Evolving cluster of severe infective endocarditis with non-toxigenic C. diphtheriae involving people experiencing homelessness and people with substance misuse (including powder or crack cocaine)
UKHSA are currently investigating reports of non-toxigenic C. diphtheriae presenting with severe, fulminant infective endocarditis (IE). Initial case finding has identified 5 cases with onsets from July 2024 to the present date. The majority are young males (30 median; range 23–52 years) with a history of inhalation, smoking or nasal insufflation of heroin or crack cocaine/powdered cocaine. All cases report no intravenous drug use (IVDU), although one acknowledged past use. A significant proportion (60%) have been street homeless in London, although single cases are noted to be resident in the East of England and South-East England.
Cases had rapid disease progression with large vegetations and marked tissue destruction requiring valvular surgery and multiple embolic episodes despite appropriate intravenous antibiotic therapy. One case has died.
Non-toxigenic C. diphtheriae has been isolated in blood cultures from all cases in this investigation and strain typing is underway.