Friday, September 3, 2010

Avian Influenza Causes

The cause of avian influenza is influenza A virus subtype H5N1. Influenza virus included in the Family Orthomyxoviridae consisting of 3 types of pathogens for human influenza virus that is type A, B, C. Influenza virus A spiral-shaped symmetrical and has a casing that encloses the genetic material in the form of single chain RNA negative polarity. This virus has 2 types of protrusion of the haemagglutinin (H) and neuraminidase (N). Strains of type A were coded according to antigenic properties of the haemagglutinin (H) and neuraminidase (N) as an example of H1N1, H2N2, H3N2 and H5N1. And there are 16 H subtypes (H1-H16) and 9 N subtypes (N1-N9).

In influenza A virus can occur major changes in antigenic composition, called antigenic shift. Or small changes in antigenic composition, called antigenic drift. Peubahan these changes that lead to epidemics and even pandemics.

The wave of the epidemic because of influenza A viruses periodically take place every 2-3 years, while the period of interepidemi for influenza B is longer ie 3-6 years. Every 10-40 years, when the influenza A virus subtype appears new, there will be a pandemic like the 1918 (H1N1), 1957 (H2N2) and 1968 (H3N2). In the year 1997 has emerged a new subtype of H5N1, although until now has not resulted in a pandemic.

In humans there is only influenza A viruses of subtypes H1N1, H2N2, H3N3, H5N1, H9N2, H1N2 and H7N7. While the animal is a subtype H1 to H5 and N1 to N9.

Of all these subtypes, only influenza A virus subtypes H5 and H7 that have been known to cause a dangerous disease. However, not all influenza virus subtypes H5 and H7 dangerous, and also not all cause disease in poultry.

It is important to know the properties of avian influenza virus (H5N1), because then to find out how Vitus H5N1 transmitted and how to prevent transmission.

The properties of avian influenza virus (H5N1) is:
- Easily change the shape and mutate
- Survival in water for 4 days at 22 "C and more than 30 days at 0" C.
- Survive live longer in the body of sick birds.
- Dead on heating 80 "C for 1 minute or with a temperature of 60: C for 30 minutes and at a temperature of 56" C for 3 hours.
- Off with detergent, disinfectant (formalin), the liquid containing iodine (betadine) and potassium sodium hypochlorite (bleach clothes).

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