Virus HPAI A (H5N1) was first known to kill a flock of chickens in Scotland in 1959, but the virus that emerged at that time very different from the H5N1 virus at this time. Dominant species of the H5N1 virus that emerged in 2004 evolved from a virus that emerged in 2002 that created the gene type Z.
The H5N1 virus is divided into 2 types of derivatives, the first derivative is a virus that infects humans and birds in Vietnam, Thailand, Cambodia and birds that exist in Laos and Malaysia. Type the first derivative does not spread to other areas.
Meanwhile, a derivative of type 2 identified from birds in China, Indonesia, Japan, and North Korea which later spread to the Middle East, Europe and Africa. Virus type 2 of this derivative into is the virus that causes the infection to humans that occur in the period 2005-2006 in various countries. Genetic analysis has been done to prove that there are 6 types of subclasses of the derivative type 2, the 3 of them spread and infect humans in the following countries:
Subclasses 1: Indonesia
Subclass 2: Europe, Middle East and Africa
Subclass 3: China
H5N1 is actually a type of virus that attacks the galactose receptors that exist on the nose to the lungs in birds that are not found in humans, and attacks only occur around the alveoli of the areas in the lungs where oxygen is transmitted through blood. Therefore, this virus is not easily spread through the air when coughing or sneezing like a common cold virus.
Since it was first discovered in 1997, researchers found that the H5N1 virus continues to evolve with changes in antigenic substance and structure of the internal genes that then can infect several different species.
The virus was first discovered in Hong Kong in 1997 and 2001 is not easily transmitted from one bird to another and do not cause lethal disease in some animals. But in 2002, a new type of H5N1 virus emerged, known as the H5N1 virus gene type Z which became the dominant type of gene, which causes acute disease in bird populations in Hong Kong, including neurological dysfunction and death in ducks and other fowl.
The virus with this gene type that became epidemic in Southeast Asia that caused the death of millions of chickens and from 2 sub-class created by the ever-changing virus mutation has caused hundreds of human victims who died. Mutations that occur from this strain of pathogenic virus that can increase exacerbate attacks and viruses to different species of fear it will correctly transmit the virus from humans to other humans. Mutation occurs in the body of the bird that keeps the virus in a long time in her body before eventually died of infection.
Mutations that occur in H5N1 viruses is characteristic of type A influenza virus, where the virus is able to combine the two types of influenza viruses of different types which are in 1 type receptor at the same time.
The ability of viruses to mutate to produce the type that can infect various types of species is due to the variation in the hemagglutinin gene. Genetic mutations in the haemagglutinin gene causes an amino acid shift in akhrinya can change in the hemagglutinin protein ability to bind to receptors on the cell surface.
These mutations can alter the H5N1 bird flu virus that was unable to infect humans become easily transmitted from birds to humans. Therefore, researchers are now actively trying to understand nature-very jealous of this virus and tried to do genetic engineering by inserting two amino acids H1N1 Spanish flu virus into the haemagglutinin of H5N1 that will not be a pandemic of H5N1 viruses that harm humans as it did in an outbreak in 1918.
The study yielded encouraging results in which the object of research can stay healthy even if placed in a room with objects that sick.
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