Heat and acid tolerance of Clostridium novyi Type A spores and their survival prior to preparation of heroin for injection.

Clostridium novyi Type A was implicated as a cause of an outbreak of serious illness and deaths among drug users in the United Kingdom who injected heroin intramuscularly. A contaminated batch of heroin was believed to be the source of infection. To test the ability of the outbreak strain to survive certain processes associated with heroin use, it was tested for its ability to survive a range of temperature and pH and the process used in preparation of "street" heroin for injection. C. novyi spores survived temperatures of up to 100 degrees C in aqueous solution for 5 min and survived pH 2.0 at ambient temperatures for a similar time. However, a combination of low pH and raised temperatures reduced survival times. An experiment reconstructing the "street" preparation of heroin demonstrated that any C. novyi spores present would survive this process and thus be capable of initiating infection under the right conditions.