Drawing on 17 months of ethnographic fieldwork in Freetown, Sierra Leone, I highlight the recursive relationship between Sierra Leone as an exemplary setting and HIV as an exceptional disease. Through this relationship, I examine how HIV-positive individuals rely on both enumerative knowledge (seroprevalence rates) and vernacular accounting (NGO narratives of vulnerability) to communicate the uniqueness of their experience as HIV sufferers and to demarcate the boundaries of their status.