Bird flu or avian influenza.
Bird flu, otherwise called avian influenza, is a viral infectious disease occurring in wild and domestic birds and it is caused by type A  strains of the influenza virus. Fifteen different subtypes of strains contained in this category seem to have infectious results in birds. The vulnerability of each kind of birds and the harmfulness of each subtype of strains varies. For instance, pigeons seem to be quite resistant to bird flu and the most commonly pathogenic subtypes are the H5 and H7 ones. It has been acknowledged that the longer the time the avian influenza is circulated in wild bird populations, the more likely for the virus to mutate to highly pathogenic forms. The resent outbreak of bird flu is caused by the H5N1 strain which is extremely contagious and highly lethal among birds.
The core of the occurrence of bird flu seems to be in migratory waterfowl birds, especially ducks. The present bird flu is described as highly pathogenic avian influenza and it has been spreading in areas located along the flight routes of the migratory birds. The virus of bird flu is transmitted with the saliva, mucus and mainly with feces of the infected subjects. As soon as the feces get dry and turn to powder or dust they can be inhaled or eaten by free-range domestic poultry flocks, such as chickens or turkeys. Birds that manage to survive a H5N1 avian influenza remain contagious, since they keep on shedding the virus for at least ten days after the symptoms retreat. The virus of bird flu can survive indefinitely in temperatures below zero degrees centigrade, for long periods in low temperatures and for at least four days in mild or hot environment.
Bird flu in humans.
After reaching domestic birds, the virus of bird flu comes in very close proximity to humans and can be transmitted to them through the respiratory track,  resulting in sever health complications and potential death. In rural areas the H5N1 virus can easily spread with the infectious fecal dust or powder which can be transferred by the wind or contaminated vehicles, equipment, clothes and shoes.
At the present time, there is no evidence that avian influenza can be transmitted among humans like the common flu. However, specialists believe that this will happen soon or later, since the genetic material of the bird flu virus is very unstable and alters easily. The crucial point will be, when the common flu virus and the H5N1 coexist in a human's body. In such a case, the two strains will exchange genetic material; they will mutate during replication and produce a new kind of flu virus. This new strain will be very contagious among humans and extremely pathogenic as the common flu and the avian influenza, its ancestors, are. The same process can happen in pigs, since these animals can be infected by both types of flu viruses.
Symptoms and complications of bird flu.
In poultry, a mild or sever clinical type of avian influenza may occur. The first one is characterized by moderate weakness, ruffled feathers, mild respiratory difficulties and decreased egg production. The second type involves sudden and severe illness which is associated with mortality that may reach the 100% of the cases.
In humans, bird flu can cause cough, sore throat, muscle aches, fever and severe respiratory conditions, such as pneumonia or acute severe respiratory distress. In many cases, bird flu may be fatal.
Antiviral medications and bird flu.
Although great efforts are underway, at the moment, there is no vaccine against avian influenza, because the virus is very unstable genetically and mutates easily. However, certain antiviral drugs can be effective. Although the H5N1 seems to be resistant to rimantadine (Flumadine), it seems to be vulnerable to zanamivir (Relenza), amantadine (Symmetrel) and especially to oseltamivir (Tamiflu). Studies have shown that a combination of Symmetrel and Tamiflu can give an effective treatment scheme for bird flu. Tamiflu may be prescribed for either preventive or therapeutically reasons. In a case of bird flu treatment, the drugs must be used within the first two days from the onset of symptoms. Click the relevant link below, if you want to find more information about bird flu treatment. Also, you will be guided how to find antiviral drugs online.
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