A 36-year-old man enters the hospital in an extremely debilitated condition. He has purple-brown skin lesions (a symptom of Kaposi’s sarcoma) and a persistent cough. A physical examination reveals swollen lymph nodes, and laboratory tests find a very low lymphocyte count. Information taken during the personal history reveals that he has multiple sex partners with whom he frequently engages in unprotected sex. What is likely to be the man’s problem and what is his outlook?