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 Molecular Epidemiology and Antigenic Characterization of Seasonal Influenza Viruses Circulating in Nepal

2017 ◽  
Vol 15 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Bishu Prasad Upadhyay ◽  
Prakash Ghimire ◽  
Masato Tashiro ◽  
Mogha Raj Banjara
Keyword(s):  
New York ◽  
Influenza Virus ◽  
Molecular Epidemiology ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza B ◽  
Antigenic Characterization ◽  
Geographical Regions ◽  
Influenza A H1n1 ◽  
Health Burdens

Background: Influenza is one of the public health burdens in Nepal and its epidemiology is not clearly understood. The objective of this study was to explore the molecular epidemiology and the antigenic characteristics of the circulating influenza viruses in Nepal.Methods: A total of 1495 throat swab specimens were collected from January to December, 2014. Real time PCR assay was used for identification of influenza virus types and subtypes. Ten percent of the positive specimens were randomly selected and inoculated onto Madin-Darby Canine Kidney Epithelial cells (MDCK) for influenza virus isolation. All viruses were characterized by the hemagglutination inhibition (HI) assay.Results: Influenza viruses were detected in 421/1495 (28.2%) specimens. Among positive cases, influenza A virus was detected in 301/421 (71.5%); of which 120 (39.9%) were influenza A/H1N1 pdm09 and 181 (60.1%) were influenza A/H3 subtype. Influenza B viruses were detected in 119/421 (28.3%) specimens. Influenza A/H1N1 pdm09, A/H3 and B viruses isolated in Nepal were antigenically similar to the vaccine strain influenza A/California/07/2009(H1N1pdm09), A/Texas/50/2012(H3N2), A/New York/39/2012(H3N2) and B/Massachusetts/2/2012, respectively.Conclusions: Influenza viruses were reported year-round in different geographical regions of Nepal which was similar to other tropical countries. The circulating influenza virus type and subtypes of Nepal were similar to vaccine candidate virus which could be prevented by currently used influenza vaccine.

scholarly journals Mapping inhibitory sites on the RNA polymerase of the 1918 pandemic influenza virus using nanobodies

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Jeremy R. Keown ◽  
Zihan Zhu ◽  
Loïc Carrique ◽  
Haitian Fan ◽  
Alexander P. Walker ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Rna Polymerase ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Structural Data ◽  
Influenza Viruses ◽  
Viral Rna ◽  
Influenza A Viruses ◽  
Seasonal Epidemics ◽  
1918 Influenza

AbstractInfluenza A viruses cause seasonal epidemics and global pandemics, representing a considerable burden to healthcare systems. Central to the replication cycle of influenza viruses is the viral RNA-dependent RNA polymerase which transcribes and replicates the viral RNA genome. The polymerase undergoes conformational rearrangements and interacts with viral and host proteins to perform these functions. Here we determine the structure of the 1918 influenza virus polymerase in transcriptase and replicase conformations using cryo-electron microscopy (cryo-EM). We then structurally and functionally characterise the binding of single-domain nanobodies to the polymerase of the 1918 pandemic influenza virus. Combining these functional and structural data we identify five sites on the polymerase which are sensitive to inhibition by nanobodies. We propose that the binding of nanobodies at these sites either prevents the polymerase from assuming particular functional conformations or interactions with viral or host factors. The polymerase is highly conserved across the influenza A subtypes, suggesting these sites as effective targets for potential influenza antiviral development.

scholarly journals Tropism of SARS-CoV-2, SARS-CoV and influenza virus in canine tissue explants

2021 ◽  
Author(s):  
Christine H T Bui ◽  
H W Yeung ◽  
John C W Ho ◽  
Connie Y H Leung ◽  
Kenrie P Y Hui ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Influenza A ◽  
Ex Vivo ◽  
Influenza Viruses ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Avian Influenza Viruses ◽  
Canine Influenza Virus ◽  
Wide Range

Abstract Background Human spillovers of SARS-CoV-2 to dogs and the emergence of a highly contagious avian-origin H3N2 canine influenza virus have raised concerns towards the role of dogs in the spread of SARS-CoV-2 and their susceptibility to existing human and avian influenza viruses which might result in further reassortment. Methods We systematically studied the replication kinetics of SARS-CoV-2, SARS-CoV, influenza A viruses of H1, H3, H5, H7 and H9 subtypes and influenza B viruses of Yamagata-like and Victoria-like lineages in ex-vivo canine nasal cavity (NC), soft palate (SP), trachea (T) and lung (L) tissue explant cultures and examined ACE2 and sialic acid (SA) receptor distribution in these tissues. Results There was limited productive replication of SARS-CoV-2 in canine NC and SARS-CoV in canine NC, SP and L with unexpectedly high ACE2 levels in canine NC and SP. Meanwhile, the canine tissues were susceptible to a wide range of human and avian influenza viruses, which matched with the abundance of both human and avian SA receptors. Conclusions Existence of suitable receptors and tropism for the same tissue foster virus adaptation and reassortment. Continuous surveillance in dog populations should be conducted given the plenty of chances for spillover during outbreaks.

scholarly journals Interaction Among Influenza Viruses A/H1N1, A/H3N2, and B in Japan

2019 ◽  
Vol 16 (21) ◽  
pp. 4179 ◽  
Author(s):  
Ayako Suzuki ◽  
Kenji Mizumoto ◽  
Andrei R. Akhmetzhanov ◽  
Hiroshi Nishiura
Keyword(s):  
Influenza Virus ◽  
Virus Type ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Winter Season ◽  
The United States ◽  
Influenza Viruses ◽  
Statistical Correlations ◽  
Epidemic Size ◽  
Influenza A H1n1

Seasonal influenza epidemics occur each winter season in temperate zones, involving up to 650,000 deaths each year globally. A published study demonstrated that the circulation of one influenza virus type during early influenza season in the United States interferes with the activity of other influenza virus types. However, this finding has yet to be validated in other settings. In the present work, we investigated the interaction among seasonal influenza viruses (A/H1N1, A/H3N2 and B) in Japan. Sentinel and virus surveillance data were used to estimate the type-specific incidence from 2010 to 2019, and statistical correlations among the type-specific incidence were investigated. We identified significant negative correlations between incidence of the dominant virus and the complementary incidence. When correlation was identified during the course of an epidemic, a linear regression model accurately predicted the epidemic size of a particular virus type before the epidemic peak. The peak of influenza type B took place later in the season than that of influenza A, although the epidemic peaks of influenza A/H1N1 and A/H3N2 nearly coincided. Given the interaction among different influenza viruses, underlying mechanisms including age and spatial dependence should be explored in future.

scholarly journals Morbidity patterns associated with seasonal influenza A/H1N1in Swaziland

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Vusie Lokotfwako ◽  
Nhlanhla Nhlabatsi ◽  
Phinda Khumalo ◽  
Siphiwe Shongwe ◽  
Bongani Tsabedze ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Influenza A ◽  
Seasonal Influenza ◽  
Index Case ◽  
Influenza Viruses ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Epidemic Disease ◽  
Influenza A H1n1 ◽  
Private Laboratory

ObjectiveTo establish morbidity patterns of influenza A/H1N1 in Swaziland from 10th July to 15th August 2017.IntroductionInfluenza infection is caused by the influenza virus, a single-stranded RNA virus belonging to the Orthomyxoviridae family. Influenza viruses are classified as types A, B and C. Influenza A and B viruses can cause epidemic disease in humans and type C viruses usually cause a mild, cold-like illness. The influenza virus spreads rapidly around the world in seasonal epidemics, resulting in significant morbidity and mortality. On the 10th of July 2017, a case of confirmed Influenza A/H1N1 was reported through the immediate disease notification system from a private hospital in the Hhohho region. A 49 year old female was diagnosed of Influenza A/H1N1 after presenting with flu-like symptoms. Contacts of the index case were followed and further positive cases were identified.MethodsUpon identification of the index case, the rapid response teams conducted further investigations. Two nasal swaps from each sample were taken and sent to a private laboratory in South Africa for the detection of the virus RNA using RT-PCR to assess for the presence Influenza A, B and Influenza A/H1N1. Further laboratory results were sourced from a private laboratory to monitor trends of influenza. Data was captured and analyzed in STATA version 12 from STATA cooperation. Descriptive statistics were carried out using means and standard deviations. The Pearson Chi square test and student t test were used to test for any possible association between influenza A/H1N1 and the explanatory variables (age and sex).ResultsSurveillance data captured between 10th July 2017 and 15th August 2017 indicated that a total of 87 patients had their samples taken for laboratory confirmation. There were 45 females and 42 males and the mean age was 27 years (SD= 17). At least 25 of the 87 patients tested positive for influenza A while only 1 tested positive for influenza B. The prevalence of influenza A/H1N1 was 16%. The prevalence of influenza A/H1N1 among males was 19% compared to 13% in females; however the difference was not statistically significant (p=0.469). There was no association noted between age and influenza A/H1N1 (p=427). Upon further sub-typing results indicated that the circulating strain was influenza A/H1N1 pdm 09 strain which is a seasonal influenza. The epidemic task forces held weekly and ad-hoc meetings to provide feedback to principals and health messaging to the general population to allay anxiety.ConclusionsThough WHO has classified the influenza A/H1N1 strain pdm 0029 as a seasonal influenza, surveillance remains important for early detection and management. There is therefore an urgent need to set up sentinel sites to monitor and understand the circulating influenza strains. Health promotion remains crucial to dispel anxiety as the general public still link any influenza to the 2009 pandemic influenza. Finally the Ministry of Health should consider introducing influenza vaccines into the routine immunization schedule especially for children.References1. Global Epidemiological Surveillance Standards for Influenza. 2014 [cited 2015 15 April]; Available from: http://www.who.int/influenza/resources/documents/influenza_surveillance_manual/en/.2. Human cases of influenza at the human-animal interface, 2013. Wkly Epidemiol Rec, 2014.89(28): p. 309-20.3. WHO Global Influenza Surveillance Network. Manual for the laboratory diagnosis and virological surveillance of influenza. 2011 [cited 2015 April27]; Available from: http://www.who.int/influenza/gisrs_laboratory/manual_diagnosis_surveillance_influenza/en/.

scholarly journals A species-specific signature residue in the PB2 subunit of the bat influenza virus polymerase restricts viral RNA synthesis.

2021 ◽  
Author(s):  
Saptarshi Banerjee ◽  
Aratrika De ◽  
Nandita Kedia ◽  
Lin-Fa Wang ◽  
Arindam Mondal
Keyword(s):  
Influenza Virus ◽  
Cell Lines ◽  
Influenza A ◽  
Polymerase Activity ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
Bat Virus ◽  
Influenza A H1n1 ◽  
Chimeric Rna ◽  
Species Specific

Bat influenza A viruses (H17N10 and H18N11) are genetically distant from conventional influenza A viruses and replicates poorly in non-bat hosts species. However, the reason behind the lower replication fitness of these viruses are yet to be elucidated. In this work, we have identified species-specific signature residues, present in viral PB2 protein, which is a major determinant of polymerase fitness in human, avian and bat cell lines. Through extensive sequence and structural comparison between the bat and non-bat influenza virus RNA polymerases, we have identified a previously uncharacterized PB2-282 residue, which is serine in bat virus PB2 protein but harbours highly conserved glutamic acid in conventional influenza A viruses. Introduction of these bat specific signatures in the polymerase of a human adapted strain of influenza A/H1N1 virus drastically reduces its polymerase activity and replication efficiency in cell lines of human, bat and canine origin. In contrast, introduction of the human-specific signatures in bat virus PB2 (H17N10), significantly enhances its function in the context of a chimeric RNA polymerase. Interestingly, the PB2-282 resides within an evolutionary conserved 'S-E-S' motif present across different genera of influenza viruses but is replaced with a 'S-S-T' motif in bat influenza viruses, indicating that this E to S transition may serve as a species-specific adaptation signature that modulates the activity of bat virus polymerase in other host species.

scholarly journals Etiology of influenza-like illnesses in the population of Novosibirsk city in the 2018–2019 epidemic season

2021 ◽  
Vol 11 (4) ◽  
pp. 723-736
Author(s):  
O. G. Kurskaya ◽  
A. V. Anoshina ◽  
N. V. Leonova ◽  
O. A. Simkina ◽  
T. V. Komissarova ◽  
...  
Keyword(s):  
Influenza A ◽  
Detection Rate ◽  
Respiratory Viruses ◽  
Influenza Viruses ◽  
Influenza B Virus ◽  
Influenza B ◽  
Monitoring And Control ◽  
Influenza A Viruses ◽  
Surveillance Network ◽  
Influenza A H1n1

Influenza and other acute respiratory viral infections lead to a substantial incidence of severe cases and hospitalizations and so remain a global health problem. Within the frame of the Global Influenza Hospital Surveillance Network (GIHSN), we assessed the contribution of influenza and other respiratory viruses to severe cases of influenzalike diseases in patients hospitalized to the Novosibirsk infectious hospitals in the years 2018–2019. We analyzed 484 nasopharyngeal swabs collected from patients admitted to the hospitals with acute respiratory infections (ARI) using real-time polymerase chain reaction commercial kits. We confirmed viral etiology of ARI in 69.8% cases. Influenza viruses were detected in 47.1% cases, wherein concomitant circulation of influenza A(H1N1)pdm09 and A(H3N2) viruses was observed in 20.7% and 26% of patients, respectively, whereas influenza B virus was detected only in one sample. All analyzed influenza A viruses were antigenically similar to vaccine strains. Genetically, the Novosibirsk strains were closely related to influenza A viruses distributed in Russia and worldwide. Influenza A(H1N1)pdm09 virus was detected in all patients aged 0 to 14 years and required intensive care. Other respiratory viruses were detected in 36.4% of children and 5.8% of adults, and 8.3% of children had viral coinfection, whereas no cases of coinfection were detected in adults. The most common viruses in children were metapneumovirus — 12.8%, rhinovirus — 9.3% and respiratory syncytial virus — 8.0%. In adults, metapneumovirus, adenovirus, parainfluenza virus and rhinovirus were detected with a detection rate no exceeding 2%. In this study, we found no differences in the detection rate of the influenza virus due to concomitant chronic diseases, pregnancy, or smoking habits. At the same time, the detection rate of other respiratory viruses in non-smokers vs. smokers was significantly lower than in smokers and former smokers (26.15%, 66.67% and 62.50%, respectively). In addition, the level of detection of respiratory viruses in children with vs. without chronic pathology was significantly higher (55.3% and 38.7%, respectively). Thus, our and similar studies are important for monitoring and control of the infection.

scholarly journals Evaluation of four real-time PCR assays for detection of influenza A(H1N1)v viruses

2009 ◽  
Vol 14 (22) ◽  
Author(s):  
J Ellis ◽  
M Iturriza ◽  
R Allan ◽  
A Bermingham ◽  
K Brown ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Influenza A ◽  
Influenza Viruses ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Concurrent Use ◽  
Influenza A H1n1 ◽  
Similar Range ◽  
Pcr Assays

The sensitivity and specificity of four real-time PCR assays (HPA A(H1)v, CDC A (H1)v, HPA A(N1)v and NVRL S-OIV assays) was evaluated for detection of influenza A(H1N1)v viruses. Nose and throat swab samples containing influenza A(H1N1)v viruses, seasonal influenza AH3N2, AH1N1, influenza B viruses, or negative for influenza viruses were tested by the four assays. Specificity was also analysed using influenza A viruses of different subtypes and non-related respiratory viruses. The sensitivities and specificities of the four assays were in a similar range and suitable for diagnostic use. The HPA (H1)v and the S-OIV assays were the most sensitive assays for use as a first line test, but the S-OIV assay was less specific, detecting all avian subtypes of influenza A viruses tested. The results of this study demonstrate that the concurrent use of primary diagnostic and confirmatory assays provides rapid and accurate assessment of confirmed cases, and allows appropriate management of patients.

scholarly journals Effectiveness of influenza vaccine in preventing medically-attended influenza virus infection in primary care, Israel, influenza seasons 2014/15 and 2015/16

2018 ◽  
Vol 23 (7) ◽  
Author(s):  
Hamutal Yaron-Yakoby ◽  
Hanna Sefty ◽  
Rakefet Pando ◽  
Rita Dichtiar ◽  
Mark A Katz ◽  
...  
Keyword(s):  
Primary Care ◽  
Influenza Virus ◽  
Influenza Vaccine ◽  
Influenza A ◽  
Influenza Season ◽  
Influenza Virus Infection ◽  
Influenza Viruses ◽  
Influenza B ◽  
Negative Case ◽  
Influenza A H1n1

Introduction Influenza vaccine is recommended for the entire population in Israel. We assessed influenza vaccine effectiveness (VE) for the 2014/15 and 2015/16 seasons in Israel, for the first time. Methods: Combined nose and throat swab specimens were collected from patients with influenza-like illness (ILI) presenting to sentinel primary care clinics and tested for influenza virus by RT-PCR. VE of the trivalent inactivated vaccine (TIV) was assessed using test-negative case–control design. Results: During the 2014/15 season 1,142 samples were collected; 327 (28.6%) were positive for influenza, 83.8% A(H3N2), 5.8% A(H1N1)pdm09, 9.2% B and 1.2% A un-subtyped. Adjusted VE against all influenza viruses for this influenza season was −4.8% (95% confidence interval (CI): −54.8 to 29.0) and against influenza A(H3N2), it was −15.8% (95% CI: −72.8 to 22.4). For the 2015/16 season, 1,919 samples were collected; 853 (44.4%) were positive for influenza, 43.5% A(H1N1)pdm09, 57% B, 0.7% A(H3N2) and 11 samples positive for both A(H1N1)pdm09 and B. Adjusted VE against all influenza viruses for this influenza season was 8.8% (95% CI: −25.1 to 33.5), against influenza A(H1N1)pdm09, it was 32.3% (95% CI: (−4.3 to 56.1) and against influenza B, it was −2.2% (95% CI: (−47.0 to 29.0). Conclusions: Using samples from patients with ILI visiting sentinel clinics in Israel, we demonstrated the feasibility of influenza VE estimation in Israel.

scholarly journals MONOCLONAL ANTIBODIES TO HEMAGGLUTININ OF INFLUENZA B VIRUSES VICTORIA EVOLUTIONARY LINEAGE

2018 ◽  
Vol 63 (6) ◽  
pp. 275-280
Author(s):  
E. V. Sorokin ◽  
T. R. Tsareva ◽  
A. I. Zheltukhina
Keyword(s):  
Influenza Virus ◽  
Hemagglutination Inhibition ◽  
Influenza A ◽  
Rapid Identification ◽  
Influenza Viruses ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Antigenic Analysis ◽  
Epidemic Season ◽  
Evolutionary Lineage

Co-circulation of two evolutionary distinct lineages of influenza virus in one epidemic season has led to development specific reagents for rapid identification and typing of new isolates. Panel of MAbs to hemagglutinin of influenza virus B/Brisbane/46/15 belonging to Victoria evolutionary lineage was developed. All MAbs reacted in ELISA with B/Victoria-like strains only. There were no interactions with heterologous influenza viruses of B/Yamagata lineage, seasonal and potentially pandemic influenza A viruses. All MAbs reacted in hemagglutination inhibition and virus neutralization. MAbs interacted in hemagglutination inhibition only with B/Victoria-like viruses, but did not interacted B/Yamagata-like strains. Neutralization and hemagglutination inhibition studies of viruses isolated before 1983 with MAbs revealed that MAbs 6E11, 9G5, 9B5 and 6A4 had the ability to interact with the virus B/ Russia/69 which may evidence that B strains of early isolation period (before lineage separation) have common epitope with recent Victoria lineage viruses. MAbs 7C8, 7G9, 7H8 and 8D11 were directed to a conserved epitope (or epitopes) specific for influenza hemagglutinin viruses of B/Victoria group. The presence of differences in the effectiveness of the interaction of MAbs 6A9, 7G9 and 8A8 in hemagglutination inhibition test allows the identification and differentiation of strains isolated in chicken embryos and MDCK cell culture. Thus, the developed MAbs can be successfully used for identification and antigenic analysis of B/Victoria-like strains.

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