Avian Influenza is a viral disease of wild and domestic birds.
It can cause illness in poultry and humans.
Avian influenza (AI) is an infectious viral disease of birds often causing no obvious signs of infection. AI viruses can sometimes spread to domestic poultry and cause large-scale outbreaks of serious disease. Some of these AI viruses have also been reported to cross the species barrier and cause disease or subclinical infections in humans and in other mammals. Though it affects birds primarily poultry are very susceptible to housing the virus and can die in extremely large numbers. The mammals which could be infected include pigs, cats, horses, dogs, and even household ferrets as pets.
AI viruses are divided into two groups based on their ability to cause disease in poultry: high pathogenicity or low pathogenicity. Highly pathogenic viruses result in high death rates (up to 100% mortality within 48 hours) in some poultry species. Low pathogenicity viruses also cause outbreaks in poultry but are not generally associated with severe clinical disease.
Avian Influenza (Bird Flu)
Avian influenza (AI), commonly called the bird flu is a viral disease of birds which can be highly infectious to both animals and humans if contracted. Even though most avian influenza viruses do not infect humans it is possible. For instance, the H5N1 strain has caused serious infections and sometimes death in people. This report will discuss the etiological agent, characteristics of the pathogen, virulence factors, diagnosis, prognosis, treatment with vaccines, and some preventative measures for the avian influenza bird flu.
The etiological agent of avian influenza is a type A influenza virus known as H5N1.
According to the World Health Organization (WHO), the H5N1 virus subtype - a highly pathogenic AI virus- first infected humans in 1997 during a poultry outbreak in Hong Kong SAR, China. Since its widespread re-emergence in 2003 and 2004, this avian virus has spread from Asia to Europe and Africa and has become entrenched in poultry in some countries, resulting in millions of poultry infections, several hundred human cases, and many human deaths. (World Health Organization, 2011) The influenza virus is composed of a protein capsid and covered in an envelope. There are two types of projectiles on the virus, the first is hemagglutinin (the H in H5N1) the second projection is neuraminidase (the N in H5N1). Each projectile or spike allows attachment or detachment to human cells. H5N1 is a respiratory virus (Tortora, Funke, Case. eleventh edition). Humans can be infected with the avian influenza virus by either direct contact or very close contact with sick poultry. The WHO mentions a potential possibility of person to person contact there is very little evidence to prove the theory. Like some other emerging diseases the H5N1 in humans are not understood clearly. Though there is no evidence to prove the H5N1 virus can be transmitted to humans through properly prepared poultry and eggs a few human cases have been linked to raw portions of these foods.
Since the first avian influenza outbreak, in 1997, there has been concern that the influenza A (H5N1) virus might either mutate and adapt to allow efficient transmission during the infection of mammals or reassert its gene segments with human influenza viruses during the confection of a single host, resulting in a new virus that would be both highly lethal and transmissible from person to person. Such events are believed to have preceded the influenza pandemics of 1918, 1957, and 1968. Several lines of evidence indicate that the currently circulating influenza A (H5N1) viruses have in fact evolved to more virulent forms since 1997, with a higher mortality among human cases, different antigenic properties, a different internal gene