Anthrax infection among heroin users in Scotland during 2009-2010: a case-control study by linkage to a national drug treatment database.

Using a data-linkage approach, we conducted a case-control study to investigate risk factors in an outbreak of anthrax infection among Scottish heroin users. Factors associated with an increased risk of infection included longer injecting history, receiving opioid substitution therapy, and alcohol consumption. Smoking heroin was associated with lower risk of infection.