Headlines - Human Botulism in France, 2010–2012

Human botulism is a rare but serious neurological condition that has been a reportable disease since 1986. Since 1998, the National Reference Center for Anaerobic Bacteria and Botulism has participated in the surveillance of human botulism by reporting biologically confirmed cases to the InVS. The laboratory diagnosis is based on the detection of botulinum toxin in patients’ serum. A report on the situation of human botulism in France between 2010 and 2012 is published in this week’s Weekly Epidemiological Bulletin. In total, 24 botulism outbreaks involving 51 cases were identified. The diagnosis of botulism was confirmed for 22 of the 24 outbreaks (92%): 11 type A outbreaks (23 cases), 10 type B outbreaks (24 cases), and 1 type E outbreak (1 case). Among the 51 cases, the most frequently reported symptoms were diplopia (60%) and dysphagia (59%), followed by dry mouth (48%) and vomiting (47%). All cases of type A botulism were severe, requiring hospitalization and intensive care with mechanical ventilation in 77% of them, and one death. The cases of botulism were primarily foodborne (48 out of 51 cases, representing 21 outbreaks). Two cases of infant botulism (3 and 5 months old) and one case of botulism due to intestinal colonization by Clostridium botulinum in a 10-year-old child were also reported. Foodborne origin was biologically confirmed in 14 of the 21 outbreaks: home-prepared foods in 10 outbreaks and commercially available products in the other 4. Outbreaks of botulism caused by a commercially available product were primarily type A and all involved very severe cases. The small number of outbreaks does not allow for the identification of specific geographic areas prone to botulism. However, considering all cases occurring during the 1991–2012 period, a significantly higher incidence can be observed in Saône-et-Loire as well as in three other departments in central France (Allier, Indre, and Vienne), linked to local dietary habits, particularly the consumption of charcuterie products that have not undergone sufficient heat treatment, such as raw and dried ham and other cured meats.