An apparent cluster of aplastic anemia in a small population of teenagers.

Four teenagers with severe aplastic anemia, initially diagnosed and evaluated over a seven-year period at The Johns Hopkins Bone Marrow Transplant Unit, Baltimore, were residents of the same small town in South Carolina. Estimated annual incidence for that age group in the town, based on the four cases, was 100 times the expected rate. All four of the teenagers had attended one of two junior high schools. An exploratory survey of all high-school students, comparing risk factors of those who had attended the "affected" junior high school with those who had attended the "unaffected" junior high school, showed no associations with exposure to glue, paint or varnishes, pesticides, history of hepatitis or infectious mononucleosis, or use of chloramphenicol or other suspected drugs. Weak associations were found between the affected junior high school and employment in the textile industry and in agriculture (specifically peach orchards).