Avian Influenza Or Bird Flu
The term "Bird Flu" is known to most of us, but we generally are not aware about the term 'avian influenza'. Both these terms actually refer to the same influenza, which results from a virus that is carried by birds. All forms of avian influenza or bird flu are not dangerous, but the highly pathogenic avian influenza or HPAI is a great matter of concern for most of the scientists as well as for the common man.
Recently, across the world, bird flu took the form of an epidemic and the HPAI is actually responsible for such occurrence. In this context we have to remember that influenza causing viruses for birds belongs to the category of influenza A. As all the sub classification of influenza, a virus that the birds hold as hosts, transmitted to human or other animal bodies. The avian influenza virus also belongs to the category of influenza A.
There are many types of viruses that have been named as human flu viruses but are clearly distinguished from that of their avian flu counterparts. Scientists have identified genetic aspects as most important factors that distinguish between these two types. PB2 or RNA polymerase and HA or hemagglutinin are two genetic factors that play the most important part in distinguishing between human and avian flu viruses. There are many subtypes of avian flu viruses but only four among those are mainly found in human bodies, namely the H7N7, H9N2, H5N1 and H7N3.
After witnessing devastating nature of bird flu, people have developed a conception that all forms of avian flu are fatal and infectious in nature. However, there is no scientific support behind such observation. Unique genetic construction of Pandemic flu viruses is mainly responsible for their infectious nature.
This type of virus comprises both avian influenza and some human influenza virus genes. It is due to this reason both H2N2 and H3N2 subtypes are infectious in nature and have the capacity to take shape of an epidemic. These two new types of viruses actually take swine as hosts and from there, these are transmitted to human body. When it comes to spreading of avian influenza virus, pigs act as intermediate hosts because genetic structure of pig cells help in proper assortment of various categories of influenza subtypes.
Compared to any other avian flu virus subtypes, the H5N1 type is most infectious in nature compared to any other flu virus. It becomes tough to confront this type of virus, because not much has been research about this virus. Thus, when the epidemic started, scientists were quite confused about finding ways to prevent and cure the virus, so that attack of this new kind of bird flu can be checked immediately. Unfortunately, most of such initial attempts proved to be futile. After sometime, vaccines were introduced to fight against the H5N1 subtypes but it is not available in all countries at the adequate amount. Thus, impact of recent bird flu attack, though has been controlled to some extent cannot entirely be eradicated from all affected nations.
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