Botulism: Symptoms, Causes, and Treatment
Bacteria have many different mechanisms for producing disease, from invading tissues to producing toxins. Botulism is an infectious disease produced by a bacterial toxin, and today we’ll learn all about its symptoms, causes, and treatments.
The toxin-producing microorganism is a bacterium called Clostridium botulinum. The bacterium is capable of producing 8 different types of toxins, 5 of which are capable of affecting humans. The most frequently isolated toxins in patients are types A, B, and C.
Generally speaking, botulism is a paralyzing disease due to the action of the toxin at a neuromuscular level. The toxin irreversibly blocks the release of a neurotransmitter called acetylcholine in skeletal muscles, preventing them from contracting.
What are the causes of the disease?
As previously mentioned, the main cause of the disease is the botulinum toxin produced by the bacterium C. botulinum. It’s important to note that the bacteria in question are found on multiple surfaces in the form of spores, which are very resistant to changes in temperature and to media with a pH greater than 4.6.
The bacteria have many ways of entering the body, producing the toxin within it, and then causing this condition. The disease has been divided into three different forms which are the following.
This form of the disease affects adults, in most cases, who ingest the preformed toxin in food. The main origin of this disease is usually canned or home-fermented foods such as vegetables, fruit, and fish.
The bacteria in question belong to the group of anaerobes, which are microorganisms that need an environment with little oxygen to reproduce and produce the toxin. In this way, canning without proper precautions and improper food processing provide the ideal environment.
On the other hand, there are cases of people who have contracted food botulism by eating spicy foods, baked potatoes wrapped in aluminum foil, and garlic-infused oils.
This is one of the rarer forms of the disease and occurs when bacteria enter the body through an open wound. On many occasions, the initial injury can go unnoticed, and so the infection becomes evident when there’s systemic involvement.
Any cut can serve as a gateway for the microorganism, which will produce the harmful toxin when it’s inside the body. This type of botulism is more frequent in people who use parenteral drugs, especially in heroin addicts due to the poor sanitary conditions they find themselves in.
In this case, the entry of the bacteria into the human body is very similar to that of alimentary botulism, however, those affected are usually children under 6 months. Studies show that this is the most common form of presentation of all and the intensity of the symptoms will depend on the amount of spores ingested.
Children older than 1 year have a mature intestinal microbiota, which prevents the intestinal reproduction of C. botulinum. However, babies lack this maturation, and so the bacteria can multiply in the digestive tract and produce the toxin that will cause the disease.
The spores of the bacteria can be found in many foods such as vegetables. However, among the most frequent sources are honey and exposure to contaminated soil. Importantly, this form of botulism can affect adults with intestinal abnormalities and will be called intestinal botulism.
Fortunately, the symptoms will be very similar regardless of the type of botulism you have. Generally speaking, patients suffer from progressive, descending, flaccid paralysis. People have difficulty performing muscle contraction and then develop respiratory problems.
The incubation time from when the spores or toxin are ingested can vary between 0 and 12 days. Through multiple studies it has been possible to establish a classic pentad for the disease, although only 13% of patients present all the symptoms, which are the following:
- Dry mouth
- Nausea and vomiting
- Double vision.
- Paralytic mydriasis.
On the other hand, it’s also common for patients with the infection to suffer other symptoms such as respiratory distress, eyelid ptosis, limb weakness, dizziness, constipation, and abdominal pain.
The physical manifestations of botulism can vary in children younger than 6 months as the nervous and gastrointestinal systems aren’t yet fully mature. The incubation time will also vary, so symptoms can start between 18 and 36 hours after ingesting the spores.
In this sense, among the most frequent symptoms that infants have, the following stand out:
- Few movements or lazy movements
- Weak cry
- Difficulty sucking
How is the disease diagnosed?
The diagnosis of botulism is clinical in most cases. The doctor will inquire about the onset of symptoms and the food consumed. In infants, the specialist may ask about the consumption of honey. Multiple studies associate the consumption of this with a significant number of cases of infant botulism.
When it comes to the physical examination, the specialist will check the muscle weakness through different semiological examination techniques. Additionally, you should also focus on checking for droopy eyelids and voice weakness.
Blood and stool tests can be helpful in identifying botulinum toxin, thus confirming the diagnosis. However, the results usually take several days, so the medical examination remains the main diagnostic method.
The main treatment of the disease consists of the early administration of antitoxin. This compound will bind to botulinum toxin, circulating in the bloodstream and prevent it from sticking to nerve endings.
Babies are treated with a specific type of antitoxin called botulinum immunoglobulin, which employs the use of antibodies. It’s important to note that the antitoxin with the ensuring damage caused, however, the nerves regenerate on their own, thus avoiding the sequelae.
The use of antibiotics is only recommended in cases of wound botulism, since they can accelerate the release of toxins in other forms. Lastly, people may need multiple therapies to regain impaired functions such as swallowing and speech.
Botulism prevention is based on good food preparation practices and proper hygiene measures. In this sense, boiling can destroy the vegetative forms of the bacteria and prevent the synthesis of the toxin in food.
The use of salt and the acidic conditions of the medium are also able to prevent bacterial proliferation. The commercial pasteurization process isn’t always sufficient to destroy spores, and so it’s recommended to refrigerate the food and not to keep it at room temperature.
Another great preventive measure is not to give honey to children under 1 year of age, since it can contain a large number of spores and the digestive system of children isn’t capable of destroying them. In general terms, there are some keys to its prevention:
- Maintain proper hygiene
- Separate raw food from cooked food
- Cook food completely
- Store the products to be ingested at safe temperatures
- Use drinking water for cooking
A toxin with some medical applications
Botulism appears as and when the botulinum toxin appears in the body; this is a serious disease that can be fatal. However, this toxin has certain medical applications in the prevention of facial wrinkles, it’s also useful in the treatment of severe headaches and palpebral spasms.
It’s important to remember that it’s a toxic product, and so you should consult your doctor before applying any of these treatments. In the case of infants, parents must be very vigilant before constipation appears, especially if the child has been given honey.
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