Outpatient Infant Botulism in the United States, 1976-2021

Area of Science:

• Pediatrics
• Infectious Diseases
• Neurology

Background:

• Infant botulism (IB) is a rare but serious condition caused by *Clostridium botulinum* toxin.
• Most IB cases require hospitalization, but milder forms may present in outpatients.

Purpose of the Study:

• To characterize outpatient cases of infant botulism (IB) in the US.
• To understand the clinical presentation and diagnostic challenges of non-hospitalized IB infants.

Main Methods:

• Analysis of data from the Infant Botulism Treatment and Prevention Program (1976-2021).
• Definition of outpatient IB cases as those with clinical signs and laboratory confirmation, not requiring hospitalization.

Main Results:

• Only 17 (0.4%) outpatient IB cases were identified over 45 years.
• Constipation (94%) and cranial nerve palsies (94%) were the most common symptoms.
• Cases occurred nationwide, with a median age of 20 weeks at onset.

Conclusions:

• Outpatient IB is likely underrecognized due to mild, non-hospitalization-requiring symptoms.
• Diagnosis requires clinical suspicion and laboratory confirmation.
• Healthcare providers should consider IB in infants with failure to thrive, feeding issues, constipation, or cranial nerve palsies.