Wound botulism in California, 1951-1998: Recent epidemic in heroin injectors

California has reported most of the world's wound botulism (WB) cases and n early three-fourths of the cases reported in the United St-aces. We reviewe d the clinical, epidemiologic, and laboratory features of WE. From the firs t case in 1951, through 1998, a total of 127 cases were identified-93 in th e last 5 years. The dramatic increase has been due to an epidemic (of WB) i n people who inject black tar heroin. Whereas early cases of WE occurred af ter gross trauma, all but I of the last 102 cases occurred in drug users, p rimarily those who inject drugs subcutaneously ("skin poppers"). Cases are occurring disproportionately in Hispanics and women. Misdiagnosis and diagn ostic delays of up to 64 days have occurred. This unprecedented, ongoing ep idemic is now being reported in other stales. We discuss the clinical and l aboratory features that distinguish botulism from conditions that can mimic it, the relative yield of various diagnostic laboratory tests for botulism , and its treatment.