Most staff members at the Harvard AIDS Initiative could tell you that 24% of the adult population in Botswana is HIV-positive. Yet most couldn’t tell you how many people in Massachusetts, with a population of 6.4 million, are living with HIV/AIDS. The answer, according to 2007 statistics, is 16,866. To acknowledge that AIDS is a local, as well as an international problem, a dozen staff members took part in the…