Diagnosis of botulism

For botulism to be diagnosed in a patient, the medical history and the results of his physical examination must indicate the presence of the disease. Nevertheless, at times other ailments may have similar symptoms to botulism. These include stroke, myasthenia gravis, and Guillain-Barré syndrome.

Guillain-Barré is a disease produced through vaccinations. It happens when certain fluids taken from animals are injected into the blood stream. Its symptoms are similar to those of botulism. Symptoms start with neurological weakness in the arms, legs and face. As disease progresses, the motor nerves become paralyzed. Collapse of respiratory systems occurs.

Myasthenia gravis is a disorder that is causes weakness in the muscles. Symptoms are droopy eyelids, difficulty in breathing, chewing, talking and swallowing. Symptoms start gradually and worsen during the evenings.

Medical tests such as brain scan, nerve conduction test which is equally referred to as electromyography and abbreviated as EMG, cerebrospinal fluid collection test and edrophonium chloride test can help detect these disorders thus excluding them in the diagnosis for botulism.

Contrarily, diagnosis can be precisely carried out should botulinum toxins be detected in the food, vomit, excreta, stomach or contents of the intestine. An example of is infant botulism diagnosis.  Botulism toxins are rarely found in the blood stream in very severe instances.

Procedures such as enzyme-linked immunosorbent assays (ELISAs), electrochemiluminescent tests (ECL) and feeding trials and vaccinations performed on mice are ways of identifying botulism toxins.  Other means of diagnosis are by tissue culture which signifies growth in an artificial environment of cells that have been taken from living tissue.

An example of one such environment is an egg yolk. The presence of botulinum toxins in the yolk would cause an appearance of milky brightness and display of colours on its surface.

The cerebrospinal fluid collection (CSF) test is one that examines the fluid around the brain and spinal cord (cerebrospinal). The fluid serves as a shield for the brain and spinal cord against injury. The fluid usually appears clear. The purpose of the test is to measure the pressures within the cerebrospinal fluid as well as to take a sample of the fluid for testing. Examination of the fluid sample aids in the diagnosis of some neurologic diseases such as meningitis and damages to the brain and spinal cord.  

A cloudy looking CSF could indicate the presence of an infection or an increase in protein or white blood cells.
An increase in protein could mean the presence of blood, diabetes, tumor, polyneuritis, injury or an infection in the CSF whereas a decrease in protein connotes a swift production of CSF.

Edrophonium chloride belongs to the family of anticholinesterase which is a group of drugs that obstruct the break down of the neurotransmitter acetylcholine by acetylcholinesterase, a collection of enzymes found in the nervous system. The drug is approved for the diagnosis of myasthenia gravis.

ELISAs denotes a blood test that is performed to detect antibodies in the blood. If antibody is present the blood changes into another colour.