The Flu - What is it?

Flu is the popular non-medical term given to the influenza disease, also known as grippe.  The flu is an acute, infectious and extremely contagious viral disease that comes on suddenly.  The onset may be so sudden, a matter of few minutes, that it is a almost unbelievable that a person could feel so bad so quickly.  It can afflict humans, birds and mammals alike. 

Types of Flu

This disease is caused by any one of three strains (A, B, C) of influenza viruses.  Orthomyxoviridae family is the name given to this family of influenza viruses that can cause distinct types of flu with weaker or stronger characteristics.

In addition, while these three strains of influenza viruses have the ability to mutate into newer, more powerful or cunning forms, type A influenza mutates constantly, producing new strains of the virus every few years.  In other words, you can never be indefinitetly immune to flu.  This means that the antibodies that you may have developed against the flu virus one year, are unlikely to protect you against a new strain of the flu virus another year. 

The type A strain is the most damaging to humans, and the Spanish flu, Asian flu, Hong Kong flu, and the H5N1 avian flu are all type A strains.  Currently, the world is facing a particularly deadly form of influenza known as the H5N1, or bird flu strain.

While major epidemics occurring from time to time are caused by type A mutations, types B and C are not so common, generally resulting in milder cases and local outbreaks.

Flu Virus Symptoms - How does influenza virus attack the body?

The flu symptoms are fairly well known.  Influenza attacks suddenly with chills, high fever generally between 101° F and 102°F and uncommonly as high as 106°F, muscular aches, headache, prostration, weakness, loss of appetite, general aches and pains, sore throat, nasal congestion, sneezing, irritated eyes, extreme coldness (combined with shivers), severe coughing, and a general state of fatigue and nausea.  Symptoms are similar to those of the common cold, creating some confusion that we clarify on the next article.  On particular cases of flu, the symptoms may include vomiting, headaches, loss of smell, sore joints, heavy sneezing and so forth.
There may be abdominal pain and diarrhea.

While symptoms for most flu types are roughly similar, each new virus may bring additional effects to the body. 

A main danger from this disease is that germs that may be hiding in the nose and throat will attack the weakened body causing ear infections, sinusitis, or other complications.

How long does the flu last

In general, the acute symptoms last for only a few days, followed by a gradual recovery of normal strength.

Incubation period:  1 to 4 days.  An because influenza is excedingly infectious, the disease spreads quite rapidly.  The infection enters thru the nose and moth and is transmitted to some extent by sneezing and coughing.
Danger of contagiousness: the disease is probably not transmitted by the infected person for more than a week after the onset.  However, persons with an illness so light that are not manifesting its true nature, play an important part in spreading the disease. 

Flu Seasons

As with most viral diseases, flu is favored by some external weather and season factors. The peak in the Northern Hemisphere is during January or February however, it needs to be taken into account that the winter season occurs at different times throughout the world.  In relation to this fact, the World Health Organization (WHO), with the help of the National Influenza Centers (NIC) produce two anti-flu vaccines per year, in order to cope with both peaks.

Science is still unsure about what causes the seasonal influenza, but it is suspected that the cause is due to the fact that people are in close quarters more often during the winter time. Also, colder temperatures can provide a more stable environment for the virus to live, for example, it may stick around longer than usual when it is spread through things such as doorknobs.

Some strains of the influenza virus tend to find it more suitable to spread during the change from winter to spring.   At the first sign of relative spring heat, clothing changes radically to lighter accessories and this radical change makes it easier for the virus to spread. In some areas that are close to the tropics, the flu peak is considered to be all through the year, so these are the most likely to be hit by a pandemic.
During an epidemic it is good advice to keep out of crowds.