003. Severe outcome included conjunctivitis, influenza-like illness, and one lethal infection. In this study, we investigated

Protection against avian influenza H9N2 virus challenge by immunization with hemagglutinin- or neuraminidase-expressing DNA in BALB/c mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qiu Meizhen; Fang Fang; Chen Yan

2006-05-19

Avian influenza viruses of H9N2 subtype are widely spread in avian species. The viruses have recently been transmitted to mammalian species, including humans, accelerating the efforts to devise protective strategies against them. In this study, an avian influenza H9N2 virus strain (A/Chicken/Jiangsu/7/2002), isolated in Jiangsu Province, China, was used to infect BALB/c mice for adaptation. After five lung-to-lung passages, the virus was stably proliferated in a large quantity in the murine lung and caused the deaths of mice. In addition, we explored the protection induced by H9N2 virus hemagglutinin (HA)- and neuraminidase (NA)-expressing DNAs in BALB/c mice. Female BALB/c micemore » aged 6-8 weeks were immunized once or twice at a 3-week interval with HA-DNA and NA-DNA by electroporation, respectively, each at a dose of 3, 10 or 30 {mu}g. The mice were challenged with a lethal dose (40x LD{sub 5}) of influenza H9N2 virus four weeks after immunization once or one week after immunization twice. The protections of DNA vaccines were evaluated by the serum antibody titers, residual lung virus titers, and survival rates of the mice. The result showed that immunization once with not less than 10 {mu}g or twice with 3 {mu}g HA-DNA or NA-DNA provided effective protection against homologous avian influenza H9N2 virus.« less