Botulism causes skeletal-muscle weakness resulting from bacterial exotoxins that irreversibly block the release of acetylcholine from presynaptic motor neurons. We report three cases of botulism in members of the Native American Church who consumed peyote, a cactus with hallucinogenic properties that has been legalized for sacramental use in traditional American Indian religious ceremonies.

Thirteen church members ingested peyote from a communal jar during a ceremony. Two to four days afterward, three men (40, 42, and 72 years old) noted the onset of bilaterally symmetric, moderate, flaccid weakness in all extremities. Two had nasal speech, dysphagia, and diplopia. Two of the patients consented to undergo electromyographic studies, the results of which were notable for markedly diminished amplitudes of all compound muscle action potentials, which increased greatly (40 to 82 percent) after exercise. This magnitude of increase has been observed in 85 percent of patients with botulism and indicates a presynaptic defect of the neuromuscular junction, thus supporting the clinical diagnosis of botulism.

Field nurses from the Public Health Service recovered the peyote, which was found to contain type B botulinum toxin in a bioassay in which the administration of neutralizing antibodies prevented the paralytic death of mice (Centers for Disease Control and Prevention, Botulism Laboratory, Atlanta). Serum specimens from two patients were negative for the toxin, a common finding when there is a delay in testing. The stool of one patient contained a toxin that could not be typed. Ingestion histories were unrevealing, and none of the freshly prepared food the patients consumed could be recovered for testing. All three patients recovered within the time expected for the production of new presynaptic terminals. One patient required hospital observation and parenteral nutrition for 14 days, then slowly recovered by 2 to 3 months; the second refused admission despite his dysphagia but also recovered within the expected time frame; the third was only mildly affected and recovered after 4 weeks. None required antibotulinum toxin, which is reserved for patients whose condition deteriorates seriously after ingestion of the botulinum toxin.

The ceremonial tea the patients had drunk was made from buttons of the dried, alkaline-ground peyote cactus, which had been covered with water and stored in a closed jar for two months under refrigeration. We believe that this prolonged, nontraditional storage of unsterilized peyote produced an anaerobic and alkaline environment that favored the growth and production of toxin from spores of Clostridium botulinum that were probably on the cactus. These cases of botulism from peyote illustrate that all ingested substances, including herbal medications and religious sacraments, must be considered as sources when botulism is suspected.