scholarly journals Mammalian-Transmissible H5N1 Influenza: Facts and Perspective

mBio ◽  
2012 ◽  
Vol 3 (2) ◽  
Author(s):  
Michael T. Osterholm ◽  
Nicholas S. Kelley
Keyword(s):  
Influenza A ◽  
Case Fatality Rate ◽  
Influenza Pandemic ◽  
Case Fatality ◽  
Influenza Viruses ◽  
Fatality Rate ◽  
Dual Use ◽  
H5n1 Influenza ◽  
Unpublished Studies ◽  
Medical Countermeasures

ABSTRACT Two recently submitted (but as yet unpublished) studies describe success in creating mutant isolates of H5N1 influenza A virus that can be transmitted via the respiratory route between ferrets; concern has been raised regarding human-to-human transmissibility of these or similar laboratory-generated influenza viruses. Furthermore, the potential release of methods used in these studies has engendered a great deal of controversy around publishing potential dual-use data and also has served as a catalyst for debates around the true case-fatality rate of H5N1 influenza and the capability of influenza vaccines and antivirals to impact any future unintentional or intentional release of H5N1 virus. In this report, we review available seroepidemiology data for H5N1 infection and discuss how case-finding strategies may influence the overall case-fatality rate reported by the WHO. We also provide information supporting the position that if an H5N1 influenza pandemic occurred, available medical countermeasures would have limited impact on the associated morbidity and mortality.

scholarly journals The European Union faces up to the threat of a pandemic: meeting at the DGV on the influenza A (H5N1) of the ad hoc group on communicable diseases Luxembourg 14 January 1998

1998 ◽  
Vol 3 (3) ◽  
pp. 25-6 ◽  
Author(s):  
J C Desenclos ◽  
R Manigat
Keyword(s):  
Influenza A ◽  
Case Fatality Rate ◽  
H5n1 Virus ◽  
Ad Hoc ◽  
Influenza Pandemic ◽  
Case Fatality ◽  
Fatality Rate ◽  
The European Union ◽  
High Case Fatality Rate ◽  
Influenza H5n1

The transmission of an avian influenza H5N1 virus to a child in Hong Kong in May 1997 followed by the occurrence of 17 other human cases with a high case fatality rate (6/18, 33%) suggested that an influenza pandemic could be imminent and led many Europea

scholarly journals Natural Variation Can Significantly Alter the Sensitivity of Influenza A (H5N1) Viruses to Oseltamivir

2006 ◽  
Vol 50 (11) ◽  
pp. 3809-3815 ◽  
Author(s):  
M. A. Rameix-Welti ◽  
F. Agou ◽  
P. Buchy ◽  
S. Mardy ◽  
J. T. Aubin ◽  
...  
Keyword(s):  
Influenza A ◽  
Influenza Pandemic ◽  
Fold Increase ◽  
Influenza Viruses ◽  
Control Measures ◽  
Inhibition Assay ◽  
Highly Pathogenic ◽  
H5n1 Influenza ◽  
The Impact

ABSTRACT Geographic spread of highly pathogenic avian H5N1 influenza viruses may give rise to an influenza pandemic. During the first months of a pandemic, control measures would rely mainly on antiviral drugs, such as the neuraminidase (NA) inhibitors oseltamivir and zanamivir. In this study, we compare the sensitivities to oseltamivir of the NAs of several highly pathogenic H5N1 viruses isolated in Asia from 1997 to 2005. The corresponding 50% inhibitory concentrations were determined using a standard in vitro NA inhibition assay. The Km for the substrate and the affinity for the inhibitor (Ki ) of NA were determined for a 1997 and a 2005 virus, using an NA inhibition assay on cells transiently expressing the viral enzyme. Our data show that the sensitivities of the NAs of H5N1 viruses isolated in 2004 and 2005 to oseltamivir are about 10-fold higher than those of earlier H5N1 viruses or currently circulating H1N1 viruses. Three-dimensional modeling of the N1 protein predicted that Glu248Gly and Tyr252His changes could account for increased sensitivity. Our data indicate that genetic variation in the absence of any drug-selective pressure may result in significant variations in sensitivity to anti-NA drugs. Although the clinical relevance of a 10-fold increase in the sensitivity of NA to oseltamivir needs to be investigated further, the possibility that sensitivity to anti-NA drugs could increase (or possibly decrease) significantly, even in the absence of treatment, underscores the need for continuous evaluation of the impact of genetic drift on this parameter, especially for influenza viruses with pandemic potential.

scholarly journals 2009 Influenza A (H1N1) in Panama: a disease affecting children with a benign course

2011 ◽  
Vol 5 (09) ◽  
pp. 664-668 ◽  
Author(s):  
Javier Nieto- Guevara ◽  
Nestor Sosa ◽  
Mariana Garcia ◽  
Alex Martinez ◽  
Marlene Castillo
Keyword(s):  
Pandemic Influenza ◽  
Influenza A ◽  
Case Fatality Rate ◽  
Case Fatality ◽  
Nasopharyngeal Swab ◽  
Fatality Rate ◽  
Female Ratio ◽  
Severe Acute Respiratory Infection ◽  
Influenza A H1n1 ◽  
Epidemiological Characteristics

Introduction: Pandemic Influenza A (H1N1) was identified as the major febrile respiratory illness worldwide during the year 2009.  We present a report of its clinical and epidemiological characteristics in children and adults in Panama.  Methodology: A descriptive study from the database of the Gorgas Memorial Institute is presented.   We included patients with severe acute respiratory infection in whom a nasopharyngeal swab was positive by real-time RT-PCR for 2009 Influenza A (H1N1) pandemic virus and negative for seasonal influenza A H1 and H3. Results: From 26 April 2009 to 11 January 2010, confirmed cases of pandemic 2009 Influenza A (H1N1) reached 806. The overall incident rate was 23.35 cases of pandemic influenza per 100,000 habitants, with the highest incidence found in the age group between 10 to 14 years of age (58.67 cases per 100,000 habitants).  The median age for the cases was 13 years (ages ranging from one day to 88 years) and 71% were from the Panama City Metropolitan Area.  The male/female ratio was 1:1 and 90% were managed as out-patients.   An influenza-like syndrome was the presenting diagnosis in 99% of the cases.  Fever and cough were the most frequent symptoms reported in all age groups. The case fatality rate was 0.3 cases per 100,000 habitants. Conclusion: The 2009 Influenza A (H1N1) outbreak affected mainly the pediatric population, had a low case fatality rate, and was the predominant virus circulating in Panama during the 2009/2010 flu season

scholarly journals Age-specific infection and death rates for human A(H5N1) avian influenza in Egypt

2009 ◽  
Vol 14 (18) ◽  
Author(s):  
J P Dudley
Keyword(s):  
Influenza A ◽  
Case Fatality Rate ◽  
Case Fatality ◽  
Age Group ◽  
Fatality Rate ◽  
Death Rates ◽  
H5n1 Avian Influenza ◽  
Human H5n1 ◽  
Sex Biases ◽  
Age And Sex

The age-specific infection and death profiles among confirmed human cases of influenza A(H5N1) infection in Egypt differ markedly from those recorded in other countries. The case fatality rate among human H5N1 cases in Egypt is 34%, versus an average of 66% in other countries. In Egypt, children younger than 10 years comprise 48% of reported cases, nearly twice the global average of approximately 25%, and no H5N1 fatalities have been confirmed among individuals in this age group as of 23 April 2009. Females outnumber males among confirmed H5N1 cases by a factor of nearly 2:1, and 90% of reported fatalities in Egypt have been females. The evident age and sex biases in morbidity and mortality among H5N1 cases in Egypt are phenomena that warrant further investigation and analysis.

scholarly journals Growth Determinants for H5N1 Influenza Vaccine Seed Viruses in MDCK Cells

2008 ◽  
Vol 82 (21) ◽  
pp. 10502-10509 ◽  
Author(s):  
Shin Murakami ◽  
Taisuke Horimoto ◽  
Le Quynh Mai ◽  
Chairul A. Nidom ◽  
Hualan Chen ◽  
...  
Keyword(s):  
Cell Line ◽  
Influenza A ◽  
Mdck Cells ◽  
Influenza Pandemic ◽  
Influenza Viruses ◽  
Vaccine Production ◽  
Efficient Manner ◽  
Short Supply ◽  
Promising Alternative ◽  
H5n1 Influenza

ABSTRACT H5N1 influenza A viruses are exacting a growing human toll, with more than 240 fatal cases to date. In the event of an influenza pandemic caused by these viruses, embryonated chicken eggs, which are the approved substrate for human inactivated-vaccine production, will likely be in short supply because chickens will be killed by these viruses or culled to limit the worldwide spread of the infection. The Madin-Darby canine kidney (MDCK) cell line is a promising alternative candidate substrate because it supports efficient growth of influenza viruses compared to other cell lines. Here, we addressed the molecular determinants for growth of an H5N1 vaccine seed virus in MDCK cells, revealing the critical responsibility of the Tyr residue at position 360 of PB2, the considerable requirement for functional balance between hemagglutinin (HA) and neuraminidase (NA), and the partial responsibility of the Glu residue at position 55 of NS1. Based on these findings, we produced a PR8/H5N1 reassortant, optimized for this cell line, that derives all of its genes for its internal proteins from the PR8(UW) strain except for the NS gene, which derives from the PR8(Cambridge) strain; its N1 NA gene, which has a long stalk and derives from an early H5N1 strain; and its HA gene, which has an avirulent-type cleavage site sequence and is derived from a circulating H5N1 virus. Our findings demonstrate the importance and feasibility of a cell culture-based approach to producing seed viruses for inactivated H5N1 vaccines that grow robustly and in a timely, cost-efficient manner as an alternative to egg-based vaccine production.

scholarly journals 1373Severe acute respiratory infection with high mortality rate in Sana'a city, 2018-2019 Yemen

2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Manal Mahsoon ◽  
Yasser Ghaleb ◽  
Riham Al-dubaiee ◽  
Mohamed Al Amad
Keyword(s):  
Respiratory Infection ◽  
Acute Respiratory Infection ◽  
Case Fatality Rate ◽  
Case Fatality ◽  
Control Program ◽  
Case Definition ◽  
Influenza Viruses ◽  
P Value ◽  
Fatality Rate ◽  
Severe Acute Respiratory Infection

Abstract Background The burden of influenza and severe acute respiratory infection (SARI) in conflict countries such as Yemen is exacerbated due to limited resources and the collapse of the health system. The aims are to describe epidemiology of SARI, determine influenza detection and case fatality rates among SARI patients. Methods We used a descriptive analytical study design. All SARI patients who meet WHO case definition during 2018-2019 from Sana'a city were included. Nasopharyngeal samples were examined by polymerase chain reaction. A soft copy of data that collected by surveillance staff was obtained from the National Influenza Control Program (NICP). Case fatality rate and detection rate were calculated and P value < 0.05 used for statistical significant. Results 1447 SARI patients were reported: 73% males, 54% aged 15- < 50 years. Comorbidity was among 27% (387) of them: (57% cardio-vascular diseases and 50% diabetes). Samples of 934 (64%) SARI patients were tested and influenza viruses were detected in 141 (15%) patients (13% type A and 2% type B). Higher influenza viruses were detected in winter months (November – February) (17% vs 9%, P < 0.001). Overall SARI fatality rate was 19% (276), significantly higher among patients with comorbidity (26% vs 16%, P < 0.001) confirmed influenza (30% Vs 15%, P value < 0.001) and not receiving antiviral (51% vs 17%, P < 0.001) than relevant groups. Conclusions SARI patients in Yemen had a high case-fatality rate particularly SARI patients with confirmed influenza. Introduce influenza vaccination for the risk group should be considered. Key messages Influenza and SARI cases are high in Yemen and progress to death.

scholarly journals Clinical aspects of influenza A(H1N1)pdm09 cases reported during the pandemic in Brazil, 2009-2010

2015 ◽  
Vol 13 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Érika Valeska Rossetto ◽  
Expedito José de Albuquerque Luna
Keyword(s):  
Influenza Virus ◽  
Pregnant Women ◽  
Influenza A ◽  
Case Fatality Rate ◽  
Case Fatality ◽  
Clinical Aspects ◽  
Fatality Rate ◽  
Women Health ◽  
Influenza A H1n1 ◽  
Common Sign

ABSTRACT Objective: To describe the clinical aspects of cases of influenza A(H1N1)pdm09 in Brazil. Methods: A descriptive study of cases reported in Sistema de Informação de Agravos de Notificação (SINAN), 2009-2010. Results: As the final classification, we obtained 53,797 (56.79%) reported cases confirmed as a new influenza virus subtype, and 40,926 (43.21%) cases discarded. Fever was the most common sign, recorded in 99.74% of the confirmed and 98.92% of the discarded cases. Among the confirmed cases, the presence of comorbidities was reported in 32.53%, and in 38.29% of the discarded cases. The case fatality rate was 4.04%; 3,267 pregnant women were confirmed positive for influenza A new viral subtype and 2,730 of them were cured. The case fatality rate of pregnant women was 6.88%. Conclusion: The findings suggested concern of the health system with pregnant women, and patients with comorbidities and quality of care may have favored a lower mortality. We recommend that, when caring for patients with severe respiratory symptoms, with comorbidities, or pregnant women, health professionals should consider the need for hospital care, as these factors make up a worse prognosis of infection by the pandemic influenza virus.

Pandemic influenza A (H1N1) virus infection and avian influenza A (H5N1) virus infection: a comparative analysisThis paper is one of a selection of papers published in this special issue entitled “Second International Symposium on Recent Advances in Basic, Clinical, and Social Medicine” and has undergone the Journal's usual peer review process.

2010 ◽  
Vol 88 (4) ◽  
pp. 575-587 ◽  
Author(s):  
Christine Korteweg ◽  
Jiang Gu
Keyword(s):  
Virus Infection ◽  
Influenza A ◽  
Peer Review Process ◽  
Influenza Pandemic ◽  
H1n1 Influenza ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
H5n1 Influenza ◽  
Influenza A H1n1 ◽  
2009 H1n1

The 2009 H1N1 and H5N1 influenza viruses are newly (re-) emerged influenza A viruses (2009 A(H1N1) and A(H5N1), respectively) that have recently posed tremendous health threats in many regions worldwide. With the 2009 outbreak of H1N1 influenza A, the world witnessed the first influenza pandemic of the 21st century. The disease has rapidly spread across the entire globe, and has resulted in hundreds of thousands of cases with confirmed infection. Although characterized by high transmissibility, the virulence and fatality of the 2009 A(H1N1) influenza virus have thus far remained relatively low. The reverse holds true for A(H5N1) influenza; at a fatality rate that exceeds 60%, it is known to cause severe damage to the human respiratory system, but is not presently capable of efficient transmission from human to human. Apart from the clear differences between the two types of influenza, there are some significant similarities that warrant attention. In particular, the more severe and fatal 2009 A(H1N1) influenza cases have shown symptoms similar to those reported in cases of A(H5N1) influenza. Histopathological findings for these cases, to the extent available, also appear to have similarities for both diseases in terms of damage and severity. Here we review important recent publications in this area, and we discuss some of the key commonalities and contrasts between the two influenza A types in terms of their biology, origins, clinical features, pathology and pathogenesis, and receptors and transmissibility.

scholarly journals Clinical Outcome of Patients Hospitalized in a Tertiary Care Hospital of Nepal with Confirmed Influenza A/pdm 09(H1N1) in 2018/2019

2020 ◽  
Vol 18 (2) ◽  
pp. 196-200
Author(s):  
Upasana Acharya ◽  
Subhash Prasad Acharya
Keyword(s):  
Influenza A ◽  
Case Fatality Rate ◽  
Tertiary Care Hospital ◽  
Average Length ◽  
Tertiary Care ◽  
Case Fatality ◽  
Care Hospital ◽  
Fatality Rate ◽  
Hospital System ◽  
Average Length Of Stay

Background: It is important to monitor the cases affected by Influenza A/pdm09 as it is difficult to predict the behavior of Influenza A/pdm09 virus as a seasonal influenza. This study aimed to measure the clinical outcomes of patients with Influenza A/pdm 09 in a tertiary care hospital of Nepal in post pandemic period.Methods: A retrospective study was conducted in a tertiary care hospital of central Nepal to record the confirmed cases of Influenza A/pdm 09 from April 2018 to March 2019.The medical records of those patients whose throat sample had been sent to laboratory for testing Influenza A/pdm 09 were referred. The outcomes were then abstracted from the hospital system/medical record department.Results: Among 141 influenza suspected cases, 35.5%(N=50) were Influenza A/Pdm 09 positive. Both male and female were equal in distribution (N=25). Most positive cases were from the age group of 15-64 yrs. Out of total,72 %( N=36) with Influenza A/pdm 09 were discharged after treatment whereas case fatality rate was 22 %( N=11). Twenty-one positive cases were admitted in intensive care unit in which 52.4% expired. The average length of stay in I.C.U and mechanical ventilation were 6.4 days and 5.8 days respectively.Conclusions: This study in post pandemic period in Nepal shows the outcomes of patients with confirmed influenza A/pdm 09 in a year time period with comparably high case fatality rate. Keywords: Influenza A/pdm 09; Nepal; post pandemic, retrospective

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