Botulism: Overview, Symptoms, Causes, Diagnosis and Management

Botulism is a rare but serious medical illness which is caused by a toxin known as botulinum. This toxin is produced by bacteria. This toxin affects the muscle and stop their activity causing paralysis. There are three types of botulism depending upon the way by which the toxin enters into the body. It can be fatal, if the toxin reaches to the respiratory muscles, thus stopping the breathing. Therefore, irrespective of the types, all the cases of botulism are considered as medical emergencies. 

Symptoms

Signs and symptoms of botulism depends upon the type of botulism one is suffering from. There are three types of botulism

Food-borne botulism: food especially home-canned foods which offers a good place for the bacteria to multiply as they are canned without adding propriate preservatives, can contain preformed toxin. Consumption of such toxin containing food can cause food-borne botulism with the following signs and symptoms.

• Nausea, vomiting and abdominal cramps
• Diarrhea followed by constipation
• Difficulty in swallowing or speaking
• Dry mouth
• Weakness starting in the face which might spread to other parts of the body
• Difficulty in breathing
• paralysis

Wound botulism: if the wound is not managed and covered well, then there are chances that bacteria can get into a cut and start producing toxin. The time of appearance of symptoms varies from 4 days to 12 weeks. Since the toxin has entered through a wound, there are no symptoms of digestive system like nausea, vomiting etc. Only neurological symptoms predominate like blurring of vision, facial weakness, drooping eye lids, difficulty in swallowing or breathing and paralysis.

Infant botulism: it occurs mostly in infants below the age of 6 months. The food is culprit here but it’s different from food-borne botulism because the food doesn’t contain preformed toxins. It contains bacterial spores which are taken along with the diet. The toxin is produced by the proliferation of the bacteria in the gut of the infant after taking this food. This situation doesn’t occur in children older than 6 months because of the development of natural defense system of the intestine which is capable of destroying these bacteria. The initial signs and symptoms of infant botulism are

• Constipation
• Loss of appetite
• Weakness
• An altered cry
• A striking loss of head control

Rest of the signs and symptoms are same as that of other botulism.

Causes

Botulism is caused by the botulinum toxin produced by the bacterium Clostridium botulinum. It can survive in the environment in the form of spores. These spores grow in favorable environment to produce toxins and even minimal amount of toxin consumed can prove fatal. The toxin disrupts the coordination between brain and our muscles. The muscles stop contracting producing various signs and symptoms. According to the source of toxin there are several types of botulism

• Food-borne botulism
• Wound botulism
• Infant botulism
• Iatrogenic botulism: botulinum toxin in the form of botox is used to treat facial wrinkles. Overdose of botox can lead to botulism.

Diagnosis

Botulism is a medical emergency, so a clinical diagnosis is enough to start the treatment. The clinical diagnosis is based on the clinical history and examination of the patient. The physician will look for the history of any wound or inappropriate food consumption. Sample of serum, food or stools can be sent in parallel for the laboratory confirmation of toxin. The condition of botulism can often be confused with stroke or myasthenia gravis.

Management

Antitoxin should be given to the patient as soon as botulism is suspected without waiting for the test results. Increase delay in receiving the treatment may increase the fatality rate. Along with this definite treatment, supportive care is also required like in case of wounds, antibiotics can be given. Ventilator can be required in the patients who are having difficulty in the breathing.

Prognosis

Before the discovery of antitoxin about half of the patients of botulism end up dying but nowadays the rate is reduced to around 3 percent. Patients with significant toxin load in the body can require longer in-patient hospitalization stay.

Prevention

Botulism is an easily preventable illness. To reduce the chanced of wound botulism, you should take urgent care of any wound on the body. For the food borne metabolism, it is advisable to practice good food hygiene like

• Follow proper instruction of canning food at home
• Avoid food with any sings of spillage or puffing
• Don’t try to taste old canned food items
• Not to give honey to infants below the age of 12 months.

References

• Botulism [Internet]. Available from: https://www.who.int/news-room/fact-sheets/detail/botulism
• Botulism | Botulism | CDC [Internet]. Available from: \https://www.cdc.gov/botulism/index.html
• Chatham-Stephens K, Fleck-Derderian S, Johnson SD, Sobel J, Rao AK, Meaney-Delman D. Clinical Features of Foodborne and Wound Botulism: A Systematic Review of the Literature,1932-2015. Clin Infect Dis. 2017 27;66(suppl_1):S11–6.
• Gottlieb SL, Kretsinger K, Tarkhashvili N, Chakvetadze N, Chokheli M, Chubinidze M, et al. Long-term outcomes of 217 botulism cases in the Republic of Georgia. Clin Infect Dis. 2007 Jul 15;45(2):174–80.