scholarly journals Molecular detection of influenza A(H1N1)pdm09 viruses with M genes from human pandemic strains among Nigerian pigs, 2013–2015: implications and associated risk factors

2017 ◽  
Vol 145 (16) ◽  
pp. 3345-3360 ◽  
Author(s):  
O. A. ADEOLA ◽  
B. O. OLUGASA ◽  
B. O. EMIKPE
Keyword(s):  
Risk Factors ◽  
Influenza A ◽  
Influenza Viruses ◽  
Scan Statistics ◽  
Rt Pcr ◽  
Pandemic Virus ◽  
Influenza A H1n1 ◽  
Pandemic Strains ◽  
Associated Risk Factors ◽  
Ibadan Nigeria

SUMMARYIn the post-pandemic period, influenza A(H1N1)pdm09 virus has been detected in swine populations in different parts of the world. This study was conducted to determine the presence and spatial patterns of this human pandemic virus among Nigerian pigs and identify associated risk factors. Using a two-stage stratified random sampling method, nasal swab specimens were obtained from pigs in Ibadan, Nigeria during the 2013–2014 and 2014–2015 influenza seasons, and the virus was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Purified RT-PCR products were sequenced in both directions, and sequences were aligned using MUSCLE. Phylogenetic analysis was conducted in MEGA6. Purely spatial scan statistics and a spatial lag regression model were used to identify spatial clusters and associated risk factors. The virus was detected in both seasons, with an overall prevalence of 8·7%. Phylogenetic analyses revealed that the M genes were similar to those of pandemic strains which circulated in humans prior to and during the study. Cluster analysis revealed a significant primary spatial cluster (RR = 4·71, LLR = 5·66,P= 0·0046), while ‘hours spent with pigs (R2= 0·90,P= 0·0018)’ and ‘hours spent with pigs from different farms (R2= 0·91,P= 0·0001)’ were identified as significant risk factors (P< 0·05). These findings reveal that there is considerable risk of transmission of the pandemic virus, either directly from pig handlers or through fomites, to swine herds in Ibadan, Nigeria. Active circulation of the virus among Nigerian pigs could enhance its reassortment with endemic swine influenza viruses. Campaigns for adoption of biosecurity measures in West African piggeries and abattoirs should be introduced and sustained in order to prevent the emergence of a new influenza epicentre in the sub-region.

scholarly journals High frequency of cross-reacting antibodies against 2009 pandemic influenza A(H1N1) virus among the elderly in Finland

2010 ◽  
Vol 15 (5) ◽  
Author(s):  
N Ikonen ◽  
M Strengell ◽  
L Kinnunen ◽  
P Österlund ◽  
J Pirhonen ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Pandemic Influenza ◽  
Influenza A ◽  
Seasonal Influenza ◽  
H1n1 Virus ◽  
The Elderly ◽  
Influenza Viruses ◽  
Spanish Influenza ◽  
Pandemic Virus ◽  
Influenza A H1n1

Since May 2009, the pandemic influenza A(H1N1) virus has been spreading throughout the world. Epidemiological data indicate that the elderly are underrepresented among the ill individuals. Approximately 1,000 serum specimens collected in Finland in 2004 and 2005 from individuals born between 1909 and 2005, were analysed by haemagglutination-inhibition test for the presence of antibodies against the 2009 pandemic influenza A(H1N1) and recently circulating seasonal influenza A viruses. Ninety-six per cent of individuals born between 1909 and 1919 had antibodies against the 2009 pandemic influenza virus, while in age groups born between 1920 and 1944, the prevalence varied from 77% to 14%. Most individuals born after 1944 lacked antibodies to the pandemic virus. In sequence comparisons the haemagglutinin (HA) gene of the 2009 pandemic influenza A(H1N1) virus was closely related to that of the Spanish influenza and 1976 swine influenza viruses. Based on the three-dimensional structure of the HA molecule, the antigenic epitopes of the pandemic virus HA are more closely related to those of the Spanish influenza HA than to those of recent seasonal influenza A(H1N1) viruses. Among the elderly, cross-reactive antibodies against the 2009 pandemic influenza virus, which likely originate from infections caused by the Spanish influenza virus and its immediate descendants, may provide protective immunity against the present pandemic virus.

scholarly journals The emergence of oseltamivir-resistant pandemic influenza A(H1N1) 2009 virus amongst hospitalised immunocompromised patients in Scotland, November-December, 2009

2010 ◽  
Vol 15 (14) ◽  
Author(s):  
H Harvala ◽  
R Gunson ◽  
P Simmonds ◽  
A Hardie ◽  
S Bennett ◽  
...  
Keyword(s):  
Pandemic Influenza ◽  
Influenza A ◽  
H1n1 Pandemic ◽  
Immunocompromised Patients ◽  
Rt Pcr ◽  
Oseltamivir Resistance ◽  
Pandemic Virus ◽  
Hospitalised Patients ◽  
Influenza A H1n1 ◽  
H275y Mutation

To investigate the frequency of oseltamivir resistance in circulating strains of the 2009 influenza A(H1N1) pandemic virus in Scotland, 1,802 samples from 1,608 infected hospitalised patients were screened by the H275Y discriminatory RT-PCR. Among these, we identified 10 patients who developed the H275Y mutation. All of them were immunocompromised and were under treatment or had been treated previously with oseltamivir.

scholarly journals A multiplex one-step real-time RT-PCR assay for influenza surveillance

2011 ◽  
Vol 16 (7) ◽  
Author(s):  
I Huber ◽  
H Campe ◽  
D Sebah ◽  
C Hartberger ◽  
R Konrad ◽  
...  
Keyword(s):  
Real Time ◽  
High Throughput ◽  
Influenza A ◽  
Multiplex Assay ◽  
Influenza Viruses ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Rt Pcr ◽  
Influenza A H1n1 ◽  
One Step

For surveillance purposes real-time PCR assays for influenza viruses had to be adapted to the pandemic influenza A(H1N1)2009 strain. We combined published primers and probes for influenza A, influenza B and an internal amplification control with a detection system for influenza A(H1N1)2009 to set up a rapid, reliable, simple and cost-effective high-throughput multiplex one-step real-time RT-PCR. The workflow also includes automated sample preparation for high-throughput screening. The lower limit of detection of the multiplex assay was 3.5x102 RNA copies per PCR reaction. The diagnostic sensitivity of the multiplex assay was 87.7%, but increased to 99.4% for influenza-positive samples yielding Ct values of less than 34 cycles in the respective diagnostic assay. High specificity was confirmed by sequencing and correct detection of 15 reference samples from two quality assurance studies. The multiplex PCR was introduced for surveillance of samples from a network of general practitioners and paediatricians in Bavaria, Germany during the influenza pandemic of 2009. Comparison with surveillance data from reported cases proved the reliability of the multiplex assay for influenza surveillance programmes.

scholarly journals Influenza in hospitalized children in Ireland in the pandemic period and the 2010/2011 season: risk factors for paediatric intensive-care-unit admission

2013 ◽  
Vol 142 (9) ◽  
pp. 1826-1835 ◽  
Author(s):  
J. REBOLLEDO ◽  
D. IGOE ◽  
J. O'DONNELL ◽  
L. DOMEGAN ◽  
M. BOLAND ◽  
...  
Keyword(s):  
Risk Factors ◽  
Intensive Care Unit ◽  
Intensive Care ◽  
Paediatric Intensive Care Unit ◽  
Influenza A ◽  
Significant Risk ◽  
Influenza Viruses ◽  
Paediatric Intensive Care ◽  
Severe Illness ◽  
Influenza A H1n1

SUMMARYInfluenza causes significant morbidity and mortality in children. This study's objectives were to describe influenza A(H1N1)pdm09 during the pandemic, to compare it with circulating influenza in 2010/2011, and to identify risk factors for severe influenza defined as requiring admission to a paediatric intensive care unit (PICU). Children hospitalized with influenza during the pandemic were older, and more likely to have received antiviral therapy than children hospitalized during the 2010/2011 season. In 2010/2011, only one child admitted to a PICU with underlying medical conditions had been vaccinated. The risk of severe illness in the pandemic was higher in females and those with underlying conditions. In 2010/2011, infection with influenza A(H1N1)pdm09 compared to other influenza viruses was a significant risk factor for severe disease. An incremental relationship was found between the number of underlying conditions and PICU admission. These findings highlight the importance of improving low vaccination uptake and increasing the use of antivirals in vulnerable children.

scholarly journals Pandemic H1N1 2009 Influenza A Virus Induces Weak Cytokine Responses in Human Macrophages and Dendritic Cells and Is Highly Sensitive to the Antiviral Actions of Interferons

2009 ◽  
Vol 84 (3) ◽  
pp. 1414-1422 ◽  
Author(s):  
Pamela Österlund ◽  
Jaana Pirhonen ◽  
Niina Ikonen ◽  
Esa Rönkkö ◽  
Mari Strengell ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Influenza A Virus ◽  
Influenza A ◽  
H1n1 Virus ◽  
Influenza Viruses ◽  
Type I ◽  
Pandemic H1n1 ◽  
Pandemic Virus ◽  
Highly Sensitive ◽  
Influenza A H1n1

ABSTRACT In less than 3 months after the first cases of swine origin 2009 influenza A (H1N1) virus infections were reported from Mexico, WHO declared a pandemic. The pandemic virus is antigenically distinct from seasonal influenza viruses, and the majority of human population lacks immunity against this virus. We have studied the activation of innate immune responses in pandemic virus-infected human monocyte-derived dendritic cells (DC) and macrophages. Pandemic A/Finland/553/2009 virus, representing a typical North American/European lineage virus, replicated very well in these cells. The pandemic virus, as well as the seasonal A/Brisbane/59/07 (H1N1) and A/New Caledonia/20/99 (H1N1) viruses, induced type I (alpha/beta interferon [IFN-α/β]) and type III (IFN-λ1 to -λ3) IFN, CXCL10, and tumor necrosis factor alpha (TNF-α) gene expression weakly in DCs. Mouse-adapted A/WSN/33 (H1N1) and human A/Udorn/72 (H3N2) viruses, instead, induced efficiently the expression of antiviral and proinflammatory genes. Both IFN-α and IFN-β inhibited the replication of the pandemic (H1N1) virus. The potential of IFN-λ3 to inhibit viral replication was lower than that of type I IFNs. However, the pandemic virus was more sensitive to the antiviral IFN-λ3 than the seasonal A/Brisbane/59/07 (H1N1) virus. The present study demonstrates that the novel pandemic (H1N1) influenza A virus can readily replicate in human primary DCs and macrophages and efficiently avoid the activation of innate antiviral responses. It is, however, highly sensitive to the antiviral actions of IFNs, which may provide us an additional means to treat severe cases of infection especially if significant drug resistance emerges.

Molecular and serological investigations of the Influenza A(H1N1) 2009 pandemic virus in Turkey

2013 ◽  
Vol 202 (4) ◽  
pp. 277-284 ◽  
Author(s):  
Meral Akcay Ciblak ◽  
Mustafa Hasoksuz ◽  
Melis Kanturvardar ◽  
Serkan Asar ◽  
Selim Badur
Keyword(s):  
Influenza A ◽  
Pandemic Virus ◽  
Influenza A H1n1

scholarly journals Influenza A (H1N1) virus infection and TNF-308, IL6, and IL8 polymorphisms in Egyptian population: a case–control study

2019 ◽  
Vol 80 (1) ◽  
Author(s):  
Shaimaa Moustafa Elsayed ◽  
Omayma Mohamed Hassanein ◽  
Nagwa Hassan Ali Hassan
Keyword(s):  
Influenza A ◽  
Case Control Study ◽  
H1n1 Virus ◽  
Case Control ◽  
Severe Illness ◽  
Study Results ◽  
Influenza A H1n1 ◽  
Pandemic Strains ◽  
Study Participants ◽  
Control Study

Abstract Background The importance of influenza is increasing mainly because of the appearance of novel pandemic strains such as swine and avian. Each year, influenza has spread around the world causing about 250,000–500,000 deaths and more than 5 million cases of severe illness. The objective is as follows: evaluating the outcomes of patients with influenza A (H1N1) virus in relation to certain TNF-308, IL6, and IL8 polymorphisms and identifying the associated factors with the severe outcome. Subject and methods This is a case–control study. The cases were patients confirmed by real-time polymerase chain reaction (RT-PCR) to be influenza A (H1N1) virus infected. The controls were healthy individuals. Medical history and outcome of the disease was registered. In all study participants, polymorphisms of TNF rs1800629, IL6 rs18138879, and IL8 rs4073; odds ratio (OR); and the 95% confidence interval (95% CI) were calculated. Results Infection with influenza A (H1N1) virus was associated more with the following genotypes: TNF-308 AA (OR = 4.041; 95% CI = 1.215–13.4) and IL8 AA (OR = 3.273; 95% CI = 1.372–7.805). According to our study results, HCV (OR = 3.2, 95% CI 1.2–8.5), renal disease (OR = 3.4, 95% CI 0.9–13.6), cancer (OR = 3.1, 95% CI 0.3–31.1), TB (OR = 8.4, 95% CI 1.8–39.7), ICU (OR = 2.9, 95%1.2–7.1), and mortality (OR = 7.9, 95% CI 0.9–67.4) are considered as risk factors for influenza A (H1N1)-infected patients. Conclusions Our findings concluded that TNF-308 (AA) and IL8 (AA) polymorphisms may increase the susceptibility to be infected with H1N1influenza virus.

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.

Modeling and simulation of the spread of H1N1 flu with periodic vaccination

2015 ◽  
Vol 09 (01) ◽  
pp. 1650003 ◽  
Author(s):  
Islam A. Moneim
Keyword(s):  
Influenza A ◽  
Vaccination Strategy ◽  
Vaccination Rate ◽  
Influenza Viruses ◽  
Sirs Epidemic Model ◽  
Sirs Model ◽  
Influenza A H1n1 ◽  
Large Populations ◽  
Stability Results ◽  
Influenza H1n1

Influenza H1N1 has been found to exhibit oscillatory levels of incidence in large populations. Clear peaks for influenza H1N1 are observed in several countries including Vietnam each year [M. F. Boni, B. H. Manh, P. Q. Thai, J. Farrar, T. Hien, N. T. Hien, N. Van Kinh and P. Horby, Modelling the progression of pandemic influenza A (H1N1) in Vietnam and the opportunities for reassortment with other influenza viruses, BMC Med. 7 (2009) 43, Doi: 10.1186/1741-7015-7-43]. So it is important to study seasonal forces and factors which can affect the transmission of this disease. This paper studies an SIRS epidemic model with seasonal vaccination rate. This SIRS model has a unique disease-free solution (DFS). The value R0, the basic reproduction number is obtained when the vaccination is a periodic function. Stability results for the DFS are obtained when R0 < 1. The disease persists in the population and remains endemic if R0 > 1. Also when R0 > 1 existence of a nonzero periodic solution is proved. These results obtained for our model when the vaccination strategy is a non-constant time-dependent function.

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.

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