Anaerobe (1999) 5, 171±172 Article No. anae.1999.0214
BOTULISM (ORAL PRESENTATION)
Outbreak of Type E Botulism Associated with Home-cured Ham Consumption F. Rosetti*, E. Castelli, J. Labbe¨, and R. Funes INEI-INPB-ANLIS Carlos G. MalbraÂn, Av. VeÂlez Sarsfield 563, (1281), Capital Federal, Argentina
Key Words: botulism, ham
Many consumers in Argentina purchase homemade foods for perceived advantages in flavor and cost. Though preparation of preserved foods at home is not substantially different from industrial manufacture, home preparation is not subject to industrial measures of hygiene and quality control. As a result, homemade foods carry a higher risk of contamination. An unusual outbreak of type E botulism associated with homemade ham is presented herein. In September 1997, a family in Buenos Aires province dined at a luncheon of home-cured prosciutto ham, grilled river fish, home-preserved eggplant in oil and vanilla ice cream. A luncheon guest experienced symptoms and signs of botulism 18 h later and was hospitalized. An additional five diners were admitted to a second hospital in the following hours. Their symptoms included nausea and abdominal pain, blurred and double vision, photophobia, ptosis, respiratory impairment, muscle cramps and weakness. The ages of the patients ranged from 14 to 77 years. While all six reported consuming ham at the
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luncheon, only some of them had eaten eggplant or fish. Nearby workers were offered sandwiches containing the ham served at the luncheon. The pig that was the source of the ham was also used for sausage and bacon which had not been served at the lunch. Serum, gastric aspirate and enema samples were obtained from the hospitalized patients. Serum was obtained from others who had also eaten the ham but were not hospitalized. Samples of all of the lucheon foods and of the sausage and bacon were obtained. A mouse (weight 18 to 20 g) bioassay was used to detect botulinum toxin in serum, gastric aspirate and enema samples, food specimens and bacterial cultures. Botulinum toxin type was determined by neutralization with monovalent antitoxin. Food, gastric and enema samples were treated with 1 mL of cold gelatin diluent for each gram of sample then centrifuged for 20 min at 12 0006g while refrigerated. Supernatant was filtered and tested, with and without trypsinization, for the presence of botulinium toxin. Samples were also cultivated in Tarozzi medium for 5 days at 378C with and without previous heating at 608C for 10 min. Culture supernatant was filtered and tested for neurotoxin as above. Clinical specimens from the six patients and the prosciutto ham contained type E botulinum toxin. Trypsinization of samples increased the toxicity. No # 1999 Academic Press
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toxin was detected in serum from subjects who had eaten ham but who had not been hospitalized. Clostridium botulinum type E was isolated from gastric aspirate and enema samples and the ham. C. botulinum was not detected in the grilled river fish, home-preserved eggplant, vanilla ice cream or in the sausage and bacon prepared from the same pig. In summary, the first confirmed outbreak of type E botulism in Argentina was recognized. Unlike most outbreaks of type E botulism, which have been associated with eating fish or other aquatic animals, this outbreak was associated with eating home-cured prosciutto ham. The presence of type E C. botulinum and neurotoxin in the ham, but not the sausage or bacon from the same pig, suggests the possibility that
the seasoning for the ham was contaminated with C. botulinum.
Reference 1. CDC (1979) (CDC Botulism in United States (1899±1977). Handbook for Epidemiologists. Clinicians and Laboratory Workers. US Department of Health ± CDC, Atlanta 2. Weber J.T., Hibbs R.G., Darwish A., Mishu B., Corwin A.L., Rakha M., Hatheway C.L., El Sharkawy S., El-Rahim S.A., AlHamd M.F.S., Sarn J.E., Blake P.A. and Tauxe R.V. (1993) Massive outbreak of type E botulism associated with traditional salted fish in Cairo. J Infect Dis 167: 451± 454 3. Piersante G.P., Marino A., Fenicia L., Moro M.L. and Aureli P. (1995) Un esteso episodio di botulismo da prosciutto crudo stagionato di produzione casalinga. Ann lg 7: 451± 458
