Botulism

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Botulism is a bacterial disease which can affect both vertebrates and invertebrates; humans, birds, rats, mice, chickens, frogs, fishes, drosophila, leeches and toads, but it is uncommon in domestic animals. Botulism is a neurologic disorder that could result in life-threatening neuro paralysis due to a neurotoxin produced by a bacteria called Clostridium botulinum. C botulinum is a gram-positive bacteria distributed widely in soil and found worldwide. The toxin binds to membranes of peripheral neuromuscular and autonomic nerve junctions which blocks the release of acetylcholine. This block of neuromuscular transmission in nerve fibers leads to weakness, paralysis and respiratory arrest. So it largely affects nervous system, but also gastrointestinal, endocrine, and metabolic systems as well.

There are three types of botulism, which are infant botulism (IB), foodborne botulism (FBB), and wound botulism (WB). Infant botulism is caused by C botulinum spores which could be picked up from bee honey or environment, these spores germinate in the small intestine during early stages of their lives. Next, the bacterium produces the toxin, which is absorbed into the bloodstream. Botulism is a rare bacterial poisoning, but can be fatal. Usually infants would completely recover following the right treatment; and the mortality rate for IB is less than 1%. Foodborne botulism is a result of improperly canned food; this happens because spores are likely to germinate in low-oxygen conditions. FBB has a mortality rate of 5-10%. Wound botulism is a result of contamination of wound with C botulinum, which then secrete the toxin into the bloodstream. WB became more common in people who use intravenous drugs (catheters), and it has a mortality rate of 15-17%. Both FBB and WB are more common in adults.

More than 90% of individuals who have this disease experience at least 3-5 of the following symptoms: nausea, vomiting, difficulty speaking and swallowing, dilated pupils, weak eye muscle, slow reflexes and extremely dry throat. Symptoms would usually show up within 12-36 hours after consuming contaminated food, but sometimes it can take a few days. Botulism is diagnosed using a mouse neutralization bioassay by isolating the botulinum toxin. Botulism requires emergency medical care, breathing assistance and antitoxin injection. Prevention of disease could be achieved by heating it more than 85 Celsius for longer than 5 minutes, and also by proper food preparation, and by not giving honey to children less than one years old.

Sources

http://emedicine.medscape.com/article/213311-overview#a1

http://www.who.int/mediacentre/factsheets/fs270/en/

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