Introduction Swine Influenza is a group of influenza viruses that affect pigs. There are four main types of it, but like all human influenza viruses, swine influenza viruses change constantly. Human infections are uncommon, but have occurred in the past. Human infections with swine flu are more common in individuals who have direct exposure (close contact) with pigs. The new strain that began circulating in April 2009 can move from person to person, and so more people than usual are being infected. If a swine flu virus mutates to a form that can move from person-to person , it is likely to spread in the same ways traditional seasonal flu spreads between people. It's called “droplet” spread. When an infectious individual coughs, sneezes, talks, etc. they expel contaminated droplets. If these droplets get into someone else's mouth, eyes or nose, that person can become infected with the flu. This is why personal hygiene is critical to staying well. Definition Swine influenza (also...