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A SPR Aptasensor for Detection of Avian Influenza Virus H5N1  [PDF]
Hua Bai,Ronghui Wang,Billy Hargis,Huaguang Lu,Yanbin Li
Sensors , 2012, DOI: 10.3390/s120912506
Abstract: Rapid and specific detection of avian influenza virus (AIV) is urgently needed due to the concerns over the potential outbreaks of highly pathogenic H5N1 influenza in animals and humans. Aptamers are artificial oligonucleic acids that can bind specific target molecules, and show comparable affinity for target viruses and better thermal stability than monoclonal antibodies. The objective of this research was to use a DNA-aptamer as the specific recognition element in a portable Surface Plasmon Resonance (SPR) biosensor for rapid detection of AIV H5N1 in poultry swab samples. A SPR biosensor was fabricated using selected aptamers that were biotinylated and then immobilized on the sensor gold surface coated with streptavidin via streptavidin-biotin binding. The immobilized aptamers captured AIV H5N1 in a sample solution, which caused an increase in the refraction index (RI). After optimizing the streptavidin and aptamer parameters, the results showed that the RI value was linearly related (R2 = 0.99) to the concentration of AIV in the range of 0.128 to 1.28 HAU. Negligible signal ( < 4% of H5N1) was observed from six non-target AIV subtypes. The AIV H5N1 in poultry swab samples with concentrations of 0.128 to 12.8 HAU could be detected using this aptasensor in 1.5 h.
Avian Influenza  [PDF]
Tsung-Zu Wu,Li-Min Huang
Chang Gung Medical Journal , 2005,
Abstract: Influenza is an old disease but remains vital nowadays. Three types of influenza viruses,namely A, B, C, have been identified; among them influenza A virus has pandemic potential.The first outbreak of human illness due to avian influenza virus (H5N1) occurred in1997 in Hong Kong with a mortality of 30%. The most recent outbreak of the avian influenzaepidemic has been going on in Asian countries since 2003. As of March 2005, 44 incidentalhuman infections and 32 deaths have been documented. Human influenza viruses differwith other avian influenza viruses on the choice of cellular receptors. Avian influenzaviruses bind to cell-surface glycoproteins or glycolipids containing terminal sialyl-galactosylresidues linked by 2-3-linkage [Neu5Ac(α2-3)Gal], whereas human viruses, including theearliest available isolates from the 1957 and 1968 pandemics, bind to receptors that containterminal 2-6-linked sialyl-galactosyl moieties [Neu5Ac(α2-6)Gal]. Recent evidence suggeststhat human bronchial ciliated epithelial cells contain Neu5Ac(α2-3)Gal and can beinfected with avian influenza viruses. Nevertheless, avian influenza viruses can not infectnon-ciliated bronchial epithelial cells. Hence, adaptation of the avian influenza virus to nonciliatedcells is a prerequisite for a pandemic virus to emerge. Biological behaviors ofinfluenza viruses indicate that once a pandemic virus emerges, isolation is not likely to containthis epidemic. A specific vaccine against the pandemic strain will not be available until6 to 12 months after the inception of the pandemic. Judicious use of antiviral agents andstringent disease control measures are imperative to decrease the impact of a future pandemic.
Rapid Estimation of Binding Activity of Influenza Virus Hemagglutinin to Human and Avian Receptors  [PDF]
Yang Cao,Xiaoying Koh,Libo Dong,Xiangjun Du,Aiping Wu,Xilai Ding,Hongyu Deng,Yuelong Shu,Jianzhu Chen,Taijiao Jiang
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0018664
Abstract: A critical step for avian influenza viruses to infect human hosts and cause epidemics or pandemics is acquisition of the ability of the viral hemagglutinin (HA) to bind to human receptors. However, current global influenza surveillance does not monitor HA binding specificity due to a lack of rapid and reliable assays. Here we report a computational method that uses an effective scoring function to quantify HA-receptor binding activities with high accuracy and speed. Application of this method reveals receptor specificity changes and its temporal relationship with antigenicity changes during the evolution of human H3N2 viruses. The method predicts that two amino acid differences at 222 and 225 between HAs of A/Fujian/411/02 and A/Panama/2007/99 viruses account for their differences in binding to both avian and human receptors; this prediction was verified experimentally. The new computational method could provide an urgently needed tool for rapid and large-scale analysis of HA receptor specificities for global influenza surveillance.
Rapid Detection of Highly Pathogenic Avian Influenza H5N1 Virus by TaqMan Reverse Transcriptase-Polymerase Chain Reaction  [PDF]
B.P. Shankar,R.N.S. Gowda,B. Pattnaik,B.H. Manjunath Prabhu
International Journal of Poultry Science , 2009,
Abstract: Highly pathogenic Avian Influenza (AI) H5N1 viruses have been spreading from Asia since late 2003. Early detection and classification are paramount for control of the disease because these viruses are lethal to birds and have caused fatalities in humans. Here we describe a TaqMan Reverse Transcriptase-Polymerase Chain Reaction Assay for rapid detection of Avian Influenza virus and for H5 subtyping by targeting HA gene of AI viruses. The assay was highly sensitive than RT-PCR and virus isolation in chick embryos. In the present study all samples (field samples) which are positive for HI and RT-PCR were tested by using TaqMan Reverse Transcriptase-Polymerase Chain Reaction Assay for reconfirmation. AI viruses (H5N1) were detected from nine samples which are received from Maharashtra during Avian influenza outbreak in India in 2006. Real-Time PCR assays was also conducted for detection of viral genome in different organs of experimental infected chickens revealed presence of the virus in all organs with high virus concentration in brain, heart, intestine and cloaca. This test allows definitive confirmation of an AI virus as H5 within hours, which is crucial for rapid implementation of control measures in the event of an outbreak.
Excessive Cytokine Response to Rapid Proliferation of Highly Pathogenic Avian Influenza Viruses Leads to Fatal Systemic Capillary Leakage in Chickens  [PDF]
Saya Kuribayashi, Yoshihiro Sakoda, Takeshi Kawasaki, Tomohisa Tanaka, Naoki Yamamoto, Masatoshi Okamatsu, Norikazu Isoda, Yoshimi Tsuda, Yuji Sunden, Takashi Umemura, Noriko Nakajima, Hideki Hasegawa, Hiroshi Kida
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068375
Abstract: Highly pathogenic avian influenza viruses (HPAIVs) cause lethal infection in chickens. Severe cases of HPAIV infections have been also reported in mammals, including humans. In both mammals and birds, the relationship between host cytokine response to the infection with HPAIVs and lethal outcome has not been well understood. In the present study, the highly pathogenic avian influenza viruses A/turkey/Italy/4580/1999 (H7N1) (Ty/Italy) and A/chicken/Netherlands/2586/2003 (H7N7) (Ck/NL) and the low pathogenic avian influenza virus (LPAIV) A/chicken/Ibaraki/1/2005 (H5N2) (Ck/Ibaraki) were intranasally inoculated into chickens. Ty/Italy replicated more extensively than Ck/NL in systemic tissues of the chickens, especially in the brain, and induced excessive mRNA expression of inflammatory and antiviral cytokines (IFN-γ, IL-1β, IL-6, and IFN-α) in proportion to its proliferation. Using in situ hybridization, IL-6 mRNA was detected mainly in microglial nodules in the brain of the chickens infected with Ty/Italy. Capillary leakage assessed by Evans blue staining was observed in multiple organs, especially in the brains of the chickens infected with Ty/Italy, and was not observed in those infected with Ck/NL. In contrast, LPAIV caused only local infection in the chickens, with neither apparent cytokine expression nor capillary leakage in any tissue of the chickens. The present results indicate that an excessive cytokine response is induced by rapid and extensive proliferation of HPAIV and causes fatal multiple organ failure in chickens.
Avian Influenza Virus: The Threat of A Pandemic  [PDF]
Shih-Cheng Chang,Yi-Ying Cheng,Shin-Ru Shih
Chang Gung Medical Journal , 2006,
Abstract: The 1918 influenza A virus pandemic caused a death toll of 40~50 million. Currently,because of the widespread dissemination of the avian influenza virus (H5N1), there is a highrisk of another pandemic. Avian species are the natural hosts for numerous subtypes ofinfluenza A viruses; however, the highly pathogenic avian influenza virus (HPAI) is not onlyextremely lethal to domestic avian species but also can infect humans and cause death. Thisreview discusses why the avian influenza virus is considered the most likely candidate forthe first flu pandemic of the 21st century
Avian Influenza infection in Human
Mohan. M,Trevor Francis Fernandez and Feroz Mohammed.M.S.
Veterinary World , 2008,
Abstract: Outbreaks caused by the H5N1 strain are presently of the greatest concern for human health. In assessing risks to human health, it is important to know exactly which avian virus strains are causing the outbreaks in birds.All available evidence points to an increased risk of transmission to humans when outbreaks of highly pathogenic avian H5N1 influenza are widespread in poultry. There is mounting evidence that this strain has a unique capacity to jump the species barrier and cause severe disease, with high mortality, in humans. There is no evidence, to date that efficient human to human transmission of H5N1 strain has occurred and very often. Efficient transmission among humans is a key property of pandemic strains and a property that the avian H5N1 and H9N2 viruses apparently lacked. The biological and molecular basis for effective aerosol transmission among humans is not known. The virus can improve its transmissibility among humans via two principal mechanisms. The first is a “reassortment” event, in which genetic material is exchanged between human and avian viruses during co-infection of a human or pig.Reassortment could result in a fully transmissible pandemic virus, announced by a sudden surge of cases with explosive spread. The second mechanism is a more gradual process of adaptive mutation, whereby the capability of the virus to bind to human cells increases during subsequent infections of humans. Adaptive mutation, expressed initially as small clusters of human cases with some evidence of human-to-human transmission, would probably give the world some time to take defensive action, if detected sufficiently early. As the number of human infections grows, the risk increases that a new virus subtype could emerge, triggering an influenza pandemic. Humans as well as swine must now be considered a potential mixing vessel for the generation of such a virus. This link between widespread infection in poultry and increased risk of human infection is being demonstrated right now in Asia. However, urgent control of all outbreaks of avian influenza in birds - even when caused by a strain of low pathogenicity- is of utmost importance. Research has shown that certain, avian influenza virus strains, usually of low pathogenicity can rapidly Avian Influenza infection in Human mutate (within 6 to 9 months) into a highly pathogenic strain if allowed to circulate in poultry populations. Altogether, more than half of the laboratoryconfirmed cases have been fatal. H5N1 avian influenza in humans is still a rare disease, but a severe one that must be closely watched a
Avian influenza: an osteopathic component to treatment  [cached]
Hruby Raymond J,Hoffman Keasha N
Osteopathic Medicine and Primary Care , 2007, DOI: 10.1186/1750-4732-1-10
Abstract: Avian influenza is an infection caused by the H5N1 virus. The infection is highly contagious among birds, and only a few known cases of human avian influenza have been documented. However, healthcare experts around the world are concerned that mutation or genetic exchange with more commonly transmitted human influenza viruses could result in a pandemic of avian influenza. Their concern remains in spite of the fact that the first United States vaccine against the H5N1 virus was recently approved. Under these circumstances the fear is that a pandemic of avian influenza could result in the kind of mortality that was seen with the Spanish influenza pandemic of 1918–1919, where the number of deaths was estimated to be as high as 40 million people. Retrospective data gathered by the American Osteopathic Association shortly after the 1918–1919 influenza pandemic have suggested that osteopathic physicians (DOs), using their distinctive osteopathic manipulative treatment (OMT) methods, observed significantly lower morbidity and mortality among their patients as compared to those treated by allopathic physicians (MDs) with standard medical care available at the time. In light of the limited prevention and treatment options available, it seems logical that a preparedness plan for the treatment of avian influenza should include these OMT procedures, provided by DOs and other healthcare workers capable of being trained to perform these therapeutic interventions. The purpose of this paper is to discuss the characteristics of avian influenza, describe the success of DOs during the 1918–1919 Spanish influenza pandemic, describe the evidence base for the inclusion of OMT as part of the preparedness plan for the treatment of avian influenza, and describe some of the specific OMT procedures that could be utilized as part of the treatment protocol for avian influenza patients.
Molecular patterns of avian influenza A viruses
Zheng Kou,FuMin Lei,ShengYue Wang,YanHong Zhou,TianXian Li
Chinese Science Bulletin , 2008, DOI: 10.1007/s11434-008-0236-2
Abstract: Avian influenza A viruses could get across the species barrier and be fatal to humans. Highly pathogenic avian influenza H5N1 virus was an example. The mechanism of interspecies transmission is not clear as yet. In this research, the protein sequences of 237 influenza A viruses with different subtypes were transformed into pseudo-signals. The energy features were extracted by the method of wavelet packet decomposition and used for virus classification by the method of hierarchical clustering. The clustering results showed that five patterns existed in avian influenza A viruses, which associated with the phenotype of interspecies transmission, and that avian viruses with patterns C and E could across species barrier and those with patterns A, B and D might not have the abilities. The results could be used to construct an early warning system to predict the transmissibility of avian influenza A viruses to humans.
Avian influenza : a review article
A. Yalda,H. Emadi1,M. Haji Abdolbaghi
Tehran University Medical Journal , 2006,
Abstract: The purpose of this paper is to provides general information about avian influenza (bird flu) and specific information about one type of bird flu, called avian influenza A (H5N1), that has caused infections in birds in Asia and Europe and in human in Asia. The main materials in this report are based on the World Health Organization (WHO) , world organization for animal health (OIE) , food and agriculture organization of the united nations (FAO) information and recommendations and review of the published literature about avian influenza. Since December 2003, highly pathogenic H5N1 avian influenza viruses have swept through poultry populations across Asia and parts of Europe. The outbreaks are historically unprecedented in scale and geographical spread. Their economic impact on the agricultural sector of the affected countries has been large. Human cases, with an overall fatality rate around 50%, have also been reported and almost all human infections can be linked to contact with infected poultry. Influenza viruses are genetically unstable and their behaviour cannot be predicted so the risk of further human cases persists. The human health implications have now gained importance, both for illness and fatalities that have occurred following natural infection with avian viruses, and for the potential of generating a re-assortant virus that could give rise to the next human influenza pandemic.
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