Botulism: A Measurement of Occurrence

 Botulism, caused by the Clostridium botulinum bacterium, is typically caused by poorly prepared, home-canned foods and can cause symptoms as simple as blurred or double vision to full body paralysis, sometimes causing death (Centers for Disease Control and Prevention [CDC], 1996). The incidence of botulism is said to be extremely low with only 126 reported cases in the United States in 2003; with only eight attributable to foodborne vectors, the predominant cause is accidental contamination (CDC, 2004).

One of the concerns regarding botulism is its toxicity. Botulinum toxin is the most potent toxin known to man (CDC, 2006). This potency lends to botulinum’s ability to be used as an agent of bioterrorism, though most of the known cases have been shown to be accidental in nature (CDC, 1996; CDC, 2006). Another concern is the accidental or negligent contamination of any food prepared for wide distribution, such as canned vegetables from a large manufacturer.

Surveillance is important to identify each and every case in order to have the most accuracy possible when considering increasing or decreasing trends of incidence and prevalence of the disease. The cause of any increase or decrease in incidence of botulism should always be investigated.

Any increase of incidence could identify a possible problem while a decreased incidence could foretell efficacy in the efforts of mitigation. More appropriately, though, as Friis and Sellers (2009) show, further identification should be made in order to focus on specific descriptive factors, such as affected populations, the geography of these populations, known vectors, and factors of time. This process will ensure that more accurate trends are observed.

For instance, the CDC (2004) has stated that in a typical year, such as 2004, the incidence of botulism is less than 200. With incidence reporting covering the entire United States, increases or decreases in this crude number serve only to identify general changes in frequency; whereas, further identification of certain characteristics of the disease pattern will help to further isolate affected individuals and etiologies (Friis et al., 2009). Within the CDC’s (2004) data, infant occurrence of botulism is identified as the major contributor to incidence, thereby isolating the remaining occurrences to adults. The CDC has gone further to separate the incidences of botulism into three groups, infant occurrence, foodborne infection, and wound infection. A separate group is reserved for other occurrences relating to the use of pharmacological botulin.

Using descriptive factoring of the 2003 CDC data (2004), further geographic isolation of occurrences show that infant occurring botulism is fairly wide-spread with a small number of incidences in each of twenty-two States, though California and Pennsylvania account for about half of the reported infant occurrences. Foodborne and wound occurrences of botulism were isolated to Alaska, California, Colorado, Oregon, Utah, and Washington. Texas had the only two reportable cases classified as “Other”. Theoretical assumptions can now be used to show that the problem in Texas is resolved but should continue to be monitored, and food safety education projects should focus on home-canning in the western regions of the United States.

In conclusion, epidemiology is an important means of understanding and identifying causation and etiology, as well as preparing for mitigation and outbreak response. In this example of botulism, I have identified localization of the disease, common pathways of infection, or vectors, and means of helping to mitigate future occurrences of the disease. Botulism numbers are quite low, but dealing with other diseases of larger scale, grouping the data into useful subsets will assist in following the progression of the disease from outbreak to outbreak and in consideration of mitigation techniques employed.


Centers for Disease Control and Prevention, U. S. Department of Health and Human Services. (1996). Botulism (Clostridium botulinum): 1996 case definition [CSTE Position Statement No. 09-ID-29]. Retrieved from

Centers for Disease Control and Prevention, U. S. Department of Health and Human Services. (2004). Surveillance for Outbreaks of Botulism [Summary of 2003 Data]. Retrieved from the Centers for Disease Control and Prevention website:

Centers for Disease Control and Prevention, U. S. Department of Health and Human Services. (2006). History of Bioterrorism: Botulism. CDC Emergency Preparedness and You [Podcast]. Washington, DC: CDC Bioterrorism Preparedness and Response Program.

Friis, R. H., & Sellers, T. A. (2009). Epidemiology for public health practice (4th ed.). Sudbury, MA: Jones & Bartlett.