All botulisms are due to toxins given off by Clostridium botulinum bacteria that attack the body's nervous system.
Food-borne botulism is caused by eating toxin already formed in contaminated food.
In infant botulism, the baby does not ingest toxin; instead, spores from the botulism bacteria produce toxin in the baby's immature digestive tract. The toxins then travel to the baby's nerve cells leading to the characteristics symptoms of weakness and the "floppy infant syndrome."
Infant botulism is quite different from the botulism caused by eating contaminated foods. Infant botulism occurs in babies younger than six months old, and, if hospital care is provided, is not as serious as food-borne botulism.
Once the toxin is absorbed into circulation, it is carried to and irreversibly blocks the peripheral cholinergic synapses throughout the body, particularly at the neuromuscular junction.
Infant botulism ranges from mild illness to death. Most babies recover with hospital intensive care. If this care is not available, the baby is less likely to survive. Some experts believe that infant botulism causes about five percent of sudden infant death syndrome cases.
Most babies who contract infant botulism are younger than six months old, and all are younger than 12 months old. It occurs in all racial and ethnic groups. Infant botulism has been reported in North and South America.
Infant botulism is a rare disease, and often it is not clear how the baby by got it. The C. botulinum spores can survive for a long time in the environment, such as in vacuum cleaner dust and soil.
About ten percent of commercial honey contains botulism spores, and some cases of infant botulism have been traced to feeding honey to babies. Rarely, light and dark corn syrup may contain spores. Infant botulism is not transmitted from person to person. The role of breastfeeding as a risk factor is poorly understood - infants may be more susceptible during weaning.
Babies with infant botulism are weak and floppy, feed poorly, and cry weakly. Constipation occurs initially in approximately two-thirds of cases. This may be followed by varying degrees of neuromuscular paralysis - the floppy infant syndrome.
Infant botulism is hard to diagnose since it resembles several other disorders. The diagnosis can made by laboratory isolation of C. botulinum and toxin in the stool.
Human-derived botulism immune globulin is the treatment of choice for botulism in infants. The botulism “anti-toxin” attaches itself to the botulism toxin. Once attached to the anti-toxin, the toxin cannot harm the baby and is removed from the blood by the baby’s own natural processes. Although this treatment does not shorten the time the baby experiences the illness, it does appear to reduce the risk the baby will die from the disorder.
Another key component of treatment is support of respiration and nutrition. Usual care consists of IV fluids and nourishment and careful monitoring of the baby's breathing and heart rate. In severe cases, the baby cannot breathe on his/her own and will need assisted mechanical ventilation.
Prospects for eventual complete recovery are excellent, given prompt intervention and good supportive care. Recovery is slow and hospitalizations average about four to six weeks.
It is best not to feed honey to infants.