Rapid Risk Assessment: Wound botulism in people who inject heroin: Norway and the United Kingdom, 16 February 2015

Risk assessment

European Centre for Disease Prevention and Control. Wound botulism in people who inject heroin, Norway and the United Kingdom – 14 February 2015. Stockholm: ECDC; 2015.

​As of 10 February 2015, 23 cases of botulism have been reported in Norway (eight cases) and Scotland (15 cases), affecting people who inject drugs. All the reported cases used heroin, and it is assumed that the source of the infections is contaminated heroin.

Executive summary

​Today, two EU agencies, the European Centre for Disease Prevention and Control (ECDC) and the EU drugs agency (EMCDDA) have released a joint rapid risk assessment on wound botulism among people who inject heroin. This follows a request by the European Commission’s Directorate-General for Health and Food Safety in response to an increase in the number of cases of wound botulism in this group reported in two EU Member States.

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.

The two EU agencies will continue to monitor the situation through their respective early warning systems (ECDC: ‘Early Warning and Response System’; EMCDDA: ‘EU Early Warning System’).