why bird flu can kill people? 40分
why bird flu can kill people?
- 理學士Lv 61 decade agoFavorite Answer
Avian flu (also bird flu, avian influenza, bird influenza), means flu from viruses adapted to birds, but is sometimes mistakenly used to refer to both other flu subsets and the viruses that cause them. (Example: from any flu virus rather than ones adapted to birds, e.g. Dog flu, Horse flu, Human flu, Swine flu), or (also incorrectly) even the virus itself.
All known avian flu viruses belong to the species of virus called Influenza A virus. All subtypes (but not all strains of all subtypes) of Influenza A virus are adapted to birds, which is why for many purposes avian flu virus is the Influenza A virus (note that the A does not stand for avian).
Avian flu viruses are noninfectious for most species. When they are infectious they are usually asymptomatic, so the carrier does not have any disease from it. Thus while infected with an avian flu virus, the animal doesn't have a "flu&qu ot;. Typically, when illness (called "flu&qu ot;) from an avian flu virus does occur, it is the result of an avian flu virus strain adapted to one species spreading to another species (usually from one bird species to another bird species). So far as we know the most common result of this is an illness so minor as to be not worth noticing (and thus little studied). But with the domestication of chickens and turkeys, we have created species subtypes (domesticated poultry) that can catch an avian flu virus adapted to waterfowl and have it rapidly mutate into a form that kills in days over 90% of an entire flock and spread to other flocks and kill 90% of them and can only be stopped by killing every domestic bird in the area. Until H5N1, this was basically the whole story of avian flu so far as anyone knew or cared (outside of the poultry industry). Now with H5N1, we have a whole new ballgame with H5N1 inventing new rules as it goes with behaviors never noticed before, and possibly never having occurred before. This is evolution right before our eyes. Even the Spanish flu virus did not behave like this. What is worth mentioning about illness from avian flu viruses is covered in H5N1 flu, Flu, and the subtype articles (H5N1, HxNy) linked below.
As of 2006, avian flu is being commonly used to refer to infection from a particular subtype of Influenza A virus, H5N1, which can cause severe illness in humans who are infected.
Currently, this strain is transmitted by contact with infected birds, and has been transmitted from one person to another only in a few cases.
H5N1 flu is therefore not pandemic now and is not currently capable of causing a pandemic. Only if H5N1 mutates into a form that can be readily transmitted from one person to another could it cause a pandemic.
You may also go to the United Nation's World Health Organization' ;s Avian Flu Facts Sheet for 2006 at the website of the UN WHO World Health Organization
- 活力先生Lv 71 decade ago
- 1 decade ago