|Fig 1:Structure of the virus.|
Influenza according to Patient.co.uk is defined two ways. Firstly ''Uncomplicated influenza is defined as influenza presenting with fever, coryza, generalised symptoms (headache, malaise, myalgia, arthralgia) and sometimes gastrointestinal symptoms, but without any features of complicated influenza.'' And Secondly as; ''Complicated influenza is defined as influenza requiring hospital admission and/or with symptoms and signs of lower respiratory tract infection (hypoxaemia, dyspnoea, lung infiltrate), central nervous system involvement and/or a significant exacerbation of an underlying medical condition.'' (Patient.co.uk, Unknown)
This virus is separated into three separate classifications A, B and C. These three classes have their own stages in which the Virus mutates and makes up three of the five genera (a biological term for a living and fossil organisms,) of the Orthomyxoviridae. (A family of RNA [ribonucleic acid] virus's.)
This is stand of genus that contains the Influenza A virus. Wild birds from the arctic are the most common carrier hosts of Influenza A. It happens on occasion that the virus is transmitted to another species which then causes a devastating mutation of the virus and it spreads rapidly to other hosts, specifically domestic poultry which could then lead to an rising pandemic that affects us humans. The Type A virus is the most severely harmful of the three types and can cause the most severe of diseases.
The Type A virus is subdivided into different variations which are based on the antibody that respond to the virus. These are some of the subcategories that caused epidemics and major disease over history:
- H1N1, which caused Spanish Flu in 1918, and Swine Flu in 2009
- H2N2, which caused Asian Flu in 1957
- H3N2, which caused Hong Kong Flu in 1968
- H5N1, which caused Bird Flu in 2004
- H7N7, which has unusual zoonotic potential
- H1N2, endemic in humans, pigs and birds
The Influenza B virus is almost exclusively infects humans and is less common than Influenza A.
The only other animals known to be susceptible to influenza B infection are the seal and the ferret. This type of influenza develops and mutates at a rate 2 to 3 times slower than type A and is less genetically different. Immunity to influenza B is usually acquired at an early age. However, influenza B mutates enough that lasting immunity is not possible. This reduced rate of change, combined with its limited host range, ensures that pandemics of influenza B do not happen.
The final class of the virus influenza C virus, which infects humans, dogs and pigs, sometimes causing both severe illness and local epidemics. However, influenza C is less common than the other types and usually only causes mild disease in children.
|Fig 2: Process of Infection|
The virus can be transferred to another being in a number of ways, but mainly through coughing or sneezing over another person, as well as through contact with the hands or eyes of the infected. The process in which the virus enters the body is simple, but the way it affects the body is complex and can alter from person to person. Usual symptoms of the virus conclude a fever, cold/cough, nasal discharge, headache, uncomfortable feelings, tiredness, muscle ache and other symptoms conclude development of swine flu and essentially, untreated cases of severe virus infection can lead to death. It can be treated with antibiotics or paracetamol at strong levels I assume.
Image List:Fig 1. Structure of the Virus Google Search/Wikipedia, unknown. http://upload.wikimedia.org/wikipedia/commons/3/3b/3D_Influenza_virus.png. (Accessed on the 26/02/15)
Fig 2: Process of infection. How Stuff Works. Unknown. http://s.hswstatic.com/gif/flu-respiratory.gif. (Accessed on the 26/02/15)
Bibliography:Patient.co.uk. Unknown. http://www.patient.co.uk/doctor/influenza. (Accessed on the 26/02/15)