Among the primary influenza causes is infection with the influenza virus. While the influenza virus can be contracted from various places and in many ways depending on the kind of flu virus, the main reason for influenza is the virus entering into the system. There are three main types of influenza virus – A, B and C. While type A and B are considered to cause acute symptoms that can cause an epidemic, type C virus generally causes mild symptoms that can be managed relatively easily. Type C virus also almost never results in an epidemic. The type A virus is also further subdivided into various subtypes based on the 2 proteins that are found on the layer. There are 16 H subtypes and 9 N types that are known. Bird flu causes and swine flu causes are also limited to contracting the specific virus subtype H5N1 and H1N1 that cause the medical condition.
Even though the influenza virus has been around for a long time, scientists and researchers have been unable to find a foolproof vaccine to prevent all kinds of influenza medical problems. This is mainly because of the fact that the influenza virus changes as it undergoes mutations or changes in the RNA structure. So as soon as the human body acquires the natural immunity towards the flu strain or even before science can create a vaccine to fight the virus, it changes into a new strain that become predominant making it impossible to fight the flu virus completely.
Human flu virus is transmitted when droplets of water fall from the infected person to a healthy human. This can occur when an infected person sneezes or coughs. The flu virus can also spread if the infected person has had direct contact with an object and a health person touches the same object minutes afterwards. During an epidemic therefore, one of the swine flu causes has been direct contact with public objects such as door handles and public telephone booths.
The bird flu on the other hand is not a very common human virus. There have been cases of bird flu in humans but one of the main bird flu causes has been consumption of infected poultry or eggs since this virus is fairly common among fowl and chicken. Transmission of this virus from one person to another is rare and unheard of.
The influenza virus needs a host to survive and therefore it is quick to pick on someone as soon as it is ejected from one human system. The virus attaches itself to the host and takes over the cell, immediately using the host RNA to replicate and reproduce itself into millions of viruses in no time. Since the influenza causes are limited to contracting the virus, prevention is the key to ensuring that you do not get the disease.