Bird Flu, more properly called avian influenza, is an infectious disease that primarily affects birds but can also infect several kinds of mammal, including humans. Characterized by rapid prevalence, avian influenza has a variety of symptoms, ranging from simple to lethal.
Many species of wild bird – particularly migratory waterfowl, and, especially, ducks - seem able to carry bird flu without coming to any apparent harm, but infection with avian influenza causes other species, including domestic chickens, turkeys and geese, to become seriously ill. In poultry, the sickness caused by bird flu comes in two different types, one mild, widespread and barely noticeable, the other uncommon, deadly and very difficult to overlook. The incubation period of avian influenza ranges from 1 to 7 days. It is worth mentioning that the recent Bird Flu outbreaks in South East Asia and some European countries (like Turkey), as well as Iraq, are basically attributed to the direct contact with domestic, migratory and water birds.
The avian influenza A encompasses numerous subclasses and strains (15 strains so far), undergoing several genetic mutations and leading up to the appearance of several avian epidemics in South East Asia, the Americas, and, recently, Russia. These viral strains have been reduced to one stain (H5N1), which can affect several mammals, including humans. All bird species are prone to the H5N1 infection, but at varying degrees. At present, several spots around the world are hit by H5N1 outbreaks, leading up to the death and culling of millions of birds.
Besides, a number of humans, those in contact with infected birds, have been detected to be carriers of the virus. The contact with the live infected birds, either direct or indirect, is considered the main cause of infection. The virus could be transmitted through the birds' mouth secretions and excretion. Human infection could also caused by the contamination of the tools or clothes of the workers at poultry farms with the virus included in the birds' secretions and wastes. The virus can live for relatively long time in low-temperature environments.
The Bird Flu virus, in itself, could be not that dangerous. The danger essentially lies in the virus mutation, causing it to be transmitted from human to human, thus leading up rapid prevalence amongst people, from one place to another, such like the epidemics that afflicted the world during the 20th century, bringing about massive death tolls, amounting to millions in many spots around the world. Among these epidemics are:
the outbreak of the Spanish influenza, in 1918-1919,
the outbreak of the Asian influenza, in 1957-1958,
and the outbreak of Hong Kong influenza, in 1968-1969.
Considering the enormity of the epidemics afflicting the world in the course of the 20th century, ending up of colossal death tolls, and in light of the current world circumstances, which are quite ready for the appearance of a new epidemic, giving way, according to health experts, to the death of 2 to 4.7 million people, there has been an global response, under the auspices of the World Health Organization (WHO), aiming to make good use of the local, regional and international capacities in face of the epidemic. Such early preparation, based upon the statistics recorded in some Asian and European countries, would enable us to avoid and control the epidemic, as well as setting the proper plans to do so.