In Scotland in December 2009, an outbreak of anthrax was identified among injecting drug user (IDUs) centred in Glasgow. The initial Scottish cluster of infection in IDUs began in 2009 and resulted in 119 patients being classed as having anthrax, with 47 of these being confirmed. Fourteen of these cases died. In addition, there were three related cases in England. The responsible isolates had an indistinguishable genetic signature (Ba4599 single-nucleotide polymorphism genotype).

In investigating strain origin, it was subsequently determined that this clone was prevalent in Turkey. Initial UK police and Europol investigations suggested that hide bags used to transport raw opium from production areas in Afghanistan to processing plants (most likely in Turkey) were the source of the anthrax spores. After a lull, in summer 2012, a cluster of five anthrax bloodstream infection cases was identified in Germany, Denmark and France (this cluster was suspected as being caused by illegal importation of heroin from Scotland to Germany). This low-grade outbreak is continuing; to date (March 2013) 13 cases now identified since early June 2012. Seven cases have been affected in the UK – five in England (including four fatalities), one in Scotland and one in Wales. The causative strain of this cluster was again indistinguishable from that responsible for the Scottish cluster. To date, there have been no similar cases in Ireland.

The aim of this guidance is to assist clinicians in Ireland in clinical and microbiological assessment of suspected cases of infection with B. anthracis in IDUs.