Most affected infants are under 6 months of age, with onset during the second month after birth common.
The source of the colonizing spores is often unknown. Honey and corn syrup have been implicated in some cases. Other cases have been acquired from soil or dust.
Clinical findings may range from mild to severe:
(1) constipation
(2) poor feeding with failure to thrive
(3) lethargy
(4) weak cry
(5) decreased sucking
(6) generalized decrease in skeletal muscle tone, with weakness in neck muscles causing a "floppy" head
(7) respiratory paralysis with sudden death may occur in severe cases
Laboratory testing:
(1) Serum assay for toxin may be negative.
(2) Stool assay for toxin may be positive.
(3) An anaerobic stool culture for Clostridium botulinum may be positive.
The toxin assay is based demonstrating its effect after injection into mice. Mixing the serum with specific antitoxin antibodies will neutralize the effect.
Diagnosis may be difficult, especially in mild cases. It is necessary to exclude other causes such as viral infections or toxic ingestions.
