PRAGUE -- Fatima, who lives in western Tanzania near Lake Tanganyika, has been suffering for more than a month from a dry, hacking cough. She trembles to think that it might mean she has tuberculosis. Fatima knows that she can find out and, if necessary, receive treatment at the nearest health clinic, a one-hour bus ride away. She ponders asking her husband for the bus fare (about 60 euro), but decides against it. She needs this money to feed her children. Besides, if she tests positive for TB, her husband and all of their neighbors will assume she also has AIDS.