When Home Cooking Turns Hazardous: Two Botulism Cases
Authors:   Ospedale Evangelico Betania, Italy, Nasti Rodolfo 
Published: December 2024

Introduction: Botulism is a rare, potentially life-threatening
neurotoxin-mediated disease caused by the anaerobic, grampositive bacterium Clostridium botulinum, and occasionally by
related species such as C. baratii and C. butyricum. The diagnosis
of botulism relies on clinical suspicion and a comprehensive
neurologic examination. Timely diagnosis is crucial.
Case Report: A 62-year-old woman presented to our department
with diplopia, dysarthria, dysphagia, and hoarseness, which had
developed over the past four days. She had a recent history of
vomiting 48 hours after consuming homemade pumpkin preserves,
followed by the onset of dysphagia, diplopia, dysarthria, and
hoarseness 48 hours later. Neurological examination revealed
dysphonia with a “hoarse” voice and an asymmetry of the
pharyngeal reflex, more pronounced on the right. Laboratory tests
showed no significant abnormalities. Brain CT scan results were
unremarkable. Botulinum toxins were detected in her blood, and
botulinum toxin-producing clostridia were found in rectal swabs.
A diagnosis of foodborne botulism was established, and botulinum
antitoxin was administered. The patient’s symptoms improved
rapidly, with diplopia being the only persisting symptom. She was
discharged after 7 days with indications for orthoptic rehabilitation.
Several days later, the patient’s husband, who had also consumed
the homemade preserve, was admitted to the emergency room with
similar symptoms, including constipation, dysphagia, dysarthria,
diplopia, and eyelid ptosis. Botulinum toxins were not detected in
his blood, but botulinum toxin-producing clostridia were found
in rectal swabs. He received antibotulinum serum, leading to
symptom improvement. He was discharged after five days with
mild eyelid ptosis, and orthoptic rehabilitation was recommended.
Discussion: Foodborne botulism is diagnosed based on
neuromuscular symptoms and a history of ingesting potentially
contaminated food. Simultaneous symptom onset in individuals
who consumed the same food supports the diagnosis, which can
be confirmed through the detection of C. botulinum toxin in serum
or feces. Botulinum toxins are highly resistant to degradation and
can be found in various types of food, particularly in homemade
canned goods with low acidity and occasionally in commercially
prepared foods.
Symptoms of foodborne botulism typically begin 18-36 hours
after toxin ingestion, with an incubation period ranging from 4
hours to 8 days. Treatment primarily consists of supportive care
and botulinum antitoxin administration. Administering antitoxin
early in the illness course improves outcomes, while delays can
be less effective. It’s important to report all patients receiving
antitoxin to health authorities.
The heptavalent antitoxin, derived from horse serum, carries
a risk of anaphylaxis or serum disease [1-7]. Immunity does
not develop after infection, and new recombinant vaccines are
under investigation. The administration of botulinum antitoxin
reduces mortality, duration of intensive care unit treatment, and
hospitalization duration.