| Bird flu is a disease caused by type "A" influenza | | | | influenza viruses (H1N1, H1N2, and H3N2). There is the |
| viruses. | | | | possibility that these subtypes to have came from |
| Wild birds are a natural reservoir of type A of flu | | | | birds originally and scientists worry about the |
| virus, but they are not affected by it. They can | | | | possibility that the bird flu viruses to mutate and |
| infect domestic birds such as chicken or turkey, | | | | transmit from human to human. |
| which get ill and die. | | | | Some symptoms of bird flu infection on humans are: |
| Birds get infected if they get in contact with | | | | fever, lethargy, sore throat, breathing problems, |
| secretions or excretions of the affected birds, with | | | | conjunctivitis, muscle aches and cough. |
| contaminated water or food and even with | | | | Studies suggest that antiviral drugs used against |
| contaminated surfaces (dirt and cages). | | | | human influenza might be useful in treating bird flu |
| The avian influenza viruses can cause a mild form of | | | | infection in humans too, but this thing must be |
| the disease that does not kill the infected birds, and | | | | studied more. |
| it only reduces the egg production, and a highly | | | | The H5N1 virus is one of the most lethal subtypes of |
| virulent form that can lead to death within 48 hours | | | | the influenza "A" virus. In the last few years, in Asia, |
| by multiple internal organ lesions. | | | | H5N1 caused millions of deaths among domestic birds |
| Type A of influenza virus has many different | | | | and hundreds among humans. People got infected |
| subtypes due to changes in some proteins situated | | | | because they got in close contact with the infected |
| on the surface of the A virus. These changeable | | | | poultry and the contaminated surfaces, but otherwise |
| proteins are Hemagglutinin (HA) and Neuraminidase | | | | H5N1 remains a rare disease in people and does not |
| (NA). There exist 16 known HA subtypes and 9 NA | | | | spread from human to human. |
| subtypes of "A" virus, but there are possible many | | | | There was one case in Indonesia where a family |
| combinations between HA and NA proteins, leading to | | | | member is suspected to have transmitted the illness |
| new subtypes. All these subtypes can now be found | | | | to the other members, but this fact has not been |
| in birds. | | | | sustained scientifically. |
| Until 1997 nobody knew that the virus can affect | | | | Scientists are concerned about a possible mutation of |
| humans, but it has happened to those who have | | | | the virus, leading to a global pandemic, similar to the |
| been in close contact with infected poultry. Until now, | | | | Spanish flu pandemic of 1918-1919 when 40-50 million |
| no cases of human to human transmission of the | | | | people died. |
| infection were registered. | | | | Doctors have discovered that H5N1 virus is resistant |
| Human influenza viruses generally refer to those | | | | amantadine and rimantadine, two antiviral drugs used |
| subtypes that can infect only humans. There are | | | | for treating human influenza. There remain |
| known to exist three "A" subtypes of human | | | | oseltamavir and zanamavir to be tested. |