Influenza Pandemic Term Paper
- Length: 12 pages
- Subject: Disease
- Type: Term Paper
- Paper: #3952599
Excerpt from Term Paper :
Classification of the influenza virus
Definition of pandemic and causes and reasons for its spread
How well is USA prepared for the onset of the influenza virus?
The morbidity and mortality rates of the influenza virus
Details about WHO and CDC and their methods of tackling the disease
What is Influenza and how does it spread:
Influenza is defined as a severe infection of the respiratory tract and is shown in the inflammation of the nasal mucosa and the pharynx and the eyes and the patient suffers from a headache and more often severe myalgia. He also suffers from chills, prostration, muscle aches, a sore throat and also, a dry cough. Influenza is also known as the flu and is described as an infectious disease caused by the inhalation of an infectious virus. It may become a life threatening disease in infants, the elderly, and some people whose immunity systems are compromised. It is highly contagious and, if unchecked, may cause an epidemic.
When the influenza virus becomes deposited in the respiratory tract of a person, the various signs and symptoms appear almost immediately. The onset of the symptoms is almost like being hit by a truck; this is how a patient may experience the virus. Some patients can even accurately pinpoint the time of the onset of the fever or chills or the cold. Some patients may face photophobia other ocular problems and though these are not very common symptoms, they may occur in some rare cases. In some children, there may be stomachache and vomiting and also a feeling of general malaise. In infants these may become difficult to diagnose and the treating physicians are warned against treating them as symptoms of an ordinary common cold, whose symptoms are very similar to those of influenza.
Influenza can cause morbidity as well as mortality if it is not treated on time. It is a fact that almost 10,000 deaths occur for every epidemic of influenza. The Center for the Prevention and Control of disease states that more than 20,000 people died of the influenza virus during each outbreak in the years 1972 to 1973, and in the years 1994 to 1995. There were about 11 flu epidemics in different parts of the U.S.A. during these years, and more than 40,000 per epidemic have been reported to die. The figure for the mortality rates for the years 1994 to 1995 due to the influenza virus is a high 8.7% in 122 cities of the U.S.A. All age groups are prone to this infection since it is extremely contagious and it makes its presence felt within hours after inhalation and incubation. However, the sad and very true fact is that very few elderly are able to survive the onset of this disease, and this is mainly due to its cardio-pulmonary and upper respiratory tract effects, and not because of the disease itself. The complications of the disease are generally rhinitis, sinusitis, bronchitis, and otitis media.
While it is true that the elderly are more prone to deaths from the influenza virus, the very young are also prone to severe infection that may eventually lead to death. The fact is that for every death occurring due to the virus, another 10 to 12 persons are taken to hospitals for the treatment of this dreaded disease. During the epidemics of the 1960's and the 1990's, more than 20,000 to 30,000 people were hospitalized for treatment. The influenza virus peaks its attacks during the months of November through April. While a 'widespread outbreak', according to the center for the Prevention of Disease and Control, is when the virus affects about 50% of the entire county population of the various states of the U.S.A., a 'regional outbreak' is when the virus affects less than half of the counties of any particular state of the U.S.A.
When an affected person sneezes or coughs or even talks, the virus is propelled into the air and it enters another person's system. This is how the influenza virus spreads. This is why persons taking part in any sort of indoor gathering, children at a school, and persons in a nursing school are all prone to the virus, and almost 20% to 50% of the entire community is affected immediately. School age children are primarily responsible for bringing the virus to their own homes and therefore affecting their parents who thereafter affect their workplace, from where the virus spreads easily to other places, like for example, the transportation network that the parent uses for traveling to his work and back, the places he visits during the course of his work, and so on.
Classification of the Influenza Virus:
The Influenza Virus is generally classified into three groups according to the differing nuclear proteins that they are made up of: Type A, Type B, and Type C. The first type, A, is capable of causing severe illness and the very fact that this deadly virus is prone to change its composition makes it extremely difficult to keep track of and this in turn makes it deadly and this type A virus is usually responsible for the outbreaks of 'pandemics'. The two key surface proteins of the type- A influenza virus are the hemagglutinin and the neuraminidase, that are also known as HA and NA respectively. These two 'subtypes' as they are known, demonstrate a different sequencing of their amino acids within each protein, and about 15 different subtypes of HA and about 9 different subtypes of NA have been identified so far.
Of these, only 5 HA subtype and 2 NA subtypes have been known to have infected human beings over the years. The other subtypes, though they do not affect humans, are known to survive in the environment in the bodies of hosts for long periods of time and some may infect horses, birds, and swine. The problem lies in identifying these various subtypes and creating antibodies for all of them. It is a sad fact that, every time an antibody is manufactured and named for the subtype it was made to fight against, another subtype is discovered, and an antibody has to be created for the new subtype too. Therefore it is important that these subtypes are identified immediately and antibodies manufactured as soon as possible. The protection of antibodies cannot be underestimated in any manner, and the better an antibody, the better the chances of recovery from this disease are.
However, the great problem faced by health institutions is that these viruses are capable of slow change, that is, they are capable of altering their constitution by a process of mutation and changes that occur in their amino acids that make up the hemagluttinin and the neuraminidase surface proteins. Therefore, a virus of type A or of type B, after it has established itself in the host, can adapt and survive. Thus, an influenza virus that undergoes an antigenic shift may become capable of changing its constitution and may live for years, unhindered. This in turn may make it difficult for the person treating the infection to identify it as belonging to a particular type, and this in turn will cause the patient untold misery, because unless proper diagnosis and treatment of the virus with appropriate antibodies are accomplished, the patient will know no relief. When the virus is undiagnosed and allowed to grow unchecked, there will be an epidemic. The cycle goes on uninterrupted: when an antibody is discovered to fight a particular strain of the virus, the virus mutates, and the antibody then becomes useless. By the time this is discovered and a new antibody is manufactured, the virus has learnt to survive by repeatedly mutating in different ways, and the specific antibody will not work.
Pandemic' and the causes for its spread:
The end result of this endless antigenic shifting as well as of antigenic drifting of the influenza virus is the epidemic and eventually the pandemic. The dictionary definition of 'pandemic' is an epidemic that is widespread, geographically, occurring throughout a particular region or even all over the world. A pandemic, in other words, is larger than an epidemic. (Hyperdictionary) Therefore, the implications of a pandemic are definitely larger than those of an epidemic and it is infinitely more dangerous and risky to be in the throes of a pandemic. A solution will have to be found to combat the influenza virus before it can become uncontrollable. In order to do this, one has to learn how the virus multiplies and escapes from every antibody invented by man. Suppose that a new virus-call it type 'A HxNx' was brought into a group of people for whom there was no antibody against this particular virus. What would happen is that the virus would spread uncontrolled throughout the world, thus causing a pandemic.
However, after a period of exposure to the new virus, antibodies would be introduced to fight it, and this would result in the formation of new…