This figure is based on data from King County, Washington, in the early 1980s and indicates that there are 1,000 cases of HUS in the United States per year or an average of 2.8 cases per day in a population of 250 million. The Centers for Disease Control and Prevention has recently reported that only half of the country's microbiologists screen for this organism. C. botulinum is an unusual foodborne pathogen in that it causes neuroparalytic rather than diarrheal disease. The toxin can enter into foods, but in recent years, C. botulinum has also been found to colonize the intestinal tract of infants under 1 year of age and of adults that have undergone intestinal surgery or have been treated with antibiotics. The number of cases of adults with unusual clostridia that produce botulinum toxin is increasing.
Botulism occurs worldwide.
New food processes and packaging have been associated with the reemergence of botulism. A clam chowder outbreak in California involved a boxed food that was not properly stored. Baking had eliminated vegetative organisms, but the spores of botulinum were not killed. In this case, a low-acid food was held under anaerobic conditions. Botulism outbreaks are probably the most reported type of foodborne illness.