Two countries, Norway and Scotland have been seeing a significant number of wound botulism cases beginning in December prompting European health officials to release a rapid risk assessment Monday.

Public domain photo/Psychonaught
Public domain photo/Psychonaught

The European Centre for Disease Prevention and Control (ECDC) and the EU drugs agency (EMCDDA) did the assessment at the instruction of the European Commission’s Directorate-General for Health and Food Safety.

Between December 2014 and 10 February 2015, 23 cases of wound botulism among people who had injected heroin were reported in Norway (8 confirmed cases) and Scotland (6 confirmed and 9 probable cases). All of the cases were reported to have involved heroin use and most involved the intramuscular injection of the drug. In all the Norwegian cases, the individuals had bought the drugs in the Oslo area. For all the UK cases where the information is available, the drugs were bought in, or sourced from, Glasgow.

The source of infection is thought to be contaminated heroin. The geographical distribution of the potentially contaminated heroin is unknown at this time; however, if the contaminated heroin is still in circulation, further cases may occur.

It is currently unknown whether or not there is a link between the outbreaks in the two countries. However, based on information currently available on the temporal and geographic clustering of cases, it is possible that the cases are connected through exposure to the same batch, or batches, of contaminated heroin.

The risk of additional cases occurring in other countries of the EU/EEA depends on the stage in the heroin distribution chain where the contamination took place. If the contamination occurred at an early (wholesale) level of heroin distribution, new cases may occur in other countries. As Clostridium botulinum is not transmitted from person to person, the risk to the general population in relation to these cases is negligible.