Botulism is a rare but serious illness caused by botulintoxin. The toxin is produced by the bacteria Clostridium botulinum. The HPSC was informed of four cases of wound botulism – all affecting injecting drug users – in late November 2008. Wound botulism is a rare condition. The condition is caused by bacteria that are commonly found as spores in soil or gravel and can be acquired if a wound is contaminated by such material. The bacteria grow in skin abscesses as a result of injecting heroin but the bacteria can also reproduce in the nasal passages as a result of snorting cocaine. Symptoms of botulism usually develop about 12–36 hours after exposure to the toxin and normally begin with blurred vision, difficulty swallowing, difficulty speaking and occasionally breathing problems. Diarrhoea and vomiting can also occur and the disease can progress to paralysis. In recent years this type of botulism has been most commonly reported among chronic drug users, in Ireland and elsewhere. Most people (90–95%) with botulism will recover with treatment.