Charles Patrick Davis, MD, PhD
Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.
Melissa Conrad Stöppler, MD
Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
In this Article
- Botulism facts
- What is botulism?
- What causes botulism?
- How many kinds of botulism are there?
- How serious is botulism?
- How does botulism neurotoxin affect the body?
- What kind of organism is Clostridium botulinum?
- How common is botulism?
- What are botulism symptoms and signs?
- How soon do symptoms appear?
- How is botulism diagnosed?
- How is botulism treated?
- What are complications from botulism?
- What is the prognosis (outcome) of people with botulism?
- Can botulism be prevented?
- Is botulism neurotoxin really considered to be a potential biological weapon?
- Why are botulism neurotoxins used as cosmetic treatments or treatments for some medical conditions?
What are botulism symptoms and signs?
The classic symptoms of botulism include double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, and muscle weakness. Constipation may occur. The doctor's examination may reveal that the gag reflex and the deep tendon reflexes like the knee-jerk reflex are decreased or absent.
Infants with botulism appear lethargic, weak, and floppy, feed poorly, become constipated, and have a weak cry and poor muscle tone. In infants, constipation is often the first symptom to occur.
These are all symptoms of the muscle paralysis that is caused by the bacterial neurotoxin. If untreated, these symptoms may progress to cause paralysis in various parts of the body, often seen as a descending paralysis of the arms, legs, trunk, and breathing muscles.
How soon do symptoms appear?
In food-borne botulism, symptoms generally begin 18-36 hours after eating a contaminated food, but they can occur as early as six hours or as late as 10 days afterward.
How is botulism diagnosed?
The patient's history and physical examination may suggest botulism, but these clues are usually not enough to allow a diagnosis of botulism. Symptoms of other diseases, such as a stroke, Guillain-Barré syndrome (another disease of muscle paralysis), and myasthenia gravis (which also causes weakness and eyelid drooping) can appear similar to those of botulism. Special tests may be needed to exclude these other conditions. These tests may include a brain scan, spinal fluid examination, nerve conduction test (electromyography, or EMG), and a tensilon test for myasthenia gravis. However, if botulism is strongly suspected (for example, several patients with botulism symptoms who ate from the same home-preserved food container), samples should be obtained for a mouse inoculation test (see below) and then the patients should be treated immediately with botulism antiserum. These tests will help distinguish botulism from infections with Salmonella, E. coli</i>, and other Clostridium species (tetanus).
The most direct way to confirm the diagnosis is to identify the botulinum neurotoxin in the patient's blood, serum, or stool. This is done by injecting the patient's serum or stool into the peritoneal cavity of mice. An equal amount of serum or stool from the patient is treated with multivalent antitoxin and injected in other mice. If the antitoxin-treated serum- or stool-injected mice live while those injected with untreated serum or stool die, then this is a positive test for botulism and is called the mouse inoculation test. The bacteria can also be isolated from the stool of people with food-borne and infant botulism, but this is not a definitive test. However, stool cultures can help differentiate botulism from E. coli, Salmonella, and other infectious agents.
Next: How is botulism treated?
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