Outbreak of wound botulism in injecting drug users

(Accepted 6 March 2009; first published online 7 April 2009)SUMMARYBetween October and December 2005, 16 cases of wound botulism were notified to the healthauthorities of North Rhine-Westphalia, Germany. All patients were injecting drug users (IDU)and the epidemiological investigations suggested contaminated injection drugs as the mostprobable source of infection. Clostridium botulinum was cultivated from clinical samples of sixpatients and molecular typing revealed that the different isolates were clonally identical. Twosamples of heroin, one of them provided by a patient, were examined but C. botulinum could notbe isolated. This outbreak demonstrates that IDU are at risk for acquiring wound botulism byinjecting contaminated drugs. A greater awareness of this disease is needed by physicians and aclose cooperation between public health authorities, street workers, operators of shelteredinjecting facilities, and medical centres focusing on IDU is essential to prevent and manageoutbreaks in IDU in a timely manner.Key words: Clostridium botulinum,drugabuse, heroin, outbreak investigation, parenteralmoleculartyping, wound botulism.INTRODUCTIONBotulism is a rare disease, caused by neurotoxin re-lease from the anaerobic spore-forming bacteriaClostridium botulinum. Three main, naturally occur-ring epidemiological types of botulism can be dis-tinguished: foodborne, intestinal colonization (infantform) and wound botulism. In Germany, botulism isa notifiable disease. Between 2001 and 2004, 33 casesof botulism were notified to the German health auth-orities (6–11 per year) of which 29 were considered tobe foodborne in adults, three were infant botulism,and one wound botulism [1].In the days leading up to 3 November 2005, ninecases ofwound botulism in injecting drugusers (IDU)were notified in North Rhine-Westphalia (NRW). Aninvestigation was initiated to identify the extent andthe source of the outbreak in order to prevent theoccurrence of more infections. In this paper we de-scribe the epidemiological and laboratory investiga-tions conducted.METHODSEpidemiological investigationsCase-patients were defined as current IDU, residentin Germany, presenting with acute onset of flaccid