Abstract
Even one case of foodborne botulism constitutes a public health emergency. We report a series of cases with delayed treatment due to delayed diagnosis. Clostridium botulinum type A(B) was isolated from vegetarian home-canned pate, but not from stool samples. These are the first recorded cases of foodborne botulism in Hanoi.
Introduction
Botulism is a rare but serious neuroparalytic illness caused by botulinum neurotoxins (BoNTs) [1,2]. The sources of BoNTs are Clostridium botulinum and sometimes C. butyricum, C. baratii, and C. argentinense. The toxins are produced under anaerobic conditions and act presynaptically at peripheral cholinergic neuromuscular junctions, blocking acetylcholine release. Seven types (A–G) of BoNTs have been identified [3]. The classical early signs of botulism include cranial nerve palsies that progress to the symmetrical descending weakness of the trunk, extremities, and smooth muscle, with eventual flaccid paralysis. Typical early symptoms include diplopia (visual disturbances), dysphagia (difficulty swallowing), dysphonia (voice change), and dysarthria (slurred speech) [4]. Considering the severity and potential public health impact of this disease, rapid diagnosis is necessary. This report describes the first recorded cases of foodborne botulism in Hanoi, associated with vegetarian home-canned pate. This was caused by C. botulinum type A(B), which carries both type A and type B bont genes but does not produce active type B toxin because of mutations or truncations.