scholarly journals Distribution of influenza viruses in Northern Greece during 1972–1983

1984 ◽  
Vol 93 (2) ◽  
pp. 263-267 ◽  
Author(s):  
V. Kyriazopoulou-Dalaina
Keyword(s):  
Time Scale ◽  
Influenza A ◽  
World Wide ◽  
Type A ◽  
Influenza Viruses ◽  
Influenza B ◽  
Type B ◽  
Influenza A Viruses ◽  
Northern Greece

SummaryObservations on the circulation of influenza viruses in Northern Greece during the winters of 1972/3 to 1982/3 are presented.Influenza A viruses were detected every winter with the exception of those of 1973/4 and 1981/2, when neither type A nor type B was isolated. The strains of type A isolated during the study period were similar to those circulating world-wide over the same time scale.Influenza B viruses were isolated only during the winters of 1972/3 and 1979/80; influenza A viruses were also circulating in the community at those times. The B strains detected were similar to those recorded world-wide during the period of study.

scholarly journals Biophysical and immunological studies on the differential effect of guanidine hydrochloride on type A and type B influenza viruses

1974 ◽  
Vol 72 (1) ◽  
pp. 31-39
Author(s):  
Tam. S. David-West
Keyword(s):  
Biological Activity ◽  
Differential Effect ◽  
Influenza A ◽  
Guanidine Hydrochloride ◽  
Type A ◽  
Influenza Viruses ◽  
Influenza B ◽  
Type B

SUMMARYGuanidine hydrochloride selectively inactivated both the biological activity and the immunogenicity of the haemagglutinin of influenza A/X-7 (H0N2). The residual neuraminidase was fully active biologically and immunologically. The reverse was observed with influenza B/ROB; with this virus the haemagglutinin was resistant, and was immunogenic; while the neuraminidase was selectively inactivated, and was not immunogenic.

scholarly journals Generation of Influenza A Viruses with Chimeric (Type A/B) Hemagglutinins

2003 ◽  
Vol 77 (14) ◽  
pp. 8031-8038 ◽  
Author(s):  
Taisuke Horimoto ◽  
Ayato Takada ◽  
Kiyoko Iwatsuki-Horimoto ◽  
Masato Hatta ◽  
Hideo Goto ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Influenza A ◽  
Reverse Genetics ◽  
Lethal Dose ◽  
Type A ◽  
Influenza Viruses ◽  
Type B ◽  
Wild Type ◽  
Influenza A Viruses ◽  
Contributing Factors

ABSTRACT To gain insight into the intertypic incompatibility between type A and B influenza viruses, we focused on the hemagglutinin (HA) gene, systematically studying the compatibility of chimeric (type A/B) HAs with a type A genetic background. An attempt to generate a reassortant containing an intact type B HA segment in a type A virus background by reverse genetics was unsuccessful despite transcription of the type B HA segment by the type A polymerase complex. Although a type A virus with a chimeric HA segment comprising the entire coding sequence of the type B HA flanked by the noncoding sequence of the type A HA was viable, it replicated only marginally. Other chimeric viruses contained type A/B HAs possessing the type A noncoding region together with either the signal peptide or transmembrane/cytoplasmic region of type A virus or both, with the remaining regions derived from the type B HA. Each of these viruses grew to median tissue culture infectious doses of more than 105 per ml, but those with more type A HA regions replicated better, suggesting protein-protein interactions or increased HA segment incorporation into virions as contributing factors in the efficient growth of this series of viruses. All of these chimeric (A/B) HA viruses were attenuated in mice compared with wild-type A or B viruses. All animals intranasally immunized with a chimeric virus survived upon challenge with a lethal dose of wild-type type B virus. These results suggest a framework for the design of a novel live vaccine virus.

scholarly journals IDENTIFICATION OF INFLUENZA VIRUSES IN HUMAN AND POULTRY IN THE AREA OF LARANGAN WET MARKET SIDOARJO-EAST JAVA, INDONESIA

2013 ◽  
Vol 4 (4) ◽  
pp. 30
Author(s):  
Edith Frederika ◽  
Aldise Mareta ◽  
Djoko Poetranto ◽  
Laksmi Wulandari ◽  
Retno Asih Setyoningrum ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Type ◽  
Influenza A ◽  
Type A ◽  
Influenza Viruses ◽  
Nasopharyngeal Swab ◽  
Type B ◽  
Influenza A Viruses ◽  
Type C ◽  
Wet Market

Background: Influenza is a viral infection that attacks the respiratory system (nose, throat, and lungs) that commonly known as “flu”. There are 3 types of influenza viruses, such as type A, type B, and type C. Influenza virus type A is the type of virus that can infect both human and animals, virus type B are normally found only in human, and Influenza virus type C can cause mild illness in human and not causing any epidemics or pandemics. Among these 3 types of influenza viruses, only influenza A viruses infect birds, particularly wild bird that are the natural host for all subtypes of influenza A virus. Generally, those wild birds do not get sick when they are infected with influenza virus, unlike chickens or ducks which may die from avian influenza. Aim: In this study, we are identifying the influenza viruses among poultry in Larangan wet market. Method: Around 500 kinds of poultry were examined from cloacal swab. Result: Those samples were restrained with symptoms of suspected H5. The people who worked as the poultry-traders intact with the animal everyday were also examined, by taking nasopharyngeal swab and blood serum. Conclusion: Identification of influenza viruses was obtained to define the type and subtype of influenza virus by PCR.

scholarly journals An evaluation of the InDevR FluChip-8G insight microarray assay in characterizing influenza a viruses

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Emily S. Bailey ◽  
Xinye Wang ◽  
Mai-juan Ma ◽  
Guo-lin Wang ◽  
Gregory C. Gray
Keyword(s):  
Influenza A ◽  
Influenza Viruses ◽  
Time Range ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Laboratory Methods ◽  
Duke University ◽  
Multiple Viral Strains ◽  
Rapid Characterization

AbstractInfluenza viruses are an important cause of disease in both humans and animals, and their detection and characterization can take weeks. In this study, we sought to compare classical virology techniques with a new rapid microarray method for the detection and characterization of a very diverse, panel of animal, environmental, and human clinical or field specimens that were molecularly positive for influenza A alone (n = 111), influenza B alone (n = 3), both viruses (n = 13), or influenza negative (n = 2) viruses. All influenza virus positive samples in this study were first subtyped by traditional laboratory methods, and later evaluated using the FluChip-8G Insight Assay (InDevR Inc. Boulder, CO) in laboratories at Duke University (USA) or at Duke Kunshan University (China). The FluChip-8G Insight multiplexed assay agreed with classical virologic techniques 59 (54.1%) of 109 influenza A-positive, 3 (100%) of the 3 influenza B-positive, 0 (0%) of 10 both influenza A- and B-positive samples, 75% of 24 environmental samples including those positive for H1, H3, H7, H9, N1, and N9 strains, and 80% of 22 avian influenza samples. It had difficulty with avian N6 types and swine H3 and N2 influenza specimens. The FluChip-8G Insight assay performed well with most human, environmental, and animal samples, but had some difficulty with samples containing multiple viral strains and with specific animal influenza strains. As classical virology methods are often iterative and can take weeks, the FluChip-8G Insight Assay rapid results (time range 8 to 12 h) offers considerable time savings. As the FluChip-8G analysis algorithm is expected to improve over time with addition of new subtypes and sample matrices, the FluChip-8G Insight Assay has considerable promise for rapid characterization of novel influenza viruses affecting humans or animals.

scholarly journals Influenza: An Emerging and Re-emerging Public Health Threat in Nepal

2018 ◽  
Vol 3 (2) ◽  
pp. 1-2
Author(s):  
Bishnu Prasad Upadhyay
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Winter Season ◽  
Emerging Infectious Diseases ◽  
Influenza Viruses ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Influenza A H1n1 ◽  
New Variant ◽  
Seasonal Epidemics

Influenza virus type A and B are responsible for seasonal epidemics as well as pandemics in human. Influenza A viruses are further divided into two major groups namely, low pathogenic seasonal influenza (A/H1N1, A/H1N1 pdm09, A/H3N2) and highly pathogenic influenza virus (H5N1, H5N6, H7N9) on the basis of two surface antigens: hemagglutinin (HA) and neuraminidase (NA). Mutations, including substitutions, deletions, and insertions, are one of the most important mechanisms for producing new variant of influenza viruses. During the last 30 years; more than 50 viral threat has been evolved in South-East Asian countriesof them influenza is one of the major emerging and re-emerging infectious diseases of global concern. Similar to tropical and sub-tropical countries of Southeast Asia; circulation of A/H1N1 pdm09, A/H3N2 and influenza B has been circulating throughout the year with the peak during July-November in Nepal. However; the rate of infection transmission reach peak during the post-rain and winter season of Nepal.

scholarly journals Influenza A and B viruses in the population of Vojvodina, Serbia

2014 ◽  
Vol 66 (1) ◽  
pp. 43-50 ◽  
Author(s):  
J. Radovanov ◽  
V. Milosevic ◽  
I. Hrnjakovic ◽  
V. Petrovic ◽  
M. Ristic ◽  
...  
Keyword(s):  
Influenza A ◽  
Respiratory Infections ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Nasopharyngeal Swab ◽  
Influenza B ◽  
Influenza A Viruses ◽  
B Virus ◽  
Life Threatening ◽  
Seasonal Epidemic

At present, two influenza A viruses, H1N1pdm09 and H3N2, along with influenza B virus co-circulate in the human population, causing endemic and seasonal epidemic acute febrile respiratory infections, sometimes with life-threatening complications. Detection of influenza viruses in nasopharyngeal swab samples was done by real-time RT-PCR. There were 60.2% (53/88) positive samples in 2010/11, 63.4% (52/82) in 2011/12, and 49.9% (184/369) in 2012/13. Among the positive patients, influenza A viruses were predominant during the first two seasons, while influenza B type was more active during 2012/13. Subtyping of influenza A positive samples revealed the presence of A (H1N1)pdm09 in 2010/11, A (H3N2) in 2011/12, while in 2012/13, both subtypes were detected. The highest seroprevalence against influenza A was in the age-group 30-64, and against influenza B in adults aged 30-64 and >65.

scholarly journals Non-Uniform and Non-Random Binding of Nucleoprotein to Influenza A and B Viral RNA

Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 522 ◽  
Author(s):  
Valerie Le Sage ◽  
Adalena Nanni ◽  
Amar Bhagwat ◽  
Dan Snyder ◽  
Vaughn Cooper ◽  
...  
Keyword(s):  
Influenza A ◽  
Gene Segment ◽  
Influenza Viruses ◽  
Viral Rna ◽  
Influenza B Virus ◽  
Viral Gene ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Binding Profile ◽  
Random Manner

The genomes of influenza A and B viruses have eight, single-stranded RNA segments that exist in the form of a viral ribonucleoprotein complex in association with nucleoprotein (NP) and an RNA-dependent RNA polymerase complex. We previously used high-throughput RNA sequencing coupled with crosslinking immunoprecipitation (HITS-CLIP) to examine where NP binds to the viral RNA (vRNA) and demonstrated for two H1N1 strains that NP binds vRNA in a non-uniform, non-random manner. In this study, we expand on those initial observations and describe the NP-vRNA binding profile for a seasonal H3N2 and influenza B virus. We show that, similar to H1N1 strains, NP binds vRNA in a non-uniform and non-random manner. Each viral gene segment has a unique NP binding profile with areas that are enriched for NP association as well as free of NP-binding. Interestingly, NP-vRNA binding profiles have some conservation between influenza A viruses, H1N1 and H3N2, but no correlation was observed between influenza A and B viruses. Our study demonstrates the conserved nature of non-uniform NP binding within influenza viruses. Mapping of the NP-bound vRNA segments provides information on the flexible NP regions that may be involved in facilitating assembly.

scholarly journals The evolution of human influenza viruses

2001 ◽  
Vol 356 (1416) ◽  
pp. 1861-1870 ◽  
Author(s):  
Alan J. Hay ◽  
Victoria Gregory ◽  
Alan R. Douglas ◽  
Yi Pu Lin
Keyword(s):  
Influenza A ◽  
Influenza Viruses ◽  
Antigenic Drift ◽  
Influenza B ◽  
Mixed Infections ◽  
Human Influenza ◽  
Influenza A Viruses ◽  
Genetic Reassortment ◽  
Influenza Ah1n1 ◽  
Novel Influenza A

The evolution of influenza viruses results in (i) recurrent annual epidemics of disease that are caused by progressive antigenic drift of influenza A and B viruses due to the mutability of the RNA genome and (ii) infrequent but severe pandemics caused by the emergence of novel influenza A subtypes to which the population has little immunity. The latter characteristic is a consequence of the wide antigenic diversity and peculiar host range of influenza A viruses and the ability of their segmented RNA genomes to undergo frequent genetic reassortment (recombination) during mixed infections. Contrasting features of the evolution of recently circulating influenza AH1N1, AH3N2 and B viruses include the rapid drift of AH3N2 viruses as a single lineage, the slow replacement of successive antigenic variants of AH1N1 viruses and the co–circulation over some 25 years of antigenically and genetically distinct lineages of influenza B viruses. Constant monitoring of changes in the circulating viruses is important for maintaining the efficacy of influenza vaccines in combating disease.

scholarly journals Antiviral drug resistance in seasonal and pandemic influenza

2011 ◽  
Vol 32 (1) ◽  
pp. 26
Author(s):  
Aeron C Hurt
Keyword(s):  
Drug Resistance ◽  
Human Population ◽  
Influenza A ◽  
Antiviral Drug ◽  
Influenza Viruses ◽  
Antiviral Resistance ◽  
Influenza B ◽  
Neuraminidase Inhibitors ◽  
Influenza A Viruses ◽  
Antiviral Drug Resistance

Two classes of anti-influenza drugs are currently available for the treatment or prophylaxis of influenza. These are the adamantanes (amantadine and rimantadine), which block the activity of the M2 ion channel of influenza A viruses (but not influenza B viruses), and the neuraminidase inhibitors (NAIs), which act by binding to the enzymatic site of the influenza neuraminidase (NA) thereby preventing progeny virions from being released from the host cell during viral replication. Antiviral resistance can occur in influenza viruses and render the drug ineffective for the treatment of patients. Virtually all influenza A viruses currently circulating in the human population are resistant to the adamantanes, while in comparison these viruses remain susceptible to the NAIs. In particular, very low NAI resistance has been observed in pandemic A(H1N1) 2009 viruses, even though unprecedented amounts of these drugs were used.

scholarly journals Influenza B viruses exhibit lower within-host diversity than influenza A viruses in human hosts

2019 ◽  
Author(s):  
Andrew L. Valesano ◽  
William J. Fitzsimmons ◽  
John T. McCrone ◽  
Joshua G. Petrie ◽  
Arnold S. Monto ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Influenza A Virus ◽  
Influenza A ◽  
Evolutionary Dynamics ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Community Based ◽  
B Virus

AbstractInfluenza B virus undergoes seasonal antigenic drift more slowly than influenza A, but the reasons for this difference are unclear. While the evolutionary dynamics of influenza viruses play out globally, they are fundamentally driven by mutation, reassortment, drift, and selection within individual hosts. These processes have recently been described for influenza A virus, but little is known about the evolutionary dynamics of influenza B virus (IBV) at the level of individual infections and transmission events. Here we define the within-host evolutionary dynamics of influenza B virus by sequencing virus populations from naturally-infected individuals enrolled in a prospective, community-based cohort over 8176 person-seasons of observation. Through analysis of high depth-of-coverage sequencing data from samples from 91 individuals with influenza B, we find that influenza B virus accumulates lower genetic diversity than previously observed for influenza A virus during acute infections. Consistent with studies of influenza A viruses, the within-host evolution of influenza B viruses is characterized by purifying selection and the general absence of widespread positive selection of within-host variants. Analysis of shared genetic diversity across 15 sequence-validated transmission pairs suggests that IBV experiences a tight transmission bottleneck similar to that of influenza A virus. These patterns of local-scale evolution are consistent with influenza B virus’ slower global evolutionary rate.ImportanceThe evolution of influenza virus is a significant public health problem and necessitates the annual evaluation of influenza vaccine formulation to keep pace with viral escape from herd immunity. Influenza B virus is a serious health concern for children, in particular, yet remains understudied compared to influenza A virus. Influenza B virus evolves more slowly than influenza A, but the factors underlying this are not completely understood. We studied how the within-host diversity of influenza B virus relates to its global evolution by sequencing viruses from a community-based cohort. We found that influenza B virus populations have lower within-host genetic diversity than influenza A virus and experience a tight genetic bottleneck during transmission. Our work provides insights into the varying dynamics of influenza viruses in human infection.

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