A 5-month-old previously well infant was taken to the emergency department because of parental concerns about constipation and feeding difficulties. She was born at term and had passed meconium within 24 hours. She had been having daily bowel movements, but at the time of assessment she had not had one in 15 days. She was breastfeeding poorly and was drooling more than usual. Her parents also noticed that she was weak in both the upper and lower extremities and was no longer able to roll over. She had no fever, upper respiratory or other gastrointestinal symptoms.
The pregnancy had been unremarkable. The infant was delivered at home with the help of a midwife. Her birth weight was 4.3 kg. She was breastfed exclusively, with no ingestion of solid foods or honey. She had not had any illnesses or need of hospital care. She was not vaccinated because of parental preference. The family was living in a house in a rural area in Canada.
On initial physical examination, the infant appeared well. Her vital signs were normal, and she had no signs of distress. The findings of a systemic examination in the emergency department were normal. There were no signs of gastrointestinal obstruction, and the rectal examination showed no abnormalities. Constipation was diagnosed, and the infant was discharged home.
After 5 days of persistent constipation, weakness and poor muscle tone, and 3 separate outpatient medical assessments, the girl was referred to the emergency department and admitted to hospital for monitoring and further investigation. Laboratory tests showed a normal complete blood count, electrolyte levels and metabolic test results, including normal lactate, ammonia and blood gas levels. Lumbar puncture revealed a leukocyte count of 3 × 106/L, an erythrocyte count of 1 × 106/L, a protein level of 0.2 g/L and a glucose level of 2.7 mmol/L, all within normal limits. Cultures of blood, urine and cerebral spinal fluid were negative for bacteria. Magnetic resonance imaging of the brain showed no abnormalities.
Because of the presence of constipation together with neurologic findings of peripheral hypotonia and bulbar involvement, as suggested by the feeding difficulties and excessive drooling, a diagnosis of infant botulism was considered by the admitting physician. A fecal sample was sent to Health Canada’s Botulism Reference Service for Canada. It tested positive for botulinum neurotoxin type A. Polymerase chain reaction assay was positive for the type A neurotoxin gene, and an enrichment culture yielded Clostridium botulinum type A.
Given the patient’s clinical presentation and the detection of toxin in the fecal sample, infant botulism was diagnosed on day 4 of admission. The patient breastfed throughout her hospital stay, requiring only 48 hours of feeding through a nasogastric tube. She had no signs of respiratory compromise and gradually showed improvement in the power in her limbs. Given her clinical improvement at the time of diagnosis, her prolonged history and mild presentation, she was not given antitoxin. It was decided to observe her in hospital and consider antitoxin if she required antibiotic therapy for a secondary bacterial infection.
On discharge home after 7 days, the patient had only mild weakness, was feeding well and had no further excessive drooling. Over the next few weeks, she made a complete recovery to baseline neurologic and developmental status. Culture of honey products from her home were negative for C. botulinum; no other household products were tested.