H1N1 is a swine flu that has caused a worldwide panic in year 2009.  Before that in, 1918, Spanish flu took away lives of millions.

Most of us consider influenza as a respiratory disease commonly caused by virus. For years, it has created a pandemic scare due to its easy transmission. Here are some facts about influenza.

Fact 1: Signs and Symptoms:

People with influenza suffer from fever, cough, runny nose, headache, and muscle pains. Common colds are used interchangeably with influenza, however they have an entirely different etiology. Colds is a less serious illness, with an expected span of two days. Usual cause is an irritant like dust, pollens or sudden change in the climate different from the temperature the body is accustomed to. It is not always accompanied by fever and myalgia. Influenza on the other hand is more severe. The source of this infection is a virus and it lasts for almost a week.

Fact 2: Complications:

An influenza left untreated can lead to pneumonia. Due to serious inflammation of the respiratory tract, pus cells will fill the air sacs blocking the delivery of oxygen in the bloodstream. Aftermath of the flu could also lead to Reye’s syndrome, swelling of the brain and liver, which is a disease that usually occurs after viral infections. Guillain-Barre is another complication where nerves are attacked by the immune system.

Fact 3: Transmission:

Transmission of influenza is more widespread because it is through inhalation of infected respiratory droplets.

Fact 4: Cure and Prevention:

The disease is usually self limiting but symptoms could be treated using over the counter drugs. Influenza could be prevented through avoiding crowded places or protective equipment like masks. Vaccines for flu have already been manufactured to give you an antibody against a specific strain of virus. However, shots should be taken every year because the gene code of the virus shuffle and it creates a new strain that is not recognized by the immune system.

Fact 4: Laboratory Diagnosis

RT-PCR (Reverse Trancriptase Polymerase Chain Reaction) is a laboratory test that identifies the strain of the virus. Antigen could also be identified though serological tests like ELISA (Enzyme Linked Immunosorbent Assay) and IF (Immuno Fluorescence.) Cell culture could be performed, by using primary monkey kidney cells or Mardin Darby Canine Kidney Cells.

Fact 5: Cause of Influenza

The virus that causes influenza belongs to the family of Orthomyxoviridae. It is an RNA, helical, enveloped virus with 8 segments. It is classified in to 3 major antigenic groups, depending on the content of their RNP (ribonucleoprotein): Influenza A, B, and C. The subtypes or strains are classified according to the structure of their (NA) neuraminidase and (HA) hemagglutinin. HA functions as the attachment to the cell while NA cleaves the sialic acid to facilitate the release of virus in the cell.

Fact 6: Genetic Assortment:

Influenza undergoes rearrangement of their genetic make-up through two mechanisms: shift and drift. Shift is a major change that results to pandemic scare. Influenza from man and bird will enter a pig. The protein NA and HA of both strains from different species will regroup inside the body of the pig. Once it goes out of the body of the pig and infect a bird or a man, it will be an entirely new strain. Our immune system does not recognize this new strain and previous vaccine shots will be of no use. Luckily shift happens only after every 10 years. Drift on the other hand is a more frequent change that happens almost every year but it results to less antigenic variation. No protein is changed, and same genes are only rearranged from their positions. Drift causes less serious illness.