Antiviral	A medication that may be used to treat people who have been infected by a virus to help limit the impact of some symptoms and reduce the potential for serious complications. People who are in high risk groups are often given antiviral drugs because of their increased potential to develop additional health issues.
Communicable disease	An infectious disease that is contagious and which can be transmitted from one source to another by infectious bacteria or viral organisms.
Contagious disease	A very communicable disease capable of spreading rapidly from one person to another by contact or close proximity.
Epidemic	The rapid spread of a disease that infects some or many people in a community or region at the same time.
H1N1	H1N1, referred to as “swine flu” early on, is a new influenza virus causing illness in people. In the United States, this new virus was first detected in people in April 2009. This virus is spreading from person-to-person worldwide, probably in much the same way that regular seasonal influenza viruses spread. On June 11, 2009, the World Health Organization (WHO) signaled that a pandemic of H1N1 flu was underway.
H5N1 (avian) flu	Commonly known as bird flu, this strain of influenza virus is naturally occurring in birds. Wild birds can carry the virus and may not get sick from it; however, domestic birds may become infected by the virus and often die from it. The scientific name for a subtype of the avian influenza (bird flu) virus that has spread from birds to humans is H5N1. The scientific names for these subtypes are classified by different proteins on the virus. New subtypes naturally occur when the proteins change.
Infectious disease	A disease caused by a microorganism and therefore potentially infinitely transferable to new individuals. May or may not be communicable. Example of non communicable is disease caused by toxins from food poisoning or infection caused by toxins in the environment, such as tetanus.
Influenza (flu)	A contagious respiratory illness caused by particular strains of viruses.
Influenza Pandemic	A global outbreak of the influenza disease that occurs when a new influenza virus appears in the human population. Because people have little or no immunity to the new strain, serious illness can occur, and the virus can spread easily and rapidly from person to person with no vaccine immediately available.
Isolation	The physical separation of a person suffering from an infectious or contagious disease from others in a community.
Pandemic	An outbreak of a disease that affects large numbers of throughout the world.
Pandemic Influenza	A virulent influenza (flu) caused by a new flu virus strain to which humans have not been exposed. It is more serious than a typical seasonal flu because there is no natural resistance or immunity to it and infects large numbers of people of different ages all over the world, causing serious illness and possibly death.
Quarantine	The physical separation of healthy people who have been exposed to an infectious disease—for a period of time—from those who have not been exposed.
Seasonal Flu	A contagious respiratory illness caused by influenza (flu) viruses occurring every year. It affects an average of 5 to 20 percent of the U.S. population by causing mild to severe illness, and in some instances can lead to death. Most people have some immunity, and a vaccine is available.
Social Distancing	A disease prevention strategy in which a community imposes limits on social (face-to-face) interaction to reduce exposure to and transmission of a disease. These limitations could include, but are not limited to, school and work closures, cancellation of public gatherings and closure or limited mass transportation.
Vaccine	An injection, usually of an innocuous (weak or killed) form of the virus, which stimulates the production of antibodies by the immune system to help prevent or create resistance to an infection. Vaccines are usually given as a preventive measure.