The Elements
The swine flu virus, also called H1N1, consists of human, bird and swine genetics. It can be found in saliva, eye secretions and mouth secretions. The virus is thought to only be spread from human to human, according to the Centers for Disease Control and Prevention. It only takes one ill person to infect many others. A person who has gotten a swine flu vaccine has a greatly diminished chance of contracting the virus.
Contact
The infectious substances can be spread through the air, via coughing or sneezing. Saliva droplets, or other secretions that contain the virus, can land on an object and be picked up by another person. A person who is seemingly healthy can touch the object contaminated by the infectious substance and become infected with the swine flu. He would have to rub his eyes, nose or mouth in order to allow the virus to enter his body. He can also inhale the spittle particles an ill person coughs or sneezes out into the air. This is why Johns Hopkins Medical Center strongly encourages frequent hand washing to remove any contaminants picked up by the hands. Simply touching the flu-containing germs won't cause a person to be ill.
Infection
Once the virus has entered the body, it can multiply into millions of new virus cells, according to NPR.org. It can take up to 24 hours for symptoms of illness to appear. These usually include fever, coughing, general weakness, fatigue, headache, muscle and body pains and/or vomiting and nausea. The virus can get lodged into the mucus membranes for a brief period before it's able to infect a person's cells and make her ill. A strong immune system can also fight off virus cells, making the illness milder or short-lived. Once a person has contracted the virus and it begins replicating, she becomes contagious and the cycle starts over.
