Primary HIV infection occurs within 20 days to 8 weeks following exposure to HIV. The symptoms of primary HIV infection are usually fever, tiredness, headache, or muscle aches. However, symptoms vary greatly from person to person, and some people might not experience any symptoms at all. Because these symptoms also resemble the cold or the flu, it is difficult to identify patients with primary HIV infection. Information gathered from this study will help doctors decide what kind of treatment is best to give patients who recently have been infected.