context: CDC: The Centers for Disease Control and Prevention, a branch of the Department of Health and Human Services. The Atlanta-based federal agency helps promote and protect your health by finding ways to control and prevent injury, disability, and disease, including swine flu. It responds to public health emergencies and helps states create a response. Confirmed case: An illness in one person that is confirmed by a lab test or by linking it to another case that was confirmed in a lab. A case can be confirmed if the person was exposed to a known, contagious infection. For example, if tests show a child in your household has swine flu, and you get the same symptoms, you would be a confirmed case. Epidemic: An outbreak of an infectious disease that affects more people than expected. The disease spreads rapidly from person to person. Hybrid flu: A disease created when genes from animal influenza viruses mix with human flu viruses. For example, one virus that causes swine flu is believed to be a mix of pig, bird (avian), and human flu viruses. These types of viruses caused huge outbreaks in 1957, 1968, and 2009. H1 N1 virus: The most common subtype of influenza A, including the swine flu virus. The Department of Homeland Security and the Department of Agriculture call swine flu the H1 N1 virus so outbreaks won't stop people from eating pork products. You can't get the virus from eating well-cooked pork. But you should wash your hands after you visit a petting zoo or touch pigs. Pandemic: An outbreak that affects the entire world. Type A influenza viruses are the only ones known to have caused pandemics. In 1918, the Spanish flu pandemic killed 40-50 million people worldwide. Swine flu caused severe illness worldwide in 2009. Rapivab (peramivir): An antiviral drug that prevents and treats flu in adults aged 18 and over. It stops the virus from spreading in your body. This eases your symptoms and helps you get better sooner. You take it in one dose. Relenza ( zanamivir ): An antiviral drug that prevents and treats influenza types A (including the swine flu) and B. It stops the virus from spreading in your body. This eases your symptoms and can help you get better faster. It can treat the flu in people 7 and older and prevent it in those 5 and older. It isn't good for people with lung diseases like asthma or chronic obstructive pulmonary disease ( COPD). Swine flu symptoms: They're a lot like those that come with regular flu: fever, cough, sore throat, body aches, headache, chills, and fatigue. Some people with swine flu also have diarrhea and vomiting. Symptoms may be worse if you have another long-term illness. Swine influenza: A highly contagious disease caused by a strain of the influenza type A virus called H1 N1. Swine flu used to only affect pigs, or, rarely, people who spent a lot of time around pigs. In 2009 a strain began to spread from person to person. Swine flu treatment : Certain antiviral drugs can ease the symptoms and help you get better faster. The CDC recommends zanamivir ( Relenza), peramivir ( Rapivab), or oseltamivir ( Tamiflu) to treat and prevent this illness. The drugs may also help you avoid complications. They work best if you take them within 48 hours of the first symptoms. Swine flu virus: A virus found in pigs that causes swine influenza. The swine flu virus is different from the human type. There are many different strains of swine flu virus (such as H1 N1 and H3 N2). H1 N1 is the most common. Usually, a swine flu virus infects only pigs, or in rare cases, those around pigs. But in 2009, it began to spread from person to person. Tamiflu (oseltamivir): An antiviral medicine that prevents and treats influenza types A (including the swine flu) and B. It stops the virus from spreading in your body. This eases your symptoms and helps you get better faster. Anyone 1 year or older can take this drug to treat the flu. Anyone 2 weeks or older can get it to prevent the flu. Threat level: An alert system that the World Health Organization (see below) uses to let the public know about global health events. The scale ranges from phase 1 (low risk for a pandemic) to phase 6 (full-blown pandemic under way). Travel restrictions: Guidelines from worldwide health agencies that let you know when travel, like flying, to certain areas may put you at risk for disease. For example, in late April 2009, the CDC said people should only travel to Mexico if it was very important and not for vacation. This helped stop the spread of swine flu. Veracruz, Mexico: The origin of the 2009 swine flu outbreak. Health workers traced the virus to a pig farm in this southeastern Mexican state. A young boy who lived nearby was among the first people to contract the swine flu. He lived, but others in the area came down with the flu and died. World Health Organization ( WHO): The public health branch of the United Nations. The group stays on top of worldwide health trends and helps create standards to improve public health. It offers a pandemic warning system and gathers data on various diseases and outbreaks, including swine flu.