“A predictable Pandemic” says , New Scientist, “People are nervous about swine flu, …regular flu kills 36,000 / year, in US”. CNN on line. .  “The number of confirmed swine flu cases has jumped to 507 in New Zealand.….three people who have died in the past week had the virus” TVNZ . It all originated in Mexico with over 150 deaths in June 2009. But then why this discrepancy in the North and South? In Australia and NZ its fast spreading while in US it has fizzled out.

Commonest of all viral diseases is the Common cold. The name implies that the cause of the disease as the exposure to bad weather. But it has been proven that the Rhinoviruses and Corona viruses are the main culprits for the disease. ( Malik Peiris of the University of Hong Kong is credited for the discovery of one corona virus just prior to the Avian flu epidemic) )The symptoms, sore throat, runny nose, and sneezing are well known.  There is no known cure for this and there’s no need for it either. The immune system of a normal healthy patient can tackle the disease in 7 to 8 days and bring about a permanent immunity. People get the disease more than once due to the vast number of viral types present and the rapidity with which they undergo changes.

The virus H1N1 is not an alien; it visited us in 1918 as the Spanish flu and claimed around 100 million lives around the globe. Most of the deaths were due to an overreaction of the immune system known as cytokine storm. This explains the healthy young adults to have been at the receiving end. Some died of secondary infections like pneumonia and the virus also directly killed an appreciable number. It may be worthy to note that after the high wave died out two other waves followed.

The present 2009 flu virus that originated in Mexico seems to be a unique one.  The pig was the original host of this virus. Some pig farmers contacted the disease once in a way but it was not passed on to others.  The pigs were also susceptible to Bird flu too. It was possible for them to get two form of flu at the same time.  So the pig became the mixing bowl of the viral genes. Human being had no immunity for this new strain.

Pathogens gain entry through the nasal cavity and gets trapped in the shelves called turbinate. In a few minutes these are transferred to the adenoids at the back of the throat. The viruses attach themselves to the cells there and transfer their genes and compel the molecular machinery of the host cell to replicate the viral genes. These soon gain control immobilizing the host genes and produce a cluster of young viruses. They burst the host cell and emerge ready to enter the other healthy cells in the tissue.

 By this time immune system of the host would have recognized the invader. Defense headquarters, bone marrow, liver, thymus, tonsils, lymph nodes, and the spleen, will dispatch the troops and ammunition along the blood and lymph vessels. T-cells, (White blood cells fighting viral infections). B- cells (Cells that make specific proteins called antibodies) along with natural killer cells (NK cells) and phagocytes that swallow viral infected cells not only counteract the attack, but maintain surveillance sometimes for the rest of the individual’s life.

Disease	Virus	Symptoms	Treatment .	Prevention
1. Common    cold	Rhino virus Corona virus	Sore throat, runny nose, sneeze,	Rest . Excess water.	Balanced diet Exercise
2. Seasonal Influenza	Rhino virus Corona virus (Type A or B, H1N1, H2N1,  H3N2.)	Sore throat, runny nose, sneeze, fever, cough.	Bed rest , Excess water	Seasonal vaccine.   Washing hands after work.   Do not touch your nose, or put your hand in the mouth or scratch the eyes.   Avoid crowds.
3. Bird flu	1997 &2003-  H5N1	Fever, cough, sore throat, and muscle aches to eye and lung infections,.	Amantadine and rimantadine,
4. Swine flu	A/H1N1	Fever, cough, headache, joint and muscle pain, sore throat, fatigue, chills, runny nose diarrhoea. And vomiting.	Tamiflu and Relenza.