Cluster of Botulism in Intravenous Drug Users: Norway and Scotland


On 29 December 2014, the Norwegian Institute of Public Health (NIPH or Folkehelseinstituttet) was notified of a case of wound botulism in a heroin-injecting drug user living in Oslo. Since then two additional Norwegian cases have been identified in intravenous drug users (IVDU).

Concurrently, on January 6th 2015, Health Protection Scotland reported two linked cases of wound botulism in intravenous drug users, both from the greater Glasgow and Clyde area. Since then an additional five cases have been identified in Scotland. Four of the Scottish cases are currently hospitalised.

Cases occurring in two EU Member States during a short time period suggest the possibility of a batch of heroin contaminated with spores of the anaerobic bacterium Clostridium botulinum. Alternatively, contamination might be with the “cutting” agents - those additives used to bulk up the heroin prior to sale. Given the complex international distribution chain of heroin, the possibility exists that IVDUs in other EU countries are at risk of exposure.

Botulism in well recognised complication in IVDU, being first described in the United States in the early 1980s. Increasingly, botulism came to be associated with the use of heroin (particularly with Mexican “Black Tar” heroin in California and other parts of the South-western US) and the intradermal or intramuscular rather than intravenous routes.

Since that time, clostridial infections in IVDUs have become relatively commonplace, and given the virulence of the strains encountered, disability and death are frequent complications. The disease has been identified in IVDUs in Ireland in the past; in 2000, and in 2008. In addition to botulism, anthrax has been transmitted via contaminated heroin, most notably in Scotland and a number of other European countries in 2010.

The diagnosis of botulism (and other, serious bloodstream infections) in IVDUs can be notoriously difficult, given the shadow existence of such individuals and fear of authorities and requires, on the part of the physician, an awareness of the issue (particularly if there is a warning of a potential contamination incident), and a high degree of clinical suspicion. If the diagnosis is overlooked among the initial differential diagnoses, then considerable (often life-threatening) delays in treatment may result.

Accordingly it is crucial that physicians are aware of this issue and consider the diagnosis in any IVDU (or person who might be an IDVU), as prompt treatment can be lifesaving. In addition IVDUs and their social networks, drug treatment and harm reduction services, should be aware of this cluster. Staff should be actively on the lookout for the signs and symptoms of wound botulism infection among clients and the importance of seeking medical treatment immediately.

There is extensive information on the HPSC’s website relating to the infectious disease risks of injecting drug use.