What is Avian Flu?
Avian influenza is a type of influenza or "flu" that occurs in all species of birds. The virus that causes avian influenza - more commonly called "bird flu" - exists naturally in many wild birds, including wild waterfowl, without causing the condition in them; these birds are called carriers. Normally, the virus is associated with birds raised on poultry farms and less often, with pigs.
Avian influenza is rare in humans. When it does infect a human, the virus often causes serious illness or death. Recently, avian influenza has been getting more and more attention from medical authorities around the globe. A new subtype of the virus called H5N1 can cause disease with a high rate of mortality (death) in humans.
Almost all human cases of avian flu have come after close contact with live birds, on poultry farms or in regions experiencing avian flu outbreaks. Travel to certain countries may increase your odds of infection, especially if you visit poultry farms or markets selling live birds. Handling feathers or droppings may also expose you to the virus.
What is Mad Cow Disease?
Bovine Spongiform Encephalopathy (BSE), commonly known as Mad-Cow Disease, is a fatal, neurodegenerative disease in cattle, that causes a spongy degeneration in the brain and spinal cord. It is believed by most scientists that the disease may be transmitted to human beings who eat the brain or spinal cord of infected carcasses. In humans, it is known as new variant Creutzfeldt-Jakob disease.
What is SARS?
Severe acute respiratory syndrome (SARS) is a respiratory illness that was first reported in Asia in February 2003. Over the next few months, the illness spread to more than two dozen countries in North America, South America, Europe and Asia. According to World Health Organization, 8,437 people worldwide became sick with SARS during the course of this outbreak. Of those people who became sick, 813 died.
Most of the U.S. cases of SARS occurred among travelers returning from other parts of the world with SARS. There were very few cases as a result of spread to close contacts, such as family members and health-care workers. SARS did not spread more widely in the community in the United States.