To the Editor: Aquatic birds form a natural reservoir of avian influenza viruses from which new human and animal influenza viruses originate. After initial detection in 2010 in China, a new highly pathogenic avian influenza (HPAI) virus of the H5N8 subtype reemerged in ducks in South Korea in 2014 (1,2). The hemagglutinin gene of this virus was distantly related to those of H5N1 subtypes that h...

Comparisons of residues between sub-types of influenza virus is increasingly used to assess the zoonotic potential of a circulating strain and for comparative studies across subtypes. An analysis of N-terminal cleavage sites for thirteen subtypes of influenza A hemagglutinin (HA) sequences, has previously been described by Nobusawa and colleagues. We have expanded this analysis for the eighteen...

We developed and evaluated a multiplex branched DNA assay for the detection and subtyping of avian influenza (AI) virus strains. The assay successfully detected all 94 AI virus strains of 15 different hemagglutinin (HA) subtypes tested while simultaneously differentiating 24 North American H5, 11 Eurasian H5, and 11 H7 strains. Our study demonstrates for the first time that a branched DNA metho...

The rapid outbreak of the highly pathogenic H5N1 avian influenza virus and its transmission to humans have induced world-wide fears of a new influenza pandemic. The most effective method for the reduction of the impact of such a pandemic would be prophylaxis with a safe and effective vaccine, as well as anti-viral materials. In this study, we generated the specific antibodies 'immunoglobulin yo...

The H5N1 influenza A viruses have circulated widely in the avian population for 10 years with only sporadic infection of humans observed and no sustained human to human transmission. Vaccination against potential pandemic strains is one strategy in planning for future influenza pandemics; however, the success of live attenuated vaccines for H5N1 has been limited, due to poor replication in the ...

The current definitions of high-pathogenicity avian influenza (HPAI), formulated over 10 years ago, were aimed at including viruses that were overtly virulent in in vivo tests and those that had the potential to become virulent. At that time the only virus known to have mutated to virulence was the one responsible for the 1983-84 Pennsylvania epizootic. The mechanism involved has not been seen ...

Sequence analysis of the endoproteolytic cleavage site within the hemagglutinin (HA) precursor protein HA(0) is fundamental for studies of the molecular biology of influenza A viruses, in particular, for molecular pathotyping of subtype H5 and H7 isolates. A current problem for routine diagnostics is the emergence of new strains of the H5 or H7 subtype or even other subtypes which escape detect...

Introduction of novel inactivated oil-emulsion vaccines against different strains of prevailing and emerging low pathogenic avian influenza (LPAI) viruses is not an economically viable option for poultry. Engineering attenuated Salmonella Gallinarum (S. Gallinarum) vaccine delivering H5 LPAI antigens can be employed as a bivalent vaccine against fowl typhoid and LPAI viruses, while still offeri...

Avian influenza (AI) viruses are Type A influenza viruses of the Orthomyxoviridae family. There are 15 subtypes of the virus widespread in migratory waterfowl throughout the world. It has become increasingly evident that some low pathogenic avian influenza (LPAI) H5 or H7 viruses have the capacity to mutate into the more virulent strains that cause extensive economic losses and high mortality. ...

Avian influenza (AI) and Newcastle disease (ND) affect various avian species, especially domestic poultry , and are caused by type A orthomyxoviruses and type 1 avian paramyxoviruses, respectively. 1,2 Clinical manifestations of such infections vary with the virus strain, the host species, and the presence or absence of secondary environmental factors or exacerbating agents. In domestic poultry...