UKHSA Update on infection with non-toxigenic C. diphtheriae involving people experiencing homelessness and with substance use in England

The updated national diphtheria guidance now includes support for severe C. diphtheriae cases and managing infection clusters in vulnerable settings. Cases should follow current protocols as set out below, and contact tracing or antibiotic prophylaxis isn’t needed for contacts of non-toxigenic cases; queries can be directed to UKHSA Incident Lead rebecca.corder@ukhsa.gov.uk.

20250721_BN02025_28_non-toxigenic diphtheria update July 2025 v01.00