scholarly journals INFLUENZA A AND B VIRUSES CIRCULATING IN THE TERRITORY OF SOUTHERN KAZAKHSTAN DURING 2020-2021 EPIDEMIC PERIOD

2021 ◽  
Author(s):  
С.Б. БАЙСЕЙIТ ◽  
А.М. БАЙМУХАМЕТОВА ◽  
Г.В. ЛУКМАНОВА ◽  
Н.Т. САКТАГАНОВ ◽  
Д.А. ИСМАГУЛОВА ◽  
...  
Keyword(s):  
Influenza A ◽  
Genetic Material ◽  
H3n2 Virus ◽  
Influenza B Virus ◽  
Influenza B ◽  
Inhibition Assay ◽  
Healthcare Facilities ◽  
Virus Rna ◽  
Influenza A H1n1 ◽  
Epidemic Period

В статье показаны результаты мониторинга циркуляции разных серотипов вируса гриппа на территории южного Казахстана в эпидемический период 2020-2021 гг. С этой целью в период с декабря 2020 г. по февраль 2021 г. в лечебных учреждениях различных регионов южного Казахстана от больных людей получено 370 носоглоточных смывов. При скрининге образцов в полимеразной цепной реакции в режиме реального времени обнаружен генетический материал как вируса гриппа А (8,11% случаев), так и вируса гриппа В (5,14%). При субтипировании образцов, положительных на грипп типа А, РНК вируса гриппа A/H1N1/pdm выявлена в 2,97% проб, A/H3N2 – в 3,51%. В результате последовательных пассажей биопроб на куриных эмбрионах выделено три гемагглютинирующих агента, идентифицированных в реакции торможения гемагглютинации и реакции ингибиции нейраминидазной активности как вирусы гриппа А/H1N1pdm, А/H3N2 и типа В. This paper demonstrates the results of monitoring the circulation of different serotypes of influenza virus in the territory of the southern Kazakhstan during the 2020-2021 epidemic period. For this purpose, 370 nasopharyngeal swabs were obtained from patients in healthcare facilities located in various regions of the southern Kazakhstan during the period from December 2020 to February 2021. Screening of samples in real-time polymerase chain reaction has revealed genetic material of both influenza A virus (8.11% of cases) and influenza B virus (5.14%). When subtyping samples positive for influenza type A, the influenza A/H1N1/pdm virus RNA have been detected in 2.97% of samples, while that from the A/H3N2 virus in 3.51%. As a result of successive passages of biosamples in chicken embryos, three hemagglutinating agents have been isolated and identified in the hemagglutination inhibition assay and the neuraminidase inhibition assay as influenza A/H1N1pdm, A/H3N2, and type B viruses.

scholarly journals Transmissibility of influenza during the 21st-century epidemics, Spain, influenza seasons 2001/02 to 2017/18

2020 ◽  
Vol 25 (21) ◽  
Author(s):  
Lidia Redondo-Bravo ◽  
Concepción Delgado-Sanz ◽  
Jesús Oliva ◽  
Tomás Vega ◽  
Jose Lozano ◽  
...  
Keyword(s):  
Influenza A ◽  
Influenza Pandemic ◽  
Age Groups ◽  
H3n2 Virus ◽  
Influenza B Virus ◽  
Influenza B ◽  
Intensity Level ◽  
Influenza A H1n1 ◽  
Epidemic Period ◽  
System Data

Background Understanding influenza seasonality is necessary for determining policies for influenza control. Aim We characterised transmissibility during seasonal influenza epidemics, including one influenza pandemic, in Spain during the 21th century by using the moving epidemic method (MEM) to calculate intensity levels and estimate differences across seasons and age groups. Methods We applied the MEM to Spanish Influenza Sentinel Surveillance System data from influenza seasons 2001/02 to 2017/18. A modified version of Goldstein’s proxy was used as an epidemiological-virological parameter. We calculated the average starting week and peak, the length of the epidemic period and the length from the starting week to the peak of the epidemic, by age group and according to seasonal virus circulation. Results Individuals under 15 years of age presented higher transmissibility, especially in the 2009 influenza A(H1N1) pandemic. Seasons with dominance/co-dominance of influenza A(H3N2) virus presented high intensities in older adults. The 2004/05 influenza season showed the highest influenza-intensity level for all age groups. In 12 seasons, the epidemic started between week 50 and week 3. Epidemics started earlier in individuals under 15 years of age (−1.8 weeks; 95% confidence interval (CI):−2.8 to −0.7) than in those over 64 years when influenza B virus circulated as dominant/co-dominant. The average time from start to peak was 4.3 weeks (95% CI: 3.6–5.0) and the average epidemic length was 8.7 weeks (95% CI: 7.9–9.6). Conclusions These findings provide evidence for intensity differences across seasons and age groups, and can be used guide public health actions to diminish influenza-related morbidity and mortality.

Population immunity for influenza in population of Sverdlovsk Region in epidemic season of 2018–2019

2020 ◽  
pp. 26-28
Author(s):  
I. A. Malchikov ◽  
A. V. Slobodenyuk ◽  
I. V. Vyalykh ◽  
A. Yu. Markaran ◽  
Yu. V. Grigorieva ◽  
...  
Keyword(s):  
Influenza A ◽  
Adult Population ◽  
Laboratory Data ◽  
Influenza Viruses ◽  
H3n2 Virus ◽  
Influenza B Virus ◽  
Influenza B ◽  
Epidemic Season ◽  
Influenza A H1n1 ◽  
Epidemic Period

Donor blood serum was tested to detect antibodies against circulating influenza viruses. The titer of specific antibodies was determined in the hemagglutination inhibition test (RTGA) against influenza viruses A/California/07/09(H1N1) pdm09, A/HongKong/4801/14(H3N2) and B/Brisben/46/15. In the pre-epidemic period 2018–2019, the immune layer of people with conditionally protective titers of antiviral antibodies was detected in terms of the lowest to A(H3N2) virus (50.0 %), the highest to influenza B (85.4 %). In the post-epidemic season of 2018–2019, the immune layer to influenza A(H1N1) pdm09 virus did not change significantly, which could indicate the preservation of the activity of this virus in the adult population; an increase in the immune layer of individuals with protective titers of antibodies to influenza A(H3N2) – 67.4 % and a decrease in influenza B virus – 49.2 %. A comparison of the results of laboratory data carried out in the pre- and post-epidemic seasons revealed significant differences in the number of people with average antibody titers against influenza A(H3N2) and B viruses (p < 0.05).

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.

Influenza A(H1N1)pdm 2009 and influenza B virus co-infection in hospitalized and non-hospitalized patients during the 2015–2016 epidemic season in Israel

2017 ◽  
Vol 88 ◽  
pp. 12-16 ◽  
Author(s):  
Rakefet Pando ◽  
Yaron Drori ◽  
Nehemya Friedman ◽  
Aharona Glatman-Freedman ◽  
Hanna Sefty ◽  
...  
Keyword(s):  
Influenza A ◽  
Hospitalized Patients ◽  
Influenza B Virus ◽  
Influenza B ◽  
Epidemic Season ◽  
Influenza A H1n1 ◽  
B Virus

scholarly journals DRIFT OF INFLUENA A(H3N2) VIRUS: BIOLOGICAL, ANTIGENIC AND GENETIC PROPERTIES IN EPIDEMIC SEASON 2016-2017 IN RUSSIA AND COUNTRIES OF THE NOTHERN HEMYSPHERE

2018 ◽  
Vol 63 (2) ◽  
pp. 61-68 ◽  
Author(s):  
D. K. Lvov ◽  
E. I. Burtseva ◽  
E. S. Kirillova ◽  
L. V. Kolobukhina ◽  
E. A. Mukasheva ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Northern Hemisphere ◽  
Influenza A ◽  
H3n2 Virus ◽  
Research Centre ◽  
Federal State ◽  
Influenza B Virus ◽  
Influenza B ◽  
Epidemic Season ◽  
B Virus

The article presents the features of the influenza virus circulation for the period from October 2016 to May 2017 in some territories of Russia collaborating with the D.I. Ivanovsky Institute of Virology, Federal State Budgetary Institution “N.F. Gamaleya Federal Research Centre for Epidemiology and Microbiology”, Ministry of Health of the Russian Federation. One of the 2016-2017 season’s peculiarities in Russia and countries of the Northern hemisphere was the earlier start of an increase in ARD morbidity with peak indexes reached towards the end of December 2016 - January 2017. First, influenza A(H3N2) virus was predominant; then, it was followed by influenza B virus activity observed until the end of the season. The indexes of morbidity were higher than in the previous season, while the rates of hospitalization and mortality were lower, lethal cases being detected in persons 65 years old and older. Epidemic strains of influenza A(H3N2) virus belonged to 3c.2a genetic group, reference strain A/Hong Hong/4408/2014, and its subgroup 3c.2a1, reference A/Bolzano/7/2016, that are antigenically similar. Strains of influenza B virus were antigenically similar to the B/Brisbane/60/2008 vaccine virus. Strains were sensitive to oseltamivir and zanamivir. The share participation of non-influenza ARI viruses was similar to preliminary epidemic seasons. WHO has issued recommendations for influenza virus vaccines composition for 2017-2018 for the Northern hemisphere.

scholarly journals Influenza A(H1N1)pdm09 But Not A(H3N2) Virus Infection Induces Durable Seroprotection: Results From the Ha Nam Cohort

2020 ◽  
Author(s):  
Le Nguyen Minh Hoa ◽  
Sheena G Sullivan ◽  
Le Quynh Mai ◽  
Arseniy Khvorov ◽  
Hoang Vu Mai Phuong ◽  
...  
Keyword(s):  
Influenza A ◽  
Virus Transmission ◽  
H3n2 Virus ◽  
Inhibition Assay ◽  
Hemagglutination Inhibition Assay ◽  
Younger Age ◽  
Influenza A H1n1 ◽  
Antibody Titers ◽  
Waning Immunity ◽  
Prior Infection

Abstract Background The extent to which influenza recurrence depends upon waning immunity from prior infection is undefined. We used antibody titers of Ha-Nam cohort participants to estimate protection curves and decay trajectories. Methods Households (270) participated in influenza-like–illness (ILI) surveillance and provided blood at intervals spanning laboratory–confirmed virus transmission. Sera were tested in hemagglutination inhibition assay. Infection was defined as influenza virus-positive ILI and/or seroconversion. Median protective titers were estimated using scaled-logistic regression to model pretransmission titer against infection status in that season, limiting analysis to households with infection(s). Titers were modelled against month since infection using mixed-effects linear regression to estimate decay and when titers fell below protection thresholds. Results From December 2008–2012, 295 and 314 participants were infected with H1N1pdm09-like and A/Perth/16/09-like (H3N2Pe09) viruses, respectively. The proportion protected rose more steeply with titer for H1N1pdm09 than for H3N2Pe09, and estimated 50% protection titers were 19.6 and 37.3, respectively. Postinfection titers started higher against H3N2Pe09 but decayed more steeply than against H1N1pdm09. Seroprotection was estimated to be sustained against H1N1pdm09 but to wane by 8-months for H3N2Pe09. Conclusions Estimates indicate that infection induces durable seroprotection against H1N1pdm09 but not H3N2Pe09, which could in part account for the younger age of A(H1N1) versus A(H3N2) cases.

scholarly journals In Vitro Characterization of the Carbohydrate-Binding Agents HHA, GNA and UDA as Inhibitors of Influenza a and B Virus Replication

2020 ◽  
Author(s):  
Evelien Vanderlinden ◽  
Nathalie Van Winkel ◽  
Lieve Naesens ◽  
Els J. M. Van Damme ◽  
Leentje Persoons ◽  
...  
Keyword(s):  
Influenza A ◽  
Inhibitory Effect ◽  
H3n2 Virus ◽  
Influenza B ◽  
Carbohydrate Binding ◽  
Membrane Glycoproteins ◽  
Influenza A H1n1 ◽  
Binding Agents ◽  
Continuous Presence

Here, we report on the anti-influenza virus activity of the mannose-binding agents, Hippeastrum hybrid agglutinin (HHA) and Galanthus nivalis agglutinin (GNA), and the (N-acetylglucosamine)n-specific Urtica dioica agglutinin (UDA). These carbohydrate-binding agents (CBA) strongly inhibited various influenza A(H1N1), A(H3N2) and B viruses in vitro, with EC50 values ranging from 0.016 to 83 nM, generating selectivity indexes up to 125,000. Somewhat less activity was observed against the A/PR/8/34 and an A(H1N1)pdm09 strain. In time-of-addition experiments, these CBA lost their inhibitory activity when added 30 min p.i. Interference with virus entry processes was also evident from strong inhibition of virus-induced hemolysis at low pH. However, a direct effect on acid-induced refolding of the viral hemagglutinin (HA) was excluded by the tryptic digestion assay. Instead, HHA treatment of HA-expressing cells led to a significant reduction of plasma membrane mobility. Crosslinking of membrane glycoproteins, through interaction with HA, could also explain the inhibitory effect on the release of newly formed virions when HHA was added at 6 h p.i. These CBA presumably interact with one or more N-glycans on the globular head of HA, since their absence led to reduced activity against mutant influenza B viruses and HHA-resistant A(H1N1) viruses. The latter condition only emerged after 33 cell culture passages in the continuous presence of HHA, and the A(H3N2) virus even retained full sensitivity after 50 passages. Thus, these CBA qualify as potent inhibitors of influenza A and B viruses in vitro with a pleiotropic mechanism of action and a high barrier for viral resistance.

scholarly journals Serological studies of influenza viruses in pigs in Great Britain 1991–2

1995 ◽  
Vol 114 (3) ◽  
pp. 511-520 ◽  
Author(s):  
I. H. Brown ◽  
P. A. Harris ◽  
D. J. Alexander
Keyword(s):  
Great Britain ◽  
Influenza A ◽  
H1n1 Virus ◽  
Haemagglutination Inhibition ◽  
Influenza Viruses ◽  
Antigenic Drift ◽  
H3n2 Virus ◽  
Influenza B Virus ◽  
Influenza B ◽  
Influenza A Viruses

SUMMARYSamples from a sow serum bank representative of the pig population of Great Britain collected during 1991–2, were examined for antibodies to influenza A, B and C viruses, using viruses which had been isolated from a variety of hosts. For influenza A viruses there was evidence of the continued circulation of ‘classical swine’ H1N1 virus (26%) seroprevalence), and human H3N2 viruses (39%) which are antigenically most closely-related to A/Port Chalmers/1/73 virus. In addition antibodies were detected to A/swine/England/201635/92 (8%), a strain of H3N2 virus which appears to have arisen by antigenic drift from conventional H3N2 swine strains. Specific antibodies (2%) were detected to an H1N1 virus (A/swine/England/195852/92) related most closely to avian H1N1 strains. In tests with human H1N1 and H3N2 viruses, excluding isolates from pigs, the highest seroprevalence was detected to the prevailing strains from the human population. Serological tests with avian H4 and H10, human H2, equine 1 and 2 influenza A viruses were all negative. Seven pigs seropositive by haemagglutination-inhibition, virus neutralization and immunoblotting assays for antibody to influenza B virus, were randomly distributed geographically suggesting that influenza B viruses may be transmitted to pigs but fail to spread. The seroprevalence to influenza C viruses was 9·9% indicating that these viruses are widespread in pigs. These results provide further evidence that the pig can be infected by a number of influenza viruses, some of which may have significance in the epidemiology of human influenza.

scholarly journals Enhancement of the Influenza Surveillance System in the Russian Federation: the Main Results of the Sentinel Surveillance for Influenza and other Acute Respiratory Viral Infections

2017 ◽  
Vol 16 (1) ◽  
pp. 7-15 ◽  
Author(s):  
A. A. Sominina ◽  
E. A. Smorodintseva ◽  
K. A. Stolyarov ◽  
A. A. Mel'nikova
Keyword(s):  
Respiratory Infection ◽  
Surveillance System ◽  
Acute Respiratory Infection ◽  
Influenza A ◽  
Hospitalized Patients ◽  
Sentinel Surveillance ◽  
Influenza Surveillance ◽  
Influenza B Virus ◽  
Influenza B ◽  
Influenza A H1n1

Existing influenza surveillance system is constantly improved to obtain comprehensive information for understanding of continuously changing situation with the influenza, which is a consequence of the highest variability of the pathogen, its ability to reassortment and the imminence of emergence a new shift-variants of the virus that could cause the next pandemic events. For this purpose, since the 2010 - 2011 epidemic season, in addition to the traditional surveillance system (TS) a new well standardized sentinel surveillance system (SS) for rapid clinical and epidemiological data obtaining was introduced in Russia. A total 7812 hospitalized patients with severe acute respiratory infection (SARI) and 9854 outpatients with influenza-like illness and acute respiratory infection (ILI/ARI) were investigated during the 6-year period in SS. Percent of SARI among all hospitalized patients ranged from 1.7 to 3.1%; about 5.3 - 7.5% SARI patients were placed in the Intensive Care Unit. Etiological monitoring using PCR showed influenza spread trends in SS similar to those registered in the TS: a clear predominance of influenza A (H1N1) pdm09 among SARI and ILI/ARI in 2010 - 2011 and 2015 - 2016 epidemic seasons, influenza A (H3N2) in the epidemic seasons 2011 - 2012 and 2014 - 2015, the co-circulation of these pathogens in 2012 - 2013, 2013 - 2014 seasons in Russia. SARI caused by influenza B virus were detected less frequently than influenza A but increased influenza B activity was registered in the epidemic of 2014 -2015, when Yamagata lineage changed suddenly for the Victorian one. The average frequency of influenza diagnosis among SARI between the seasons varied in the range 12.5 - 27.1%, at the peak of the epidemic it reached 44.8 - 73.5% and was the highest during the season with active circulation of influenza A (H1N1) pdm09 virus. The rate of influenza diagnosis among ILI/ARI has always been lower than that among SARI. Studies have also shown the importance of rhinovirus, RS-virus and parainfluenza infections in SARI development. The frequency of registration of coronaviruses, metapneumovirus and bocavirus infection was very low in SARI and ILI/ARI. It was found that in all studied seasons most of SARI patients with influenza have not been vaccinated. Among ILI/ARI outpatients with influenza, the frequency of vaccinated individuals for the entire period of the study was estimated as 10.1%, which was 4.2 times higher than that in SARI, where only 2.4% of patients were vaccinated. In addition, it was found that for all six seasons the SARI patients with influenza were treated with antivirals drugs 2 times less often compared to outpatients. Analysis of data on concomitant diseases and conditions in SARI patients with influenza confirmed the leading role of pregnancy as a risk factor for hospitalization in all influenza epidemics, irrespective of their etiology. In addition, diabetes and cardiovascular disease were recognized as risk factors for influenza associated SARI development.

scholarly journals Prevalence of Influenza Virus Type and Subtype at Siriraj Hospital, Bangkok, Thailand During 2013 - 2017

2020 ◽  
Vol 43 (3) ◽  
pp. 1-7
Author(s):  
Nattapol Narong ◽  
Siriwat Manajit ◽  
Sirikarn Athipanyasil ◽  
Niracha Athipanyasilp ◽  
Ruengpung Sutthent ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Respiratory Illness ◽  
Influenza B Virus ◽  
Influenza B ◽  
Influenza A H1n1 ◽  
B Virus ◽  
Siriraj Hospital

Background: Influenza A (pandemic and seasonal H1/H3) and influenza B viruses were the predominant circulating seasonal influenza strains. Following its massive outbreak in 2009 globally, including Thailand, influenza A (H1N1) pdm09 viruses have replaced the previous seasonal H1 strain and become one of the circulating strains ever since. Both influenza A and B viruses are highly contagious and potentially cause respiratory illness ranging from mild to severe. Objective: To determine the prevalence of types and subtypes of circulating influenza virus strains in Bangkok, Thailand during 2013 - 2017. Methods: The 4385 nasopharyngeal wash specimens were collected from patients presented with influenza-like illness from January 2013 to December 2017 at Siriraj Hospital, Bangkok, Thailand. Influenza virus types and subtypes were determined using real-time RT-PCR technique. Clinical characteristics of patients infected with influenza A viruses and influenza B virus were compared and analyzed. Results: Of 4385 nasopharyngeal wash specimens, the prevalence of influenza virus infection during 2013 - 2017 was 18.22% (n = 799). Of 799 influenza-positive samples, 608 (76.09%) and 191 (23.90%) samples were positive for influenza A and influenza B viruses, respectively. Most patients were presented with fever, cough, and runny nose; however, patients infected with influenza A virus generally had higher severity than those with influenza B virus infection (P < .05). Conclusions: The findings provided the characteristics of influenza virus types and subtypes at Siriraj Hospital, Bangkok, Thailand during 2013 - 2017. Sporadic cases of influenza occurred all year round, but the incidence peaked in March 2014 and August 2017. The outcomes of this study are potentially useful for prevention, treatment, and disease monitoring.  

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