Tuesday, December 28, 2010

Winter Colds and Flu

Viruses have been described as ‘organisms at the edge of life’. They are true intracellular parasites, destroying their host cells as they replicate. Viruses lack a cellular structure (which is regarded as the basic unit of life), although they do have genes, enveloped by a simple envelope in some cases. They do not self-metabolize and they need a host cell to replicate and synthesize new products. Viruses only resemble other living organisms in that they possess genes and can evolve in infected cells by natural selection, reproducing by creating multiple copies of themselves through self-assembly. Without a living host cell, very specific to each virus, there would be no replication.
Over 200 different viruses can cause the 'common cold' and most of the causative organisms are found within the Rhinovirus family. This collection of genetic material that causes our most common worldwide infection is so neatly presented that the cold virus can be found on every corner of our planet and remain active without a host for hundreds of years. They are so small that around 500 million viral particles can be squeezed onto the head of a pin. Head cold symptoms remain typically centered around the nose - symptoms include nasal stuffiness, sneezing and pharyngeal irritation (usually without redness). Flu viruses may also cause ‘cold-like symptoms’ where approximately 15% of ‘head colds’ are actually caused by flu viruses.
What happens to you when you contract a viral infection is largely determined by the overall state of your health and especially how effectively your immune system responds to the attack. Your innate immune system is your first line of defense and effectively wins the battle against most viral organisms entering your body.
Conventionally, the flu vaccine is recommended as flu prevention, but what must be realized is that getting the flu vaccine does not guarantee that you will not contract the virus. If the strain of virus that you contract is not included in the vaccine that you receive, you will not have protection against those strains. Antibiotics are only effective in controlling some of the secondary complications; they have no effect on killing the flu virus itself. We all have a developing immune system that has highly specialized white blood cells called lymphocytes that have the ability to develop a 'memory' of every viral particle it encounters. This memory of the viruses prevents us from being ill all the time, because the reality is that cold and flu viruses are always around, and we are always exposed to them.
Flu viruses infect birds, pigs, and humans; but do not necessarily cause illness in all of its 'hosts'. While some types of flu viruses don't harm birds, they can overwhelm and kill humans. These specific hosts allow viruses to remain in our environment and survive during the unfavorable warmer months of the year when our resistance on mucosal membrane surfaces does not allow for frequent infections. The dry and cold winter air promotes viral transmission and this is further compounded by the use of heaters indoors which further dries the air out and puts us at risk for picking up infections via the respiratory passages, nasal membranes and tear ducts. The flu virus, one of the fastest mutators amongst viruses, can rapidly infiltrate the nasal passages, throat, bronchial tubes and lungs. Common symptoms of flu include:
  • Fever and chills
  • Loss of appetite
  • General aches and pains
  • Aching muscles
  • Headaches
  • Weakness
The secondary complications to flu result in lingering illness that may cause deeper damage within the body. Susceptible people may get severely ill with these secondary complications. If you are prone to secondary complications you may need to take more care this flu season. Pneumonia (which may be viral or bacterial) is one of the most serious consequences of flu. The sixth leading cause of death in the U.S.A. yearly is influenza and pneumonia combined. Other secondary illnesses include:
  • Sinusitis
  • Laryngitis
  • Bronchitis
  • Ear infections
Supporting immune function during a viral infection allows a more effective and targeted response with subsequent exposures. Our immune systems need to respond effectively throughout our lives. Constant infections and slow healing times with the continuous need for antibiotics is a clear sign that your immune response is not functioning properly. This is seen commonly in children where an over-dependence on antibiotics from a young age can result in antibiotic resistant bacteria and a diminished immune response.

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