The authors present data on 15 individuals infected by Panton-Valentine leukocidin (PVL) -producing strains of Staphylococcus aureus. Intra-familial spread was documented in one case, and occupational transmission was most likely in another case. spa typing of the strains revealed a broad range of variants, though some strains were clonally related. Methicillin-resistant Staphylococcus aureus (MRSA) was found in three cases.