Prospective Study of AI H5N1 in China

The purpose of this study is to see if people in China who have contact with someone infected with bird flu (H5N1) become infected themselves without necessarily getting sick. Adults and children greater than 1 year of age who have contact with someone infected with bird flu may participate in the study. At the first 1-2 study visits, a blood sample will be taken from volunteers in order to test for antibodies, the part of the blood that fights infection. If the result of the H5N1 antibody test is positive after the 1st or 2nd study visit, an additional blood sample will be collected during a 3rd and 4th study visit. Volunteers will be asked questions about their work, home life, and possible contact with poultry, other birds, animals, and people infected with bird flu. Participants will be involved in study related procedures for up to 90 days.