Q: What is swine flu?
A: It's a common respiratory disease in pigs that doesn't usually spread to people. When pigs catch this flu, many get quite sick, and 1% to 4% die, according to the World Health Organization. In the past, people have sometimes caught swine flu if they worked directly with pigs.
Q: How is this swine flu virus different?
A: This strain appears to be a subtype not seen before in humans or pigs, with genetic material from pigs, bird and humans, according to WHO. Unlike most cases of swine flu, this one can spread from person to person, said Richard Besser, the acting director of the Centers for Disease Control and Prevention, at a White House press conference Sunday. One of the confirmed cases in the USA caught swine flu from a spouse, who had been to Mexico.
Q: How do you catch it?
A: You can get sick if someone coughs near you, because the disease spreads through microscopic respiratory droplets, says Martin Blaser, former president of the Infectious Disease Society of America. You also can get sick from touching a surface where droplets have landed, then touching your mouth or eyes. Although people are contagious before they show symptoms, they are most likely to spread the virus when they're coughing, Blaser says.
Q: Were pigs the carriers of this virus?
A: It's closer to say that pigs were the mixing bowl for this virus. Birds can't pass bird flu to people. But pigs are uniquely susceptible to getting flu viruses that infect birds. Experts have long worried that a pig would catch a bird strain of the flu and then the virus would mutate inside the pig to a form that could also infect other mammals. That may be what happened in this case. Pigs can also be infected with more than one influenza virus at a time, allowing the viruses to share genes, called "genetic reassortment," creating new and potentially much more virulent viruses.
Q: Can you catch swine flu from eating pork?
A: No, according to WHO. Pigs coming in to slaughter facilities are monitored for flu symptoms, and those that are ill are not allowed to enter the food supply. Cooking also kills the virus. People who work with pigs, however, can catch the virus. The Department of Agriculture is conducting tests to confirm that the food supply is safe, said Janet Napolitano, secretary of the Department of Homeland Security.
Q: What are the symptoms?
A: The most common symptoms are fever, fatigue, lack of appetite and coughing, although some people also develop a runny nose, sore throat, vomiting or diarrhea, according to the CDC.
Q: What should you do if you have these symptoms?
A: Stay home from work or school, to avoid spreading your illness to other people, Besser said. Don't get on an airplane. People should call their doctors to ask about the best treatment, but should not simply show up at a clinic or hospital that is unprepared for their arrival.
Q: How can people protect themselves?
A: As always, people should wash their hands frequently, Besser said. In the past, the CDC has said there isn't conclusive evidence to support using face masks. Surgical masks are designed to prevent the wearer from spreading germs, but may also catch large respiratory droplets if someone sneezes nearby. In a 2007 statement, the CDC said these masks could be worn if someone needs to go to a crowded place, such as a grocery store, for a short time. N95 respirator masks filter out 95% of particles to prevent the wearer from breathing them in. These must be fitted properly around the nose to create a seal, so they can make breathing difficult.
Q: What is the incubation period for the flu?
A: In most cases, infected people develop symptoms within one to four days.
Q: Should people who have recently traveled to Mexico be concerned?
A: Only if they have flulike symptoms, such as a fever, cough and body aches, or in some cases vomiting, says Thomas Tallman, head of emergency preparedness at the Cleveland Clinic. If it has been more than a week since you returned from Mexico and you aren't sick, you can relax.
Q: What should you do if you have flu symptoms?
A: Stay home. Don't go to work, school or travel until you've been free of symptoms for a day, Blaser says. If possible, ask in advance about working from home in case you or family members become ill. A small number of people are at higher risk, because they have been to Mexico — or have had close contact with someone who has.
Those who don't fit that profile probably have an ordinary flu, Tallman says. Most people can recover from the flu just fine at home. Stay in bed, drink lots of fluids and take acetaminophen for pain. Wash your hands frequently, and cover your mouth when you cough.
Q: When should you call the doctor?
A: If you're sick and have been to Mexico, or have close contact with someone who has, call your doctor for advice about being tested and treated, Tallman says. Patients should see a doctor if they have trouble breathing, vomit uncontrollably, become delirious or have other types of "altered mental status," says Mary Klotman, chief of infectious diseases at New York's Mount Sinai Medical Center.
Q: When should you use a mask?
A: There are two main types of masks.
• Simple surgical masks are designed to keep germs in — to prevent someone from coughing and spreading the virus.
• N95 respirator masks are designed to keep germs out and protect people from breathing in the flu virus.
In a 2007 statement, however, the CDC said there isn't definitive evidence that masks will keep people from getting sick. That's partly because respirators must be carefully fitted over the nose and mouth to ensure a tight seal, which can make it harder to breathe. Because the number of U.S. cases is still relatively small, there's no need right now for the general public to cover up.
Q: Is there a vaccine against swine flu?
A: No, but government scientists could try to create one, according to the CDC. "We've identified the virus," Besser said. "Should we decide to manufacture a vaccine, we can work toward that goal very quickly." CDC scientists don't know if this year's flu vaccine offers any protection.
Q: What about antivirals? Can they prevent swine flu?
A: This strain of swine flu does appear sensitive to the antiviral drugs Relenza and Tamiflu, but not to amantadine, or Symmetrel, and rimantadine, or Flumadine, Besser said. With normal seasonal flus, if taken within the first 48 hours after symptoms appear, antivirals can help people recover a day or two sooner. Doctors sometimes prescribe antivirals to household members of people with the flu to prevent them from getting sick.
Q: What does it mean for the government to declare a public health emergency?
A: While the declaration "sounds more severe than it is," Napolitano said Sunday, it will free up funds and allow health officials to use medications and tests that aren't normally used. The government also issued a public health declaration during recent floods in North Dakota and Minnesota, she said, and noted that the government often issues such declarations when hurricanes are approaching. The federal government is also releasing 25% of the 50 million doses of antiviral medications in the nation's Strategic National Stockpile, Napolitano said. The Department of Defense is also making 7 million doses available.
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