Swine flu vs Ordinary flu
What we normally refer as flu is a regular seasonal influenza that are endemic to the human population. This seasonal flu spread in human by H1N1 virus. This influenza virus is transferable from human to human.
There are three major types of Flu or human influenza; Influenza Type A, B, or C. Most seasonal flu would fit into one of this category.
What is 2009 H1N1 influenza (swine flu)?
Human swine flu is not the same as seasonal influenza spread by H1N1 virus. Swine flu is an influenza that is spread by 2009 H1N1 virus. This virus causes a mild illness in most people, however the virus can cause death due to viral pneumonia and lung failure in a small proportion of people.
This new 2009 H1N1 virus was first detected in human in Mexico and United States in April 2009 and was spreading from person-to-person in much the same way the regular seasonal influenza viruses spread, it was named by WHO (World Health Organization) as 2009H1N1. It is also known as A/H1N1 2009 or Pandemic H1N1 2009, because this influenza is type A and was announced by WHO as pandemic.
A pandemic is the worldwide spread of a new disease. An influenza pandemic occurs when a new influenza virus emerges and spreads around the world, and most people do not have immunity. Viruses that have caused past pandemics typically originated from animal influenza viruses.
WHO informed that this is an influenza virus that had never been identified as a cause of infections in people before the current H1N1 Pandemic. Genetic analyses of this virus have shown that it originated from animal influenza viruses and is unrelated to the human seasonal H1N1 viruses that have been in general circulation among people since 1977.
2009 H1N1 virus was originally referred to as “swine flu” because initial laboratory testing showed that many of the genes in the virus were very similar to influenza viruses that normally occur in pigs (swine) in North America.
But further study has shown that the 2009 H1N1 is very different from what normally circulates in North American pigs. It is said to be a cross between a pig flu, a human flu and also the bird flu, which has been deadly too. An influenza virus containing genes from a number of sources is called a “reassortant” virus.
Swine flu viruses are most commonly of the H1N1 subtype but other subtypes (H1N2, H3N1 and H3N) are also circulating. The H3N2 swine virus was thought to have been originally introduced into pigs by humans.
What are the similarities and differences of Swine flu and regular seasonal flu?
Generally clinical symptoms of swine flu are similar to seasonal flu including malaise, fever, cough, headache, muscle and joint pain, sore throat and runny nose. Sometimes vomiting and diarrhoea can be observed in the early stages of the swine flu.
Seasonal influenza can cause mild to severe illness, at times it lead to death also. Swine flu can cause death due to viral pneumonia and lung failure in a small proportion of people.
Swine flu spread in the same way that seasonal flu spreads. Flu viruses spread mainly from person to person through coughing, sneezing or talking by people with influenza. Sometimes people may become infected by touching something like a surface or object with these viruses on it and then touching their mouth or nose.
Swine flu affects the people younger than 65 years of age more severely than people older than 65. This pattern was not observed with seasonal flu.
Swine flu may cause complications in high risk group people such as; children, patients with chronic respiratory conditions, pregnant women, patients who are obese (BMI >30), indigenous people and patients with chronic cardiac, neurological and immune conditions.