Local Spread of Influenza A (H1N1) Viruses Without A Mutation For The Maximum Duration of An Epidemic Season In Japan

2021 ◽  
Author(s):  
Seiji Kageyama ◽  
Akeno Tsuneki-Tokunaga ◽  
Kyosuke Kanai
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Epidemic Season ◽  
Local Spread ◽  
Maximum Duration ◽  
Influenza A H1n1 ◽  
Close Observation ◽  
Transmission Period ◽  
Local Transmission

Abstract Close observation of the local transmission of influenza A(H1N1) viruses enabled an estimation of the transmission period of the virus without a mutation. Of 4,448 isolates from 11 consecutive years, 237 isolates could be categorized into 57 strain groups with identical hemagglutinin genes. Transmission of these 57 strains was chased for the maximum duration of an epidemic season. In addition, 35 identical strains were recognized at the study site and other countries within 147 days. Consequently, it can be postulated that once an influenza virus enters a temperate country, the strain rarely mutates until the end of the season.

scholarly journals Local spread of influenza A (H1N1) viruses without a mutation for the maximum duration of an epidemic season in Japan

2021 ◽  
Author(s):  
Akeno Tsuneki-Tokunaga ◽  
Takanori Kondo ◽  
Kyosuke Kanai ◽  
Asao Itagaki ◽  
Hideaki Tsuchie ◽  
...  
Keyword(s):  
Influenza A ◽  
Epidemic Season ◽  
Local Spread ◽  
Maximum Duration ◽  
Influenza A H1n1

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 Complete Genome Sequences of Influenza A/H1N1 Strains Isolated from Patients during the 2013-2014 Epidemic Season in Finland

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Petri Jalovaara ◽  
Polina Mishel ◽  
Hannimari Kallio-Kokko ◽  
Miia Valkonen ◽  
Anu Kantele ◽  
...  
Keyword(s):  
Complete Genome ◽  
Influenza A ◽  
Genome Sequences ◽  
Epidemic Season ◽  
Influenza A H1n1

scholarly journals Entry screening to delay local transmission of 2009 pandemic influenza A (H1N1)

2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Benjamin J Cowling ◽  
Lincoln LH Lau ◽  
Peng Wu ◽  
Helen WC Wong ◽  
Vicky J Fang ◽  
...  
Keyword(s):  
Pandemic Influenza ◽  
Influenza A ◽  
Influenza A H1n1 ◽  
Local Transmission

scholarly journals MOLECULAR AND GENETIC CHARACTERISTICS OF SURFACE AND NONSTRUCTURE PROTEINS OF PANDEMIC INFLUENZA VIRUSES A(H1N1)PDM09 IN 2015-2016 EPIDEMIC SEASON

2016 ◽  
Vol 72 (2) ◽  
pp. 44-48
Author(s):  
O. Smutko ◽  
L. Radchenko ◽  
A. Mironenko
Keyword(s):  
Amino Acid ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Phylogenetic Trees ◽  
Influenza Viruses ◽  
Amino Acid Substitutions ◽  
Ns1 Protein ◽  
Genetic Characteristics ◽  
Epidemic Season ◽  
Influenza A H1n1

The aim of the present study was identifying of molecular and genetic changes in hemaglutinin (HA), neuraminidase (NA) and non-structure protein (NS1) genes of pandemic influenza A(H1N1)pdm09 strains, that circulated in Ukraine during 2015-2016 epidemic season. Samples (nasopharyngeal swabs from patients) were analyzed using real-time polymerase chain reaction (RTPCR). Phylogenetic trees were constructed using MEGA 7 software. 3D structures were constructed in Chimera 1.11.2rc software. Viruses were collected in 2015-2016 season fell into genetic group 6B and in two emerging subgroups, 6B.1 and 6B.2 by gene of HA and NA. Subgroups 6B.1 and 6B.2 are defined by the following amino acid substitutions. In the NS1 protein were identified new amino acid substitutions D2E, N48S, and E125D in 2015-2016 epidemic season. Specific changes were observed in HA protein antigenic sites, but viruses saved similarity to vaccine strain. NS1 protein acquired substitution associated with increased virulence of the influenza virus.

scholarly journals Detailed Molecular Interactions of Favipiravir with SARS-CoV-2, SARS-CoV, MERS-CoV, and Influenza Virus Polymerases In Silico

2020 ◽  
Vol 8 (10) ◽  
pp. 1610 ◽  
Author(s):  
Mitsuru Sada ◽  
Takeshi Saraya ◽  
Haruyuki Ishii ◽  
Kaori Okayama ◽  
Yuriko Hayashi ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Molecular Interactions ◽  
In Silico ◽  
Influenza A ◽  
Active Sites ◽  
Active Form ◽  
Antiviral Drug ◽  
Virus Rna ◽  
Influenza A H1n1 ◽  
In Silico Studies

Favipiravir was initially developed as an antiviral drug against influenza and is currently used in clinical trials against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection (COVID-19). This agent is presumably involved in RNA chain termination during influenza virus replication, although the molecular interactions underlying its potential impact on the coronaviruses including SARS-CoV-2, SARS-CoV, and Middle East respiratory syndrome coronavirus (MERS-CoV) remain unclear. We performed in silico studies to elucidate detailed molecular interactions between favipiravir and the SARS-CoV-2, SARS-CoV, MERS-CoV, and influenza virus RNA-dependent RNA polymerases (RdRp). As a result, no interactions between favipiravir ribofuranosyl-5′-triphosphate (F-RTP), the active form of favipiravir, and the active sites of RdRps (PB1 proteins) from influenza A (H1N1)pdm09 virus were found, yet the agent bound to the tunnel of the replication genome of PB1 protein leading to the inhibition of replicated RNA passage. In contrast, F-RTP bound to the active sites of coronavirus RdRp in the presence of the agent and RdRp. Further, the agent bound to the replicated RNA terminus in the presence of agent, magnesium ions, nucleotide triphosphate, and RdRp proteins. These results suggest that favipiravir exhibits distinct mechanisms of action against influenza virus and various coronaviruses.

HA1-2-fljB Vaccine Induces Immune Responses against Pandemic Swine-Origin H1N1 Influenza Virus in Mice

2016 ◽  
Vol 26 (6) ◽  
pp. 422-432 ◽  
Author(s):  
Xilong Kang ◽  
Yun Yang ◽  
Yang Jiao ◽  
Hongqin Song ◽  
Li Song ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
H1n1 Virus ◽  
Influenza Virus Infection ◽  
Candidate Vaccine ◽  
Major Barrier ◽  
Excellent Starting Point ◽  
Starting Point ◽  
Influenza A H1n1 ◽  
N Terminus

In 2009, a novel pandemic swine-origin influenza A (H1N1) virus caused a public emergency of international concern. Vaccination is the primary strategy for the control of influenza epidemics. However, the poor immunopotency of many vaccine antigens is a major barrier to the development of effective vaccines against influenza. Flagellin, a Toll-like receptor 5 (TLR5) ligand, has been used as an adjuvant to enhance the immunopotency of vaccines in preclinical studies. Here, we developed a recombinant candidate vaccine, HA1-2-fljB, in which the globular head of the hemagglutinin (HA) antigen (residues 62-284) from H1N1 virus was fused genetically to the N-terminus of <i>Salmonella typhimurium</i> &#xFB02;jB. The recombinant HA1-2-fljB protein was expressed efficiently in<i> Escherichia coli</i>, and the immunogenicity and protective efficacy of recombinant HA1-2-fljB were evaluated in a mouse model. Immunization with HA1-2-fljB elicited robust IgG antibodies and neutralizing antibodies and completely protected the mice against infection by swine-origin influenza A/swine/Jangsu/38/2010 (H1N1). These results suggest that HA antigen placed at the N-terminus of flagellin is also an excellent starting point for creating a fusion HA1-2-fljB protein as a candidate vaccine, and the recombinant HA1-2-fljB protein will contribute to the development of a more effective vaccine against swine-origin influenza virus infection.

Dual and Triple Infections With Influenza A and B Viruses: A Case-Control Study in Southern Brazil

2019 ◽  
Vol 220 (6) ◽  
pp. 961-968 ◽  
Author(s):  
Tatiana Schäffer Gregianini ◽  
Ivana R Santos Varella ◽  
Patricia Fisch ◽  
Letícia Garay Martins ◽  
Ana B G Veiga
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Clinical Symptoms ◽  
Antiviral Treatment ◽  
Influenza Virus Infection ◽  
H3n2 Virus ◽  
Influenza Surveillance ◽  
Influenza B Virus ◽  
Influenza B ◽  
Influenza A H1n1

Abstract Influenza surveillance is important for disease control and should consider possible coinfection with different viruses, which can be associated with disease severity. This study analyzed 34 459 patients with respiratory infection from 2009 to 2018, of whom 8011 were positive for influenza A virus (IAV) or influenza B virus (IBV). We found 18 cases of dual influenza virus infection, including coinfection with 2009 pandemic influenza A(H1N1) virus (A[H1N1]pdm09) and influenza A(H3N2) virus (1 case), A(H1N1)pdm09 and IBV (6 cases), A(H3N2) and IBV (8 cases), and nonsubtyped IAV and IBV (3 cases); and 1 case of triple infection with A(H3N2), A(H1N1)pdm09, and IBV. Compared with 76 monoinfected patients, coinfection was significantly associated with cardiopathy and death. Besides demographic characteristics and clinical symptoms, we assessed vaccination status, antiviral treatment, timeliness of antiviral use, hospitalization, and intensive care unit admission, but no significant differences were found between coinfected and monoinfected cases. Our findings indicate that influenza virus coinfection occurs more often than previously reported and that it can lead to a worse disease outcome.

scholarly journals The PA Subunit of the Influenza Virus Polymerase Complex Affects Replication and Airborne Transmission of the H9N2 Subtype Avian Influenza Virus

Viruses ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 40 ◽  
Author(s):  
Mengchan Hao ◽  
Shaojie Han ◽  
Dan Meng ◽  
Rong Li ◽  
Jing Lin ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Guinea Pigs ◽  
Influenza A ◽  
Reverse Genetics ◽  
Species Barrier ◽  
Airborne Transmission ◽  
H9n2 Subtype ◽  
Influenza A H1n1

The polymerase acidic (PA) protein is the third subunit of the influenza A virus polymerase. In recent years, studies have shown that PA plays an important role in overcoming the host species barrier and host adaptation of the avian influenza virus (AIV). The objective of this study was to elucidate the role of the PA subunit on the replication and airborne transmission of the H9N2 subtype AIV. By reverse genetics, a reassortant rSD01-PA was derived from the H9N2 subtype AIV A/Chicken/Shandong/01/2008 (SD01) by introducing the PA gene from the pandemic influenza A H1N1 virus A/swine/Shandong/07/2011 (SD07). Specific pathogen-free (SPF) chickens and guinea pigs were selected as the animal models for replication and aerosol transmission studies. Results show that rSD01-PA lost the ability of airborne transmission among SPF chickens because of the single substitution of the PA gene. However, rSD01-PA could infect guinea pigs through direct contact, while the parental strain SD01 could not, even though the infection of rSD01-PA could not be achieved through aerosol. In summary, our results indicate that the protein encoded by the PA gene plays a key role in replication and airborne transmission of the H9N2 subtype AIV.

scholarly journals Occurrence of influenza B/Hong Kong-Like strains in Brazil, during 2002

2003 ◽  
Vol 45 (1) ◽  
pp. 51-52 ◽  
Author(s):  
Terezinha Maria de Paiva ◽  
Maria Akiko Ishida ◽  
Maria Gisele Gonçalves ◽  
Margareth Aparecida Benega ◽  
Maria Candida Oliveira de Souza ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Hong Kong ◽  
Influenza A ◽  
Vaccination Campaign ◽  
Age Groups ◽  
Respiratory Illness ◽  
The Elderly ◽  
Influenza B ◽  
Surveillance Period ◽  
Influenza A H1n1

Through the influenza virus surveillance from January to October 2002, influenza B/Hong Kong-like strains circulating in the Southeast and Centre East regions of Brazil have been demonstrated. This strain is a variant from B/Victoria/02/88 whose since 1991 and until recently have been isolated relatively infrequently and have been limited to South-Eastern Asia. A total of 510 respiratory secretions were collected from patients 0 to 60 years of age, with acute respiratory illness, living in the Southeast and Centre East regions of Brazil, of which 86 (17.13%) were positive for influenza virus. Among them 12 (13.95%) were characterized as B/Hong Kong/330/2001; 3 (3.49%) as B/Hong Kong/1351/2002 a variant from B/Hong Kong/330/2001; 1 (1.16%) as B/Sichuan/379/99; 1 (1.16%) as B/Shizuoka/5/2001, until now. The percentages of cases notified during the surveillance period were 34.88%, 15.12%, 15.12%, 4.65%, 15.12%, 13.95%, in the age groups of 0-4, 5-10, 11-15, 16-20, 21-30, 31-50, respectively. The highest proportion of isolates was observed among children younger than 4 years but serious morbidity and mortality has not been observed among people older than 65 years, although B influenza virus component for vaccination campaign 2002 was B/Sichuan/379/99 strain. This was probably due to the elderly protection acquired against B/Victoria/02/88. In addition, in influenza A/Panama/2007/99-like (H3N2) strains 22 (25.58%) were also detected, but influenza A(H1N1) has not been detected yet.

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