scholarly journals Epidemiological and evolutionary dynamics of influenza B virus in coastal Kenya as revealed by genomic analysis of strains sampled over a single season

2020 ◽  
Vol 6 (2) ◽  
Author(s):  
Festus M Nyasimi ◽  
David Collins Owuor ◽  
Joyce M Ngoi ◽  
Alexander G Mwihuri ◽  
Grieven P Otieno ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Control Strategies ◽  
Genomic Analysis ◽  
Respiratory Illness ◽  
Influenza B Virus ◽  
Influenza B ◽  
Genomic Epidemiology ◽  
Coastal Kenya ◽  
B Virus ◽  
N 93

Abstract The genomic epidemiology of influenza B virus (IBV) remains understudied in Africa despite significance to design of effective local and global control strategies. We undertook surveillance throughout 2016 in coastal Kenya, recruiting individuals presenting with acute respiratory illness at nine outpatient health facilities (any age) or admitted to the Kilifi County Hospital (<5 years old). Whole genomes were sequenced for a selected 111 positives; 94 (84.7%) of B/Victoria lineage and 17 (15.3%) of B/Yamagata lineage. Inter-lineage reassortment was detected in ten viruses; nine with B/Yamagata backbone but B/Victoria NA and NP segments and one with a B/Victoria backbone but B/Yamagata PB2, PB1, PA, and MP segments. Five phylogenomic clusters were identified among the sequenced viruses; (i), pure B/Victoria clade 1A (n = 93, 83.8%), (ii), reassortant B/Victoria clade 1A (n = 1, 0.9%), (iii), pure B/Yamagata clade 2 (n = 2, 1.8%), (iv), pure B/Yamagata clade 3 (n = 6, 5.4%), and (v), reassortant B/Yamagata clade 3 (n = 9, 8.1%). Using divergence dates and clustering patterns in the presence of global background sequences, we counted up to twenty-nine independent IBV strain introductions into the study area (∼900 km2) in 2016. Local viruses, including the reassortant B/Yamagata strains, clustered closely with viruses from neighbouring Tanzania and Uganda. Our study demonstrated that genomic analysis provides a clearer picture of locally circulating IBV diversity. The high number of IBV introductions highlights the challenge in controlling local influenza epidemics by targeted approaches, for example, sub-population vaccination or patient quarantine. The finding of divergent IBV strains co-circulating within a single season emphasises why broad immunity vaccines are the most ideal for influenza control in Kenya.

scholarly journals Transmission and evolutionary dynamics of human coronavirus OC43 strains in coastal Kenya investigated by partial spike sequence analysis, 2015–16

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Carol A Abidha ◽  
Joyce Nyiro ◽  
Everlyn Kamau ◽  
Osman Abdullahi ◽  
David James Nokes ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Evolutionary Dynamics ◽  
Control Strategies ◽  
Respiratory Illness ◽  
Respiratory Pathogen ◽  
Human Coronavirus ◽  
Spike Gene ◽  
Low Genetic Diversity ◽  
Coastal Kenya ◽  
Close Phylogenetic Relationship

Abstract Human coronavirus OC43 (HCoV-OC43) is a major contributor to seasonal outbreaks of acute respiratory illness (ARI). The origins of locally circulating HCoV-OC43 strains and characteristics of their genetic diversity are unknown for most settings despite significance to effective HCoV control strategies. Between December 2015 and June 2016, we undertook ARI surveillance in coastal Kenya in nine outpatients and one inpatient health facility (HF). Ninety-two patient samples tested HCoV-OC43 positive and forty (43.5%) were successfully sequenced in spike (S) gene region (2,864 long, ∼70%). Phylogenetic analysis confirmed co-circulation of two distinct HCoV-OC43 clades that closely clustered with genotype G (n = 34, 85%) and genotype H (n = 6, 15%) reference strains. Local viruses within the same clade displayed low genetic diversity yielding identical sequences in multiple HF. Furthermore, the newly sequenced Kenyan viruses showed close phylogenetic relationship to other contemporaneous sampled strains (2015–16) including those originating from distant places (e.g. USA and China). Using a genetic similarity threshold of 99.1 per cent at nucleotide level, the HCoV-OC43 strains sampled globally between 1967 and 2019 fell into nine sequence clusters. Notably, some of these clusters appeared to have become extinct, or occurred only sporadically in a few geographical areas while others persisted globally for multiple years. In conclusion, we found that HCoV-OC43 strains spread rapidly both locally and across the globe with limited genetic evolution in the spike gene. Full-genome sequences that are spatio-temporally representative are required to advance understanding of the transmission pathways of this important human respiratory pathogen.

scholarly journals Co-circulation of the two influenza B lineages during 13 consecutive influenza surveillance seasons in Italy, 2004–2017

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Simona Puzelli ◽  
◽  
Angela Di Martino ◽  
Marzia Facchini ◽  
Concetta Fabiani ◽  
...  
Keyword(s):  
Influenza A ◽  
Respiratory Illness ◽  
Influenza Surveillance ◽  
Influenza B Virus ◽  
Influenza B ◽  
Virus Infections ◽  
Ha Gene ◽  
B Virus ◽  
B Lineage ◽  
Trivalent Vaccine

Abstract Background Since 1985, two antigenically distinct lineages of influenza B viruses (Victoria-like and Yamagata-like) have circulated globally. Trivalent seasonal influenza vaccines contain two circulating influenza A strains but a single B strain and thus provide limited immunity against circulating B strains of the lineage not included in the vaccine. In this study, we describe the characteristics of influenza B viruses that caused respiratory illness in the population in Italy over 13 consecutive seasons of virological surveillance, and the match between the predominant influenza B lineage and the vaccine B lineage, in each season. Methods From 2004 to 2017, 26,886 laboratory-confirmed influenza cases were registered in Italy, of which 18.7% were type B. Among them, the lineage of 2465 strains (49%) was retrieved or characterized in this study by a real-time RT-PCR assay and/or sequencing of the hemagglutinin (HA) gene. Results Co-circulation of both B lineages was observed each season, although in different proportions every year. Overall, viruses of B/Victoria and B/Yamagata lineages caused 53.3 and 46.7% of influenza B infections, respectively. A higher proportion of infections with both lineages was detected in children, and there was a declining frequency of B/Victoria detections with age. A mismatch between the vaccine and the predominant influenza B lineage occurred in eight out of thirteen influenza seasons under study. Considering the seasons when B accounted for > 20% of all laboratory-confirmed influenza cases, a mismatch was observed in four out of six seasons. Phylogenetic analysis of the HA1 domain confirmed the co-circulation of both lineages and revealed a mixed circulation of distinct evolutionary viral variants, with different levels of match to the vaccine strains. Conclusions This study contributes to the understanding of the circulation of influenza B viruses in Italy. We found a continuous co-circulation of both B lineages in the period 2004–2017, and determined that children were particularly vulnerable to Victoria-lineage influenza B virus infections. An influenza B lineage mismatch with the trivalent vaccine occurred in about two-thirds of cases.

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.

scholarly journals MOLECULAR CHARACTERIZATION OF INFLUENZA B VIRUS OUTBREAK ON A CRUISE SHIP IN BRAZIL 2012

2014 ◽  
Vol 56 (3) ◽  
pp. 185-189 ◽  
Author(s):  
Samanta Etel Treiger Borborema ◽  
Daniela Bernardes Borges da Silva ◽  
Kátia Corrêa Oliveira Silva ◽  
Margarete Aparecida Benega Pinho ◽  
Suely Pires Curti ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Disease Surveillance ◽  
Respiratory Illness ◽  
Control Measures ◽  
Influenza B Virus ◽  
Influenza B ◽  
Cruise Ship ◽  
Ha Gene ◽  
B Virus

In February 2012, an outbreak of respiratory illness occurred on the cruise ship MSC Armonia in Brazil. A 31-year-old female crew member was hospitalized with respiratory failure and subsequently died. To study the etiology of the respiratory illness, tissue taken at necropsy from the deceased woman and respiratory specimens from thirteen passengers and crew members with respiratory symptoms were analyzed. Influenza real-time RT-PCR assays were performed, and the full-length hemagglutinin (HA) gene of influenza-positive samples was sequenced. Influenza B virus was detected in samples from seven of the individuals, suggesting that it was the cause of this respiratory illness outbreak. The sequence analysis of the HA gene indicated that the virus was closely related to the B/Brisbane/60/2008-like virus, Victoria lineage, a virus contained in the 2011-12 influenza vaccine for the Southern Hemisphere. Since the recommended composition of the influenza vaccine for use during the 2013 season changed, an intensive surveillance of viruses circulating worldwide is crucial. Molecular analysis is an important tool to characterize the pathogen responsible for an outbreak such as this. In addition, laboratory disease surveillance contributes to the control measures for vaccine-preventable influenza.

scholarly journals The Evolutionary Dynamics of Human Influenza B Virus

2008 ◽  
Vol 66 (6) ◽  
pp. 655-663 ◽  
Author(s):  
Rubing Chen ◽  
Edward C. Holmes
Keyword(s):  
Evolutionary Dynamics ◽  
Influenza B Virus ◽  
Influenza B ◽  
Human Influenza ◽  
B Virus

scholarly journals The Epidemiology and Burden of Influenza B/Victoria and B/Yamagata Lineages in Kenya, 2012–2016

2019 ◽  
Vol 6 (10) ◽  
Author(s):  
Gideon O Emukule ◽  
Fredrick Otiato ◽  
Bryan O Nyawanda ◽  
Nancy A Otieno ◽  
Caroline A Ochieng ◽  
...  
Keyword(s):  
Respiratory Illness ◽  
Sub Saharan Africa ◽  
Influenza B Virus ◽  
Influenza B ◽  
Strain Component ◽  
Annual Range ◽  
B Virus ◽  
Sub Saharan ◽  
Vaccine Availability ◽  
The Impact

Abstract Background The impact of influenza B virus circulation in Sub-Saharan Africa is not well described. Methods We analyzed data from acute respiratory illness (ARI) in Kenya. We assessed clinical features and age-specific hospitalization and outpatient visit rates by person-years for influenza B/Victoria and B/Yamagata and the extent to which circulating influenza B lineages in Kenya matched the vaccine strain component of the corresponding season (based on Northern Hemisphere [October–March] and Southern Hemisphere [April–September] vaccine availability). Results From 2012 to 2016, influenza B represented 31% of all influenza-associated ARIs detected (annual range, 13–61%). Rates of influenza B hospitalization and outpatient visits were higher for <5 vs ≥5 years. Among <5 years, B/Victoria was associated with pneumonia hospitalization (64% vs 44%; P = .010) and in-hospital mortality (6% vs 0%; P = .042) compared with B/Yamagata, although the mean annual hospitalization rate for B/Victoria was comparable to that estimated for B/Yamagata. The 2 lineages co-circulated, and there were mismatches with available trivalent influenza vaccines in 2/9 seasons assessed. Conclusions Influenza B causes substantial burden in Kenya, particularly among children aged <5 years, in whom B/Victoria may be associated with increased severity. Our findings suggest a benefit from including both lineages when considering influenza vaccination in Kenya.

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.  

scholarly journals Influenza B Viruses Exhibit Lower Within-Host Diversity than Influenza A Viruses in Human Hosts

2019 ◽  
Vol 94 (5) ◽  
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

ABSTRACT Influenza B virus (IBV) undergoes seasonal antigenic drift more slowly than influenza A virus, 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 at the level of individual hosts. These processes have recently been described for influenza A virus, but little is known about the evolutionary dynamics of IBV during individual infections and transmission events. Here, we define the within-host evolutionary dynamics of IBV by sequencing virus populations from naturally infected individuals enrolled in a prospective, community-based cohort over 8,176 person-seasons of observation. Through analysis of high depth-of-coverage sequencing data from samples from 91 individuals with influenza B, we find that IBV 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 IBVs 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 the lower global evolutionary rate of IBV. IMPORTANCE The 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 virus, 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.

scholarly journals Recurring Influenza B Virus Infections in Seals

2013 ◽  
Vol 19 (3) ◽  
pp. 511-512 ◽  
Author(s):  
Rogier Bodewes ◽  
Danny Morick ◽  
Gerrie de Mutsert ◽  
Nynke Osinga ◽  
Theo Bestebroer ◽  
...  
Keyword(s):  
Influenza B Virus ◽  
Influenza B ◽  
Virus Infections ◽  
B Virus
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