Two diphtheria sub-clusters with autochthonous cases in Germany and Poland within a Corynebacterium diphtheriae ST-574 outbreak, 2022 to July 2025.

Within a Corynebacterium diphtheriae ST-574 outbreak comprising mostly migration-associated cases since 2022, Germany detected two sub-clusters in 2025. Among sub-cluster cases with travel information (24/26), 22 were acquired autochthonously. One of two imported cases came from a Polish voivodeship having an additional case. Sub-cluster 1 included 16 cutaneous cases, sub-cluster 2 included six cutaneous and five respiratory cases. One unvaccinated child and two older adults died. Of 27 cases, 12 experienced homelessness. Strengthened immunisation, improved wound care and international surveillance are needed.