Pauci-symptomatic foodborne botulism due to Clostridium botulinum type B with predominant ophthalmologic presentation possibly after consumption of honey

Foodborne botulism, a toxin-mediated illness caused by Clostridium botulinum, is a public health emergency, and rarely reported in France. We report herein the case of two family members (a father and his son) from Franche-Comté, France, presented with ophthalmological symptoms which occurred after non-specific gastro-intestinal symptoms after a trip to Serbia with a recent consumption of artisanal honey, and suggestive of botulism. The suspected intoxication appeared to be caused by a type B strain of C. botulinum, as demonstrated by toxin-neutralization in the lethal mouse bioassay. Regarding the mild-to-moderate form, the patients were treated symptomatically with monitoring, against antitoxins, with no evidence of relapse afterwards. We want to highlight the importance of recognizing clinical ophthalmologic botulism symptoms as unreactive bilateral mydriasis with lack of accommodation to contribute to earlier diagnosis in case of pauci-symptomatic botulism.