Botulism is an acute neurologic disorder manifested by life-threatening paralysis due to a neurotoxin produced by Clostridium botulinum or related species (C baratii and C butyricum). Exposure may occur via 4 routes[1, 2] :
Botulism generally progresses as follows:
The autonomic nervous system is also involved in botulism (typically in cases caused by toxin type B), with manifestations that include the following[23] :
Other neurologic findings include the following[2, 4] :
Ophthalmic manifestations may reflect the anticholinergic effects of the neurotoxins.
Ocular manifestations may be the manifesting features of botulism. However, their absence does not exclude this disease, since the 8 different toxins appear to involve the ocular system to various degrees.
As reported by physicians caring for 332 different botulism patients [5] :
The diagnosis initially must be made clinically, as waiting for laboratory confirmation would harmfully delay therapy.[6]
The standard for laboratory diagnosis is a mouse neutralization bioassay confirming botulism by isolation of the toxin. Toxin may be identified in the following:
Clostridium botulinum may be grown on selective media from samples of stool or foods. Note that the specimens for toxin analysis should be refrigerated, but culture samples of C botulinum should not be refrigerated. Wound cultures that grow C botulinum suggest the presence of wound botulism.
Electromyography [7, 8]
Characteristic electromyographic findings in patients with botulism include the following:
An incremental increase in M-wave amplitude with rapid repetitive nerve stimulation may help to localize the disorder to the neuromuscular junction.
See Workup for more detail.
Rigorous supportive care, including use of the following, is essential in patients with botulism:
Magnesium salts, citrate, and sulfate should not be administered, because magnesium can potentiate the toxin-induced neuromuscular blockade.
Wound botulism requires the following:
Measures to reduce the risk of nosocomial infections include the following:
Careful attention to peripheral and central intravenous catheters with regular site rotation to reduce the risks of thrombophlebitis, cellulitis, and line infections should be part of the patient’s supportive care.
See Treatment and Medication for more detail.
Botulism is a critical neurologic syndrome characterized by acute neuroparalytic manifestations resulting from a neurotoxin secreted by Clostridium botulinum.[2, 9] The toxin binds irreversibly to the presynaptic membranes of peripheral neuromuscular and autonomic nerve junctions. Toxin binding blocks acetylcholine release, resulting in weakness, flaccid paralysis, and, often, respiratory arrest. Cure occurs following sprouting of new nerve terminals.
The 3 main clinical presentations of botulism include infant botulism or intestinal botulism,[10] foodborne botulism, and wound botulism. Iatrogenic botulism also may ccur via cosmetic or therapeutic injection of any commercially made botulinum toxin (eg, Botox, Dysport, Xeomin, Myobloc).[2] Additionally, because of the potency of the toxin and ease of aerosolization, the possibility of inhalational botulism as a bioterrorism agent or biological weapon is of great concern.[2, 11] For more information, see CBRNE – Botulism.
Clostridium botulinum produces 8 distinct neurotoxins, including types A through G and the potent F/A Hybrid.[2] Among these, types A, B, E, and occasionally F and F/A Hybrid (previously known as H) can impact human health. These botulinum toxins are highly toxic proteins that can withstand degradation from stomach acid and proteolytic enzymes. Type F/A Hybrid is considered the most potent toxin among them. In the United States, around 50% of foodborne outbreaks are attributed to type A toxin, followed by types B and E. Geographically, type A toxin is more prevalent in areas west of the Mississippi River, type B is common in eastern states, and type E often is associated with regions such as Alaska and the Great Lakes area where ingestion of fish and fish products is frequent.
The mechanism of action involves toxin-mediated blockade of neuromuscular transmission in cholinergic nerve fibers.[12] This is accomplished by inhibiting acetylcholine release at the presynaptic clefts of the myoneural junctions. Toxins are absorbed from the stomach and small intestine, where they remain stable despite digestive enzymes. Subsequently, they are hematogenously disseminated to peripheral cholinergic nerve terminals (neuromuscular junctions, postganglionic parasympathetic nerve terminals, peripheral ganglia). The toxin is endocytosed by the neuron and then is allowed to cleave proteins essential for neurotransmitter release. The toxin does not cross the blood-brain barrier, likely secondary to its large size, however, it may be transported to the central nervous system axonally.[13]
Because the motor end plate responds to acetylcholine, botulinum toxin ingestion results in hypotonia that manifests as descending symmetric flaccid paralysis and is usually associated with gastrointestinal symptoms of nausea, vomiting, and diarrhea. Cranial nerves are affected early in the disease course. Later complications include paralytic ileus, severe constipation, and urinary retention.
Humans commonly ingest C botulinum spores, but germination typically does not occur in the adult intestine since special conditions are required (ie, anaerobic environment, low acidity, specific amino acid, salt and sugar concentrations, and temperatures 37°F-99°F).[1, 14]
Wound botulism results when wounds are contaminated with C botulinum spores.[2] Wound botulism has developed rarely after cesarean delivery, following traumatic injury that involved soil contamination, and more commonly among injection drug users (particularly those who use black-tar heroin).[15, 16] The wound may appear deceptively benign. Traumatized and devitalized tissue provides an anaerobic medium for the spores to germinate into vegetative organisms and to produce neurotoxin, which then disseminates hematogenously. Symptoms develop after an incubation period of 4-13 days, with a median 6.5 days.[17] The clinical symptoms of wound botulism are similar to those of foodborne botulism except that gastrointestinal symptoms (including nausea, vomiting, diarrhea) are uncommon.
In the United States over hundreds of cases of botulism are reported annually to the Centers for Disease Control and Prevention (CDC).[18] The latest available US surveillance summaries are from 2019. The European CDC has reported that although the annual botulism occurrence in Europe is fewer than 1 per 1,000,000 individuals, children younger than 12 months have the highest risk.[19]
Notably, based on open-source epidemic intelligence, the frequency of reported botulism cases in Ukraine has increased dramatically since the February 2022 invasion by Russia; within months of the invasion, case reporting increased by almost 400%, however, at this point the case-numbers likely are underestimated given the weakening / absence of formal reporting systems.[20] Prior to the analysis of the increase in Ukrainian cases, Romania had reported the highest number of cases in Eastern Europe in 2014 with 31 cases.[21]
The increasing instances of C botulinum in Vietnam have raised alarm among healthcare authorities and policymakers due to the inadequate availability of BAT antitoxin.[22]
For 2019, the CDC reported 152 cases of infant botulism, all of which were laboratory-confirmed, with the highest case-counts coming from California and Pennsylvania.[18]
Infant botulism with mean age of 13 weeks accounts for 60-70% of all botulism cases.[23, 24]
For 2019, the US CDC reported 21 cases of foodborne botulism. Outbreak-related cases are shown below:
For 2019, the US CDC reported 41 cases of wound botulism; the highest number of cases were overwhelmingly reported by California.
Mortality rates vary based on the age of the patient and the type of botulism and have significantly declined since the early 1900s due to improvements in supportive care.
The risk for death due to infant botulism usually is less than 1%.[23]
The modern mortality for foodborne botulism is 5% or less.[1, 27]
Wound botulism carries a mortality rate of roughly 10%.[28]
Clostridium botulinum is an anaerobic, gram-positive bacterium that survives adverse conditions by forming spores and is commonly found in soil and marine sediments.[1, 2] Under anaerobic conditions, these spores can germinate, leading to the production of a highly potent botulinum toxin, which is the most potent toxin known on a molecular weight basis.[2]
Infant botulism is by ingested C botulinum spores that germinate in the infant's intestine.[2] Sources include environmental spores from soil, dust, or contaminated food products such as honey and corn syrup.[23] Despite the association with honey, most cases occur without known exposure to it.
Clinical management primarily involves supportive care, with an infant mortality rate of less than 1%.[14]
Foodborne botulism typically results from ingestion of toxin in improperly canned or home-prepared food.[2] Sources include environmental spores from soil, dust, or contaminated food products like honey and corn syrup.[23]
Despite the association with honey, most cases occur without known exposure to it. Honey, due to its low water activity (0.5 - 0.65), does not support the germination of C. botulinum spores, which require a water activity over 0.94.[29]
Occurs predominantly in adults and can be associated with intravenous drug use, as demonstrated by a case involving a 40-year-old patient who injected black tar heroin and developed botulism, requiring intensive care and antitoxin administration.[30]
C botulinum spores are detected in approximately 20% of soil samples worldwide, with specific toxins associated with different regions.[29, 31]
Toxin A is found predominantly west of the Mississippi River in cases of wound botulism.
Toxin B is most common in the eastern United States, associated with infant botulism.
Toxin E is linked to northern latitudes and frequently associated with fish products[32, 33] .
Toxins C and D are frequent causes of botulism in animals, particularly affecting birds and carnivores. Vultures exhibit high resistance to these toxins, whereas waterfowl are vulnerable due to their feeding habits.[31]
A comprehensive analysis of 6,932 botulism cases from 59 nations revealed a global case fatality rate of 1.37%, with significant underreporting estimated at 88.71% in 2016.[34]
The study emphasized the need for improved awareness among healthcare professionals, better global reporting mechanisms, and enhanced surveillance to reduce the incidence and improve outcomes of botulism cases worldwide.
Wound botulism is more common in females.[24] Foodborne botulism has no sexual predilection.
Foodborne botulism and wound botulism predominately occur in adults. The mean age of infant botulism is 3 months.[23] The vulnerability of infants at the 3-5 month age is thought to be secondary to the change in bacterial taxa while transitioning to foods other than breast milk.[29] From 1976 to 1983, California found a greater percentage of botulism patients who were breastfed versus age-matched controls; however, this discrepancy is attributed to the theory that breastfeeding delays the colonization of the infant microbiome with C botulinum and slows the development of life-threatening toxemia enough so that cases may be diagnosed in the hospital, rather than an infant death occurring at home and being attributed to sudden infant death syndrome (which is twice as likely to occur with formula-fed infants).[29, 35]
Prompt and vigorous supportive care, especially respiratory care, greatly improves the prognosis.
The recovery period from botulism flaccid paralysis takes weeks to months.[2] Death that occurs early in the course of disease is usually secondary to acute respiratory failure, whereas death later in the course of illness is typically secondary to complications associated with prolonged intensive care (ie, venous thromboembolism or hospital-acquired infection). Some patients demonstrate residual weakness or autonomic dysfunction for 1 year after the onset of the illness. However, most patients achieve full neurologic recovery. Permanent deficits may occur in those who sustain significant hypoxic insults.
Following the onset of symptoms, botulism quickly progresses over several days. The magnitude of the neuromuscular impairment can advance hourly. Persons who survive this phase eventually stabilize and then recover over a period of days to months. The mechanism of recovery is not fully understood but requires the generation of new presynaptic axons and the formation of new synapses, as the original synapses are permanently affected. As with tetanus, recovery from botulism does not confer long-term immunity. Rare reports have described a second episode in the same patient.
Symptoms of foodborne botulism typically begin with gastrointestinal issues, appearing 18 to 36 hours after ingestion of contaminated food, though they can start as early as 2 hours or as late as 8 days. Initial symptoms include nausea, vomiting, and diarrhea, often followed by constipation. Many patients also report experiencing a dry mouth.
As the illness progresses, patients may develop acute neurologic symptoms about a day after consuming the contaminated food. The severity of foodborne botulism can vary from mild to severe. If the condition worsens, death can occur, typically around 3 days after hospital admission. The modern mortality rate for this condition is 5% or less, indicating improved outcomes due to advances in medical care.[1, 3, 36]
The incubation period for infant botulism is 2-4 weeks. The peak age of incidence is 2-4 months.
Constipation is the usual presenting symptom, often preceding motor function symptoms by several days or weeks.
Other signs of autonomic dysfunction usually present early as well, including those mentioned above. Gag reflexes frequently are impaired, which can lead to aspiration if the airway is unprotected.
Patients with wound botulism typically have a history of traumatic injury with wounds that are contaminated with soil.[37]
Since 1994, the number of patients with wound botulism who have a history of chronic intravenous drug abuse has increased dramatically. In most cases, black-tar heroin has been the implicated vehicle. Researchers followed 17 heroin users who had recurrent botulism after using black-tar heroin.[15] Physicians need to be alert to recognize botulism, especially in patients who use black-tar heroin or in those with a history of injection drug–associated botulism.
Rare cases of wound botulism after cesarean delivery have been documented.[16]
Aside from a longer incubation period, wound botulism is similar to foodborne botulism. The incubation period of wound botulism ranges from 4-13 days, with a median 6.5 days.[17] Unlike foodborne botulism, gastrointestinal symptoms (including nausea, vomiting, diarrhea) are uncommon in wound botulism. Patients may be febrile, but this more likely is due to the wound infection rather than the wound botulism. In many cases, the wound appears benign.
Adult intestinal toxemia results from enteric colonization with C botulinum that progresses to toxin production. The pathophysiology of the changes in the gastrointestinal flora that facilitate colonization is unclear.[38]
Cases of botulism due to Botox overdosage have been reported.[2] Symptoms vary and can include dysphagia, ptosis, and diplopia, as well as more severe presentations of systemic weakness or muscle paralysis.[39]
A 46-year-old woman presented with respiratory difficulties, weakness, dysphagia, and gait issues a week after self-injecting 100 units of BoNT-A for cosmetic purposes.[40] Despite developing ptosis and neck weakness, she largely retained normal limb function and cognitive abilities. Diagnosed with systemic botulism, she received pyridostigmine treatment, showed improvement, and was transferred to a community hospital after nine days. Although she had residual mild dysphagia, her overall progress was positive, and she was discharged after a month with a full recovery in the following 2 months. The case underscores the rare yet severe effects of illicit BoNT-A injections and stresses the importance of careful administration to prevent such systemic botulism complications.
Almost all patients with foodborne or intestinal exposure are afebrile and the majority of patients will display descending paralysis with cranial nerve palsies early in the disease process. A collection of anticholinergic toxicity symptoms will present such as nausea, vomiting, and the 4 D's, dysphagia, diplopia, dysarthria, and dry mouth.[11, 21] Mydriasis is seen in 50% of cases.
Generally, botulism progresses as follows:
The autonomic nervous system also is involved. Manifestations of this include the following:
Other neurologic findings include the following:
Infant botulism arises when C. botulinum spores, ingested from environmental sources such as soil, dust, or contaminated food products like honey and corn syrup, germinate in an infant's intestine.[2, 23] Although honey is often linked to this condition, the majority of cases are reported without any known exposure to honey.[14]
Of the roughly 110 cases of botulism that occur in the US annually, foodborne exposure accounts for ~25% of cases.[24] It results from the ingestion of preformed neurotoxins; A, B, and E are the most common. California, Washington, Colorado, Oregon and Alaska, have accounted for >50% of reported foodborne outbreaks in the US since 1950.
High-risk foods include home-canned or home-processed low-acid fruits, vegetables, fish and fish products (neurotoxin serotype E).[33]
Commercially processed foods and improperly handled fresh foods are occasionally associated with botulism outbreaks. The type of food responsible for approximately 28% of outbreaks remains unknown.[2]
Wound botulism results when wounds are contaminated with C botulinum spores. Wound botulism has developed rarely after cesaerean delivery, following traumatic injury that involved soil contamination, and more commonly among injection drug users (particularly those who use black-tar heroin).[15, 16, 30] Wound botulism illness can occur even after antibiotics are administered to prevent wound infection. Wound botulism from black-tar heroin use has primarily occurred in California.[24]
High clinical suspicion and clinical diagnosis with immediate antitoxin administration is the cornerstone of management, as laboratory tests are not helpful in the routine diagnosis of botulism; however, they are of help in identifying outbreaks and bioterrorism.[6, 42]
A clinical criteria tool for early diagnosis has been developed for outbreak settings.[43]
When botulism is suspected, consult public health officials immediately, request antitoxin, and if transferring to a higher level of care consider administering antitoxin before transfer.[44] Full neurologic exam, brain imaging, lumbar puncture, electromyography, nerve conduction studies, and monitoring for anaphylaxis after antitoxin administration should be performed as applicable.
WBC counts and erythrocyte sedimentation rates usually are normal.[45] Cerebrospinal fluid is also normal, except for occasional mild elevations in protein concentration.
Collect specimens early for laboratory confirmation as toxin levels decrease over time, and store and transport them at refrigeration temperatures (36°F–46°F).[46]
Conduct frequent, serial neurologic examinations focusing on cranial nerve function, swallowing ability, respiratory status, and extremity strength.
Infants with botulism often experience severe constipation, necessitating an enema to collect stool samples for testing spores and toxins.[47] The CDC advises using sterile nonbacteriostatic water for the enema to avoid interference with lab tests.[48] Stool samples should be stored in a leak-proof container, refrigerated, and sent to the laboratory promptly. Ideally, samples should be collected before beginning treatment with immune globulin, although treatment should not be delayed for test results.
Treatment with immune globulin should commence immediately based on clinical suspicion, as delays can increase the risk of mortality and morbidity. Although PCR testing for spores can provide quick results and has been successful, it is not widely available, and its sensitivity levels are not fully established. For testing guidance, contact local or state public health departments.[47, 49, 50]
A lumbar puncture can help rule out Guillain-Barré syndrome, which typically shows elevated protein levels in the cerebrospinal fluid, and can also exclude meningitis or encephalitis, as botulism does not increase white blood cells in the CSF.
Laboratory confirmation of botulism requires either botulinum neurotoxin isolation or growth of a botulinum neurotoxin-producing Clostridium species (ie, C botulinum, C baratii, or C butyricum) in a stool, gastric aspirate, food, or wound culture.
Botulinum neurotoxin isolation requires intraperitoneal injection of the patient's serum, fluid extract of food or feces, etc. into pairs of mice with and without monovalent antitoxin followed by observation for development of clinical botulism.[6, 51] This test was standardized in the 1970s and has limited sensitivity depending on the mode of toxin exposure. These assays are limited to specific state public health and CDC laboratories, where other assays may also be used to determine neurotoxin serotype. Patient samples must be collected prior to administration of antitoxin, but antitoxin administration must not be delayed in order to obtain samples (serum 5-15 mL, stool 10-20 g, gastric aspirate 5-10 mL, suspected food source 10-20 g or mL).[1]
As the "gold-standard" assay has historically been the ethically controversial mouse bioassay, which requires the use of laboratory animals and personnel trained to recognize signs of botulism in mouse over the course of 4 days, a faster and less resource-intensive technology has been produced with assistance from the US CDC for use in public health labs: the BoNT Endopep-MS method utilizes mass-spectrometry to detect toxins A, B, E, and F and only requires an 8-hour period. The use of this tool has not yet been added to the Botulism management guidelines as of August, 2024.[42]
To send a specimen to the CDC for testing[1] :
C botulinum may be grown on selective media from samples of stool or foods. Note that the specimens for toxin analysis should be refrigerated (not frozen), but culture samples of C botulinum should not be refrigerated. Final results from culture for Clostridium species may take 2-3 weeks.
Because intestinal carriage is rare (and adult intestines typically do not allow for germination), identifying the organism or its toxin in vomitus, gastric fluid, or stool strongly suggests the diagnosis.[2] Isolation of the organism from food without toxin is insufficient grounds for the diagnosis. Only experienced personnel who have been immunized with botulinum toxoid should handle the specimens. Because the toxin may enter the blood stream through the eye or via small breaks in the skin, precaution is warranted.
Wound cultures that grow C botulinum suggest wound botulism.
Imaging studies are generally not useful in the diagnosis of botulism.[52]
The only potential role for imaging studies (eg, CT scan, MRI) would be to rule out CNS pathology, such as intracranial mass lesions, cerebrovascular disease of the brainstem, or basilar artery stroke, in patients in whom the presentation is atypical or vague.[53]
Results from nerve conduction studies are normal, and electromyography (EMG) reveals reduced amplitude of compound muscle action potentials.[7, 8]
EMG may be useful in establishing a diagnosis of botulism, but the findings can be nonspecific and nondiagnostic, even in severe cases. Characteristic findings in patients with botulism include brief low-voltage compound motor-units, small M-wave amplitudes, and overly abundant action potentials. An incremental increase in M-wave amplitude with rapid repetitive nerve stimulation may help to localize the disorder to the neuromuscular junction. Single-fiber EMG may be a more useful and sensitive method for the rapid diagnosis of botulism intoxication, particularly in the absence of signs of general muscular weakness.
The results of the edrophonium chloride, or Tensilon, test for myasthenia gravis may be falsely positive in patients with botulism.[43] If positive, it is typically much less dramatically positive than in patients with myasthenia gravis.
It is essential to administer botulinum antitoxin promptly based on clinical findings without waiting for laboratory confirmation, as administering the treatment within the first 2 days of symptom onset offers the most significant benefit.[1] Healthcare providers also should consider the possibility of botulism in pregnant patients and treat them with the same urgency and protocols as nonpregnant patients. Additionally, it is crucial to provide comprehensive support that addresses both the physical and psychological impacts of the illness on patients and their families. Finally, proactive planning for potential antitoxin shortages is necessary, ensuring that effective systems are in place to manage such crises efficiently.
On March 22, 2013, the FDA approved the first botulism antitoxin that can neutralize all 7 known botulinum nerve toxin serotypes.[54] The heptavalent antitoxin is derived from horse plasma and is the only drug available for treating botulism in patients older than 1 year, including adults. It also is the only available drug for treating infant botulism that is not caused by nerve toxin type A or B; otherwise, human-origin anti-A, anti-B botulinum antitoxin (BabyBIG) should be obtained from the California Infant Botulism Treatment and Prevention Program at +1 510-231-7600 (do not use equine antitoxin for infants).[55]
Older literature on anti-ABE trivalent antitoxin does suggest that it reduces mortality (Odds Ratio [OR], 0.22) most significantly against botulism types E (OR, 0.13) and A (OR, 0.57).[1, 56]
BAT® [Botulism Antitoxin Heptavalent (A, B, C, D, E, F, G) - (Equine)].[1, 57]
Botulism Antitoxin Heptavalent (A, B, C, D, E, F, G) - (Equine) ideally should be administered within 24 hours of symptom onset as the antitoxin cannot reverse existing paralysis, only toxin circulating in the blood. The greatest benefit is seen among those who receive it within 2 days of illness onset. However, regardless of time after disease onset, patients should still receive antitoxin to protect unaffected synapes from persistent circulating toxin, which is known to persist for weeks in the blood.[58]
Consult local or state health department immediately and the 24-hour CDC botulism service to request antitoxin (+1 404-639-2206 or +1 770-488-7100) (https://www.cdc.gov/botulism/health-professional.html)
The standard adult dose for patients >55 kg is one vial (10-22 mL per vial) diluted 1:10 in normal saline by slow intravenous infusion (0.5-2 mL/min)
Adverse effect frequencies (all recently observed adverse effects are nonserious)[59] include the following:
As the half-lives of the antitoxin range from 7.5-34 hours, it is plausible that exposure to a high concentration of toxin may require a second dose of BAT. If disease progression worsens after the first dose should have taken effect and suspicion remains high (ie, known outbreak setting or exposure history), a second dose can be provided within 2 weeks (to avoid developing hypersensitivity reaction to the antitoxin).[1] However, toxin exposure of this magnitude would be a rare occurrence and other diagnoses should be considered in this case.
Pregnant patients with suspected botulism should be treated with BAT just as nonpregnant patients,
See the BAT® package insert here. (https://www.fda.gov/media/85514/download)
In 2021, a 4-month-old infant in China underwent successful fecal microbiota transplantation (FMT) after severe infant botulism persisted despite initial antitoxin therapy.[10] Post-FMT, the infant's gut microbiota composition and fecal metabolites were analyzed, revealing increased diversity in the gut microbiota and significant alterations in fecal metabolites associated with metabolic pathways and anti-inflammatory capabilities.
The study highlighted the potential of FMT in resolving persistent excretion of botulinum toxin in infant botulism cases and indicated the need for further research to better understand the effectiveness and mechanisms of FMT as a treatment modality for this condition.
Antibiotics have no role in the treatment of foodborne or intestinal botulism. Wound botulism may require surgical debridement and antibiotic therapy because of wound infection (Clostridium may be targeted with penicillin or metronidazole). Of note, aminoglycosides should be avoided in patients with botulism as they may aggravate disease through inhibition of presynaptic calcium uptake, which is required for acetylcholine release.[9, 60]
Patients with botulism-induced flaccid paralysis typically do not experience impairment in sensory or cognitive functions directly from the toxin's effects.[1, 2] Therefore, a focused approach to managing paralysis while ensuring overall health is crucial. Supportive care in botulism management involves extensive interventions to address paralysis and related complications, emphasizing the maintenance of vital functions and the prevention of deterioration.
Proper airway management is paramount in botulism cases due to the elevated risk for respiratory failure. Close monitoring and prompt intervention are essential to ensure adequate oxygenation. Hospitalization generally is recommended for patients with symptoms or toxin exposure to allow continuous observation and timely interventions if needed.
Regular assessment of respiratory parameters such as spirometry, pulse oximetry, and arterial blood gases aids in monitoring the respiratory status and guiding treatment decisions. Respiratory failure can progress rapidly; early recognition and intervention, including intubation and mechanical ventilation, are crucial.
Comprehensive management of complications such as bowel dysfunction, urinary retention, and nosocomial infections, requires a holistic approach tailored to the diverse needs of botulism patients. Strategies to prevent complications, including proper skin care, catheter maintenance, and thrombosis prophylaxis, are vital components of care aimed at enhancing patient outcomes and minimizing risks during treatment.
Transfer the patient to an institution able to provide antitoxin and adequate supportive care, if necessary.
Promptly initiate ventilatory support, because respiratory muscle weakness rapidly progresses and the gag reflex frequently is impaired, which predisposes patients to respiratory failure and/or aspiration. Patients need continued suctioning and may require intubation or tracheostomy.
Wound botulism requires incision and thorough debridement of the infected wound, antitoxin therapy, and antibiotics should be provided as clinically indicated.[2]
Consultations with an infectious diseases specialist and a neurologist frequently are beneficial.
A nutritionist should be consulted for hyperalimentation and tube-feeding recommendations and monitoring.
Physical and occupational therapists are needed to work on range-of-motion exercises and assisted ambulation, as tolerated.
A psychiatrist and/or a psychologist is recommended for counseling, as needed; patients with prolonged hospitalization, slow recovery, and complications from the disease or from extended hospitalization are at increased risk for depression.
Pastoral care is recommended, as needed.
Physical medicine and rehabilitation specialists may be helpful in coordinating long-term rehabilitation planning once sustained recovery has begun.
Nasogastric suction and intravenous hyperalimentation are important when an ileus is present. If no ileus is present or when the ileus resolves, tube feeding can be used for nutritional supplementation.
Oral intake should be reinstituted gradually under the following conditions:
The following organization has released guidelines for the management of botulism. Key diagnostic and management recommendations have been reviewed and integrated throughout the article.
Antibiotics are useful in wound botulism, but they have no role in foodborne botulism.
Clinical Context: Preferred drug of choice for wound botulism. Interferes with synthesis of cell wall mucopeptide during active multiplication, resulting in bactericidal activity against susceptible microorganisms.
When botulism develops following a wound infection, antibiotic therapy and meticulous debridement of the wound are essential.
Clinical Context:
Clinical Context: Antitoxin indicated for naturally occurring noninfant botulism. Equine-derived antitoxin that elicits passive antibody (ie, immediate immunity) against Clostridium botulinum toxins A, B, C, D, E, F, and G.
Each 20-mL vial contains equine-derived antibody to the 7 known botulinum toxin types (A through G) with the following nominal potency values: 7500 U anti-A, 5500 U anti-B, 5000 U anti-C, 1000 U anti-D, 8500 U anti-E, 5000 U anti-F, and 1000 U anti-G.
Replaces licensed bivalent botulinum antitoxin AB (BAT-AB) and investigational monovalent botulinum antitoxin E (BAT-E). To obtain, contact CDC Emergency Operations Center; telephone: (770) 488-7100. Product to be stored in Strategic National Stockpile for emergency preparedness and responses.
These agents are essential in the treatment of foodborne botulism and wound botulism. Heptavalent antitoxin (toxins A through G) is available at the Centers for Disease Control and Prevention (CDC). The CDC phone number is (770) 488-7100. Because of the risk of adverse reactions and lack of human clinical data, prophylactic antitoxin is not recommended in patients who are exposed to botulism toxin but who have no symptoms - however, it may be considered after a known high risk exposure as an extraordinary measure[11] .
The most significant improvements in ventilatory and upper airway muscle strength occur over the first few months, and, in some patients, recovery may not be complete for as long as a year. Residual symptoms such as fatigue and shortness of breath may linger for years.[1] Close follow-up is crucial.
Follow-up with other consultants, such as physical medicine and rehabilitation specialists, physical and occupational therapists, nutritionists, and psychiatrists, should be obtained as needed.
Serial neurologic examination focusing on bulbar nerves and respiratory status should be performed with frequency of examination tailored to rapiditiy of disease progression.[1]
Apart from early receipt of BAT (within 12 hours of presentation), there are no known specific signs or symptoms that suggest which patients with botulism will develop respiratory failure, therefore, respiratory monitoring can be extrapolated from management of other neuromuscular syndromes such as Guillian-Barré or Myasthenia Gravis.[61]
Patients with rising end-tidal CO2, forced vital capacity < 20 mL/kg, maximum negative inspiratory force < 30 cm H2O, and maximum expiratory pressure < 40 cm H2O may require intubation.[62]
Dysautonomia due to unopposed sympathetic nervous system stimulation is a hallmark of poisonin with toxin type B and may require cardiac and blood pressure monitoring.[1, 63]
Recovery of ventilatory and upper airway muscle strength in patients who develop respiratory failure is most significant over the first few months. The time for recovery typically ranges from 30-100 days as recovery necessitates axonal regeneration. Artificial respiratory support may be required for months in severe cases.
Transfer is indicated if the patient's condition continues to deteriorate or if the initial hospital is unable to manage the complexities involved.
Prompt notification of public health authorities regarding a suspected case of botulism may prevent further consumption of a contaminated home-canned or commercial food product.
Foodborne botulism is best prevented by strict adherence to recommended home-canning techniques.[64, 65] High-temperature pressure cooking is essential to ensure spore elimination from low-acid fruits and vegetables. Although boiling for 10 minutes kills bacteria and destroys the heat labile botulism toxin, the spores are resistant to heat and can survive boiling for 3-5 hours. Food contaminated by botulism toxins usually has a putrefactive odor; however, contaminated food may also look and taste normal. Hence, terminal heating of toxin-containing food can prevent illness and is an important preventive measure.
Wound botulism is best prevented by prompt thorough debridement of contaminated wound.[1]
Patients undergoing treatment may face a range of potential complications. Hospital-acquired pneumonia, including aspiration pneumonia, is a significant concern, especially when coupled with factors like atelectasis and inadequate secretion clearance that can further heighten the risk of pneumonia.[2, 66] Urinary tract infections may stem from the utilization of Foley catheters,[67] while extended periods of immobility can predispose individuals to skin breakdown and pressure ulcer formation, necessitating proactive preventive measures.[68] The extended use of intravenous catheters can lead to complications such as thrombophlebitis, cellulitis, and line infections.[69]
Patients are also at risk for fungal infections, particularly with prolonged hospital stays or the presence of central venous catheters.[70] It is vital to implement deep vein thrombosis prophylaxis to mitigate the potential for thrombotic events in patients with limited mobility. Stress ulcers, frequently observed in critical care settings, can be managed with proton-pump inhibitors or H2 antagonists for preventative care to minimize this risk.[71]
Other potential complications
Other potential complications include the following:
Botulism due to type A toxin is generally more severe than that caused by type B or E.
Mortality rates vary based on the age of the patient and the type of botulism and have significantly declined over the last century due to improvements in supportive care. The modern mortality for foodborne botulism is 5% or less.[1, 27] Wound botulism carries a mortality rate of roughly 10%.[28] The risk of death due to infant botulism is usually less than 1%.[23]
The recovery period from botulism flaccid paralysis takes weeks to months.[2] Death that occurs early in the course of disease usually is secondary to acute respiratory failure, whereas death later in the course of illness typically is secondary to complications associated with prolonged intensive care (eg, venous thromboembolism or hospital-acquired infection). Some patients demonstrate residual weakness or autonomic dysfunction for 1 year after the onset of the illness. However, most patients achieve full neurologic recovery. Permanent deficits may occur in those who sustain significant hypoxic insults.
Mortality is due to the following:
When preserving food at home, kill C botulinum spores by pressure cooking at 250°F (120°C) for 30 minutes.[33, 64] The toxin can be destroyed by boiling for 10 minutes or cooking at 175°F (80°C) for 30 minutes. Do not eat or taste food from bulging cans. Discard food that smells bad.
Cessation of intravenous drug use prevents wound botulism due to this vehicle.