The aim of this case review is to recognize the unique clinical course and treatment of neonatal botulism caused by Clostridium baratii and associated botulinum toxin F (BoNT/F).

An 11-day old infant presented with acute respiratory failure. Within hours of arrival to the NICU, he progressed from an initially normal neurologic exam to diffuse hypotonia, dilated and sluggish pupils, and loss of muscle and most primitive reflexes. He had rapid improvement within 4 days after symptom onset. On DOL 15, electrophysiologic testing supported infant botulism, and he received BabyBIG. Care of the patient was coordinated closely with the California Department of Public Health (CDPH).

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Initial septic, genetic/metabolic, and traumatic workups were largely unremarkable including normal MRI brain and spine, MR spectroscopy showing nonspecific delayed maturation versus hypomyelination, and CSF with high-normal protein and no pleocytosis. 

Nerve conduction study showed small/borderline motor amplitudes without features of demyelination, with normal and robust sensory amplitudes. Needle electromyography showed very small low amplitude motor unit potentials (MUP) suggesting early recruitment for age. MUPs showed unstable configurations, suggesting a neuromuscular junction transmission defect. 

A preliminary positive for BoNT/F in the stool was reported on DOL 17.

BabyBIG does not cover BoNT/F, so it was theorized that it would not be an effective treatment of this patient’s infection. Heptavalent botulism antitoxin (HBAT) administration was discussed in consultation with the CDPH, but was not administered initially due to clinical improvement. However, on DOL 26 after a subsequent episode of neurologic and respiratory decline requiring intubation, he received HBAT. He had a gradual response to treatment starting 24 hours post-infusion. He was discharged on DOL 42, with no further recrudescence of symptoms. As of 7 months of age, his gross motor development has largely normalized, and he continues to refine his fine motor and oral skills.