Information for Health Professionals

Clinical Features

Botulism Case Consultation

If you suspect your patient may have botulism, call your state public health departmentexternal icon immediately. If there is no answer, contact CDC 24/7 at 770-488-7100.

  • For non-infant cases: State public health officials can reach the CDC clinical emergency botulism service for consultation and antitoxin 24/7 at 770-488-7100.
  • For infant botulism: The Infant Botulism Treatment and Prevention Programexternal icon(IBTPP) at the California Department of Public Health provides consultation 24/7 and can be reached at 510-231-7600.

If clinical consultation supports botulism, request antitoxin immediately and begin treatment as soon as it is available. Do not wait for laboratory confirmation. If administered early in the course of illness, antitoxin can prevent progression of illness and shorten its duration.

Is your patient an infant?

See step-by-step guidance for clinicians of patients who may have infant botulism.

Take a look >

Botulism is a neuroparalytic illness characterized by symmetric, descending flaccid paralysis of motor and autonomic nerves, always beginning with the cranial nerves.

Signs and symptoms may include:

  • Dysphagia
  • Muscle weakness
  • Diplopia
  • Ptosis
  • Blurry vision
  • Slurred speech
  • Respiratory distress or failure
  • Ocular palsy

Possible signs and symptoms in foodborne botulism may also include:

  • Vomiting
  • Nausea
  • Abdominal pain
  • Diarrhea

Signs and symptoms in an infant may include:

  • Constipation
  • Poor feeding
  • Ptosis
  • Sluggish pupils
  • Flattened facial expression
  • Diminished suck and gag reflexes
  • Weak and altered cry
  • Respiratory distress or failure

If untreated, illness from any type of botulism can progress to descending paralysis of respiratory muscles, arms, and legs.


Initial diagnosis is based on clinical symptoms. Do not wait for laboratory confirmation to begin treatment.

Botulism differs from other flaccid paralyses in that it typically manifests initially with prominent cranial nerve palsies. It also differs in its invariable descending progression, in its symmetry, and in its absence of sensory nerve dysfunction.

Botulism is frequently misdiagnosed, most often as a polyradiculoneuropathy (Guillain-Barré or Miller-Fisher syndrome), myasthenia gravis, or other diseases of the central nervous system.

Differential Diagnoses

  • Bacterial or chemical food poisoning
  • Cerebrovascular accident (CVA)
  • Chemical intoxication
    (e.g., carbon monoxide, opioid intoxication)
  • Congenital myopathy
  • Electrolyte-mineral imbalance
  • Guillain-Barré syndrome
  • Lambert-Eaton myasthenic syndrome
  • Leigh syndrome
  • Meningitis
  • Miller-Fisher syndrome
  • Mushroom poisoning
  • Myasthenia gravis
  • Poliomyelitis
  • Reye’s syndrome
  • Sepsis
  • Tick paralysis
  • Werdnig-Hoffman disease
  • West Nile Virus

Routine laboratory test results are usually unremarkable for people with botulism. A normal Tensilon test helps to differentiate botulism from myasthenia gravis; borderline positive tests can occur in botulism. A normal CT or MRI helps to rule out cerebrovascular accident.


If consultation supports botulism, request treatment and administer it as soon as possible. Botulism Antitoxin Heptavalentexternal icon and BabyBIGexternal icon do not reverse paralysis but arrest its progression. Recovery follows the regeneration of new neuromuscular connections.

Exercise meticulous intensive care, including monitoring of respiratory function and, when required, mechanical ventilation. In more severe cases, ventilator support may be required for weeks to months.

Treatment for wound botulism may also include wound debridement to remove the source of toxin‑producing bacteria and antibiotic therapy.

Diagnostic Testing

Laboratory confirmation is done by demonstrating the presence of botulinum toxin in serum, stool, or food, or by culturing botulinum neurotoxin-producing species of Clostridium (C. botulinumC. butyricum, or C. baratii) from stool or a wound.

Diagnostic testing is done through the state public health department’s laboratory. CDC provides testing services for some state public health departments.

This specialized testing often takes days to complete. Follow up with your state health department if you do not receive results within 5 days.

See information on submitting a specimen to CDC >

Notification and Reporting

Botulism is a notifiable disease in the United States. Physicians must promptly notify the state health department of suspected cases, and laboratories must notify the state health department of all confirmed cases.

State health departments report confirmed cases to CDC through the National Notifiable Diseases Surveillance System.

Etiology and Transmission

Botulism is caused by a potent neurotoxin produced by Clostridium botulinum and rare strains of C. butyricum and C. baratii, all of which are anaerobic, spore-forming bacteria.

The five main types of botulism are infant, foodborne, wound, adult intestinal colonization, and iatrogenic. Transmission differs by type. Learn more >


Death can result from respiratory failure or the consequences of extended paralysis. About 5% of patients die. Recovery takes weeks to months. Those who survive may have fatigue and shortness of breath for years.


For surveillance purposes, CDC categorizes human botulism cases into four transmission categories: infant botulism, foodborne botulism, wound botulism, and “other” botulism, which includes adult intestinal colonization, iatrogenic botulism, and unknown routes of transmission.

In 2017, a total of 182 cases of laboratory-confirmed botulism were reported to CDC. Of these, 141 were infant, 19 were foodborne, 19 were wound botulism and 3 were “other,” classified as 2 iatrogenic, and 1 suspected adult intestinal colonization.

The National Botulism Surveillance System collects reports of all laboratory-confirmed botulism cases in the United States and is continuously monitored for early detection of outbreaks. Read CDC’s annual summaries of botulism cases reported in the United States from 2001 through the most recent year of confirmed data.