This week, olives from several different companies were found to contain Clostridium Botulinum. No cases of botulism have been reported to date, but this is an opportunity to review the pertinent clinical findings.
Botulism is caused by exposure to the botulinum neurotoxin in clostridium botulinum. There are eight toxin strains identified, 4 are known to cause disease in humans. The toxin is produced only in an anaerobic environment, so bottled or canned food products are a good source of infection. Food may smell putrid when opening the product, but the FDA warns that in this present outbreak, the olives smell and look normal.
Onset of symptoms usually occurs within 12 to 36 hours of ingestion, but patients can present within hours or as late as one week later. The toxin irreversibly binds to nerve endings to prevent release of acetylcholine into the synaptic space. The quicker symptoms develop, the more severe the course. Patients initially present with severe fatigue and bulbar findings such as diplopia, dysarthria and dry mouth. Symptoms progress rapidly to flaccid paralysis, vomiting, and ileus. Patients usually die of respiratory failure. Diagnosis can be made by assayed toxin in stool and blood. It also shows a distinct pattern on EMG.
If the patient can be mechanically ventilated, he or she may recover neurologic function over a period of weeks. Patients who are diagnosed at an early stage may clinically respond to equine-derived trivalent antitoxin, which has fc portion bound and therefore is more immunogenic. A second antitoxin is 7-valent and has the fc portion cleaved, therefore inducing less of an immune response in the patient. If ICU care is not available, mortality rates are as high as 70%. If the patient has access to ICU care, the mortality rate can be as low as 5%.
In this situation, the olives have all originated from a specific company in Italy. The FDA has issued this warning because they are of the opinion that the Italian company is not appropriately informing the American companies that their product is tainted. Other food products can be decontaminated from c. botulinum toxin by being cooked to 121 degrees Celsius.
Let’s not forget the therapeutic uses of botulinum toxin. The Oscars would not be what they are today without a little “botox”.
Bartlet, J. Botulism Cecil Textbook of Medicine, Chapter 320 pp. 1838-1840, 2004. http://www.mdconsult.com.ezproxy.med.nyu.edu/about/book/72111967-3/instruct.html?DOCID=1231
image courtesy of wikipedia
Commentary by Deborah Shapiro, M.D. Attending Physician, Dept. Veterans Affairs