Infant botulism is the most common type of botulism, a rare but serious illness caused by toxins produced by specific bacteria. The first sign of the disease is usually constipation. Other symptoms include lethargy, poor feeding, a weak cry, and poor muscle tone. The fatality rate is less than 2 percent, and recovery is usually complete.
What Is Infant Botulism?
Botulism is a rare but serious illness that is caused by toxins (poisons) produced by specific bacteria. In severe cases, it can lead to paralysis or death. Infant botulism is the most common form of the disease (see Botulism Types). About 75 percent of cases that occur each year are infant botulism.
Infant Botulism and Clostridium Botulinum Spores
Infant botulism differs from foodborne botulism in that the toxins themselves are not ingested. Instead, Clostridium botulinum spores are swallowed by the infant. Spores allow bacteria to survive in a dormant state until exposed to conditions that can support their growth. When consumed, these spores turn into bacteria in the favorable environment of the baby's large intestine and produce a toxin responsible for symptoms of the disease.
Because the spores are nearly everywhere in the environment, children and adults regularly ingest them, yet rarely suffer ill effects.
Infant Botulism and the Immature Gut
In a few cases, adults who have had intestinal surgery or whose intestinal tracts have otherwise been altered have contracted the disease the way infants do. This has led researchers to conclude that infants' as-yet incompletely developed intestinal flora may be to blame.
Infants' immature intestinal tracts offer a "window of vulnerability," and if a baby has the bad luck to swallow a botulism spore during that period, the spore has an opportunity to germinate. The spores travel with microscopic dust particles, so researchers have concluded that most affected infants have simply inhaled the spores. They mix with saliva, they are swallowed, and that is how they reach the intestine. Unfortunately, there is no way to prevent infant botulism in such cases.