Swine flu viruses do not usually infect people. CDC gets only about one report of swine flu virus in a person each year. Usually, these infections happen in people who have contact with pigs (farmers who have pig herds, for example). There have been rare cases of one person spreading swine flu to people. The symptoms of swine flu in people are the same as seasonal human flu and include a fever with a cough and/or sore throat, body aches, and tiredness. You can also become infected with swine flu and never have symptoms. Blood tests may determine whether you have ever been infected with swine flu. People may be at risk for complications from flu (like pneumonia) especially those who are very young, elderly or have some medical conditions and these people should get a flu shot every year.