Wound Botulism

Wound botulism is a rare infectious form of botulism (see this term), a rare acquired neuromuscular junction disease with descending flaccid paralysis due to botulinum neurotoxins (BoNTs), produced after infection of wounds by Clostridium botulinum.

Epidemiology

Prevalence is unknown. So far, about 700 cases have been reported worldwide.

Clinical description

Clinical manifestations are similar to other forms of botulism (symmetrical cranial nerve palsy, followed by symmetrical descending flaccid motor paralysis) in particular those of foodborne botulism (see this term), except for the lack of gastrointestinal symptoms (nausea, vomiting, and diarrhea) and the possible presence of fever. The disease, formerly related to traumatic injury, or rarely to surgery, nowadays affects mainly intravenous drug users (IDUs), mostly adults in the fourth or fifth decade of life with a long history of use of injected (``skin popping'') or inhaled drugs and is related to contaminated material or to contaminated black tar heroin. Wound botulism is an infectious but non communicable disease. The incubation period, in case of traumatic injuries, is considered to be 7 to 14 days, but it is difficult to establish for IDUs, as they may inject drugs several times daily.

Etiology

Wound botulism is due to the colonization of a wound, boil, abscess, or inoculation site by C. botulinum spores with subsequent germination and BoNT production in vivo, at the site of infection. The toxin reaches the neuromuscular junctions through the blood stream. The reported cases are related to C.botulinum type A and type B but one case has been related to C.botulinum type E.

Diagnostic methods

Initial diagnosis of wound botulism is based on clinical suspicion in patients with a recent infected wound or history of drug use. Sometimes lesions are not apparent and the presence of deep-seated abscess or sinusitis should be considered. Definitive diagnosis requires laboratory investigations for the detection of BoNTs in serum and wounds. The detection of BoNT-producing Clostridia/i> in wound cultures is generally satisfactory for laboratory diagnosis. Analysis of stools and food may be useful to exclude other forms of botulism.

Differential diagnosis

Differential diagnosis includes myasthenia gravis, Guillain-Barré syndrome (Miller-Fisher syndrome), Lambert-Eaton syndrome, and foodborne and adult intestinal botulism (see these terms).

Management and treatment

Antitoxin therapy must be associated with supportive care in an intensive care unit (ICU). Antitoxin therapy is effective when it is administrated at the onset of symptoms. In Europe, the formulation currently available for adults is trivalent (anti A, B, E). A heptavalent (anti A to G) product is also available. In the USA, a bivalent (anti A, B) and a monovalent (anti E) antitoxin are available. Specific management of wound botulism includes surgical debridement of the wound with irrigation to remove the source of the toxin and antibiotic therapy with penicillin and metronidazole. Aminoglycoside and clindamycin should be avoided as they may exacerbate the neuromuscular blockade.

Prognosis

With appropriate intensive care, prognosis is good; death occurs in only 7% of cases and results from respiratory failure. Wound botulism may recur in IDUs.