Sunday, December 16, 2012

Highly Pathogenic H5N1: Deadly to Birds and to Humans

Influenza A virus or more known to us as H5N1 is an avian (bird) flu, an influenza A subtype that has caused outbreaks in domestic poultry in parts of Asia and the Middle East.  This is deadly to them and is considered “highly pathogenic” meaning highly disease causing.  Although the virus does not usually infect people but infectious that these viruses occurred in humans.  Most of these cases have resulted from people having direct or close contact with H5N1-infected poultry or H5N1-contaminated surfaces.

There are three types of viruses, A, B, and C, that can cause flu to human.  The type A is characterized not only to human but to other mammals and birds too.  The virus transmitted by air.  The type A virus is composed of two obligatory protein components. One is called hemagglutinin and is lettered H, and the other—neuraminidase (N).  And there are 13 variants of hemagglutinin and 9 of neuraminidase, which then can characterized what type of virus it is.  Making H5N1 is just out of the many possible variants of the virus structure.

Many parts of the world has been infected by the virus such as Asia, parts of Europe, the Near East Africa, birds as well as half of the humans infected did not survive.  The outbreaks infected poultry and wild birds, and humans who have direct contact with the infected animal.  In most cases, healthy children and young adult and have resulted from direct contact with H5N1-infected poultry or contaminated surfaces were infected.

The H5N1 virus does not infect humans easily and in general it remains very rare disease in people.  If the person is infected it is not that easy to spread it to another human.  However, there has been some human-to-human spread of the virus although it is limited.

But scientists are anxious that H5N1 virus one day could infect humans then spread easily from person-to-person because viruses such as influenza have the ability to change.

Although at the moment that the virus do not commonly infect humans, there is little or no protection against them and if the virus will change and could begin to spread from human-to-human there will likely result a very high deaths.

To know whether infected by the virus, people may show as follows:


Fever and cough
Acute respiratory distress
Shortness of breath/difficulty breathing
Abdominal pain
Muscle aches
Breathing problems (severe cases)
Pneumonia (severe cases)

Respiratory failure
Altered mental state
Failure of multiple organs (e.g. kidney failure)

If someone with H5N1 experienced diarrhea followed rapidly by a coma without developing respiratory or flu-like symptoms.  Studies showed of the levels of cytokines in humans infected by the H5N1 flu virus.  Of main concern is an elevated level of tumor necrosis factor-alpha, a protein that is associated with tissue destruction at sites of infection and increased production of other cytokines.  A flu virus-induced increase in the level of cytokines is also associated with flu symptoms including fever, chills, vomiting and headache.  Tissue damage associated with pathogenic flu virus infection can ultimately result in death.

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