By: Liz Szabo | Source: USA Today | April 27, 2009

It’s a common respiratory ailment in pigs, but this strain appears to be a subtype never before seen in pigs or humans. Here are answers to questions you may have about swine flu.

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: 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: 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 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 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.

Q: Why has the virus been so much deadlier in Mexico, where 1,300 have become ill and more than 80 people have died, than in the USA?

A: “What we’ve seen in this country is not anywhere near the severity of what we’re seeing in Mexico,” Besser said. Doctors don’t yet know why cases have been milder in the USA, where only person has been hospitalized, although 20 cases have been confirmed, Besser said.