Botulism is a rare but serious paralytic illness caused by
a bacterium called Clostridium botulinum. The symptoms are not caused by the
organism itself, but by the toxin that the bacterium releases. The disease is an
intoxication caused by extremely potent toxins preformed in foods.
There are seven recognized types of botulism. Four of these (types A, B, E and
rarely F) cause human botulism. Types C, D and E cause illness in mammals, birds
and fish. The sporulated form of the bacterium is commonly found in soils,
aquatic sediments and fish. The spores are heat-resistant.
Clostridium botulinum is an "anaerobic bacterium", which means it can only grow
in the absence of oxygen. Therefore, the growth of the bacteria and the
formation of toxin tend to occur in products with low oxygen content and the
right combination of storage temperature and preservative parameters.
There are three kinds of botulism characterized differently on the basis of
their means of exposure:
- Foodborne botulism. It comes from eating foods contaminated with the toxin.
- Wound botulism. Caused by a botulism toxin that is produced from a wound that
was contaminated with Clostridium botulinum.
- Infant botulism. It is caused by consuming the spores of the bacteria, which
then release toxins in the intestines.
All forms lead to paralysis that typically starts with the muscles of the face
and then spreads towards the limbs. In severe forms, it leads to paralysis of
the breathing muscles and causes respiratory failure. In view of this
life-threatening complication, all suspected cases of botulism are treated as
The symptoms of food borne botulism usually occur 18 to 36 hours after eating
contaminated food. However, symptoms may occur as early as six hours or as late
as 10 days following exposure.
There is no fever with this infection.
Infants with botulism may seem lethargic, feed poorly, experience constipation,
and have a weak cry and appear floppy.
If left untreated, symptoms may progress to paralysis of the arms, legs, trunk,
and breathing muscles. The symptoms of botulism may resemble other medical
conditions or problems. Recovery from botulism may take many weeks. Fatigue and
shortness of breath may persist for years.