Correct!
2. Botulism
Botulism is a rare and potentially life threatening neuroparalytic condition mediated by a neurotoxin produced by the bacterium Clostridium botulinum (1). There are six forms of botulism distinguished by the route of infection: foodborne, infant, adult enteric, wound, iatrogenic and inhalation. According to the Centers for Disease Control and Prevention (CDC), there are fewer than 5 reported cases of wound botulism in the US per year (2). Despite clostridium being ubiquitous, these tend to occur only in patients who subcutaneously inject black tar heroin, and may be an under recognized cause of death in presumed opioid over dose (3,4).
When C. botulinum spores are injected into a wound, the devitalized tissue provides the ideal medium for anaerobic growth. Seven serotypes of toxin can be produced, of which toxins A, B, E and F can cause human disease. Paralysis occurs through toxin-mediated blockade of neuromuscular transmission in cholinergic nerve fibers.
It is unclear why black tar heroin injection subcutaneously or intramuscularly (“skin popping”) vs. intravenous injection is associated with wound botulism. Black tar heroin is becoming more prevalent in the US as it is a relatively crude and unrefined opiate which does not require the complex equipment, expensive chemicals and lengthy steps required to produce pure heroin or “china white” (Figure 4).
Figure 4. Photographs of black heroin.
Botulism was suspected given the clinical picture and active black tar heroin use. The anti-toxin was acquired from the CDC and administered.
Diagnosis was later confirmed by murine bioassay of serum, wound and stool and anaerobic wound culture. This case met CDC criteria for report of confirmed wound botulism (Table 1).
Table 1. CDC Case Criteria for Would Botulism
Clinical Description
An illness resulting from toxin produced by Clostridium botulinum that has infected a wound. Common symptoms are diplopia, blurred vision, and bulbar weakness. Symmetric paralysis may progress rapidly.
Laboratory Criteria for Diagnosis
- Detection of botulinum toxin in serum, OR
- Isolation of Clostridium botulinum from wound
Case Classification
Probable
A clinically compatible case in a patient who has no suspected exposure to contaminated food and who has either a history of a fresh, contaminated wound during the 2 weeks before onset of symptoms, or a history of injection drug use within the 2 weeks before onset of symptoms.
Confirmed
A clinically compatible case that is laboratory confirmed in a patient who has no suspected exposure to contaminated food and who has a history of a fresh, contaminated wound during the 2 weeks before onset of symptoms, or a history of injection drug use within the 2 weeks before onset of symptoms.
Although rare, botulism is important to keep in the differential diagnosis, especially in patients who inject black tar heroin subcutaneously as early recognition, prompt anti-toxin administration, and complete source control are essential in preventing poor outcomes in an otherwise reversible neurological condition.
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