Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Aug;30(33):2500539.
doi: 10.2807/1560-7917.ES.2025.30.33.2500539.

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

Imme Friederike Roewer de Porto  1   2   3   4 , Alexandra Dangel  2   5 , Lena Schneider  1   2   3   4 , Aleksandra A Zasada  6 , Jonas Haller  7 , Inas Abdelgawad  8   9 , Claudia Siffczyk  1 , Iwona Paradowska-Stankiewicz  10 , Ole Wichmann  1 , Franziska Badenschier  1 , Anja Berger  11   12   13   2 , Cornelius Rau  1   2 , Andreas Sing  11   12   13   2
Affiliations

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

Imme Friederike Roewer de Porto et al. Euro Surveill. 2025 Aug.

Abstract

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.

Keywords: Corynebacterium diphtheriae; Diphtheria; Disease outbreaks; Migration and health; Multilocus Sequence Typing; Next Generation Sequencing; Outbreak investigation; ST-574; Vaccine-preventable disease.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest: None declared

Figures

This figure depicts a graph with a distribution over time of numbers of diphtheria ST-574 cases in Germany and Poland by federal state and voivodeship, manifestation and outcome. Over the period considered by the graph, Germany has a total of 125 cases and Poland has one case. The figure presents two distinct peaks of cases in the autumn and winter of 2022 and 2023. While in 2022, two cases with respiratory diphtheria were reported, in 2023 all cases were reported as cutaneous. In 2024 and 2025, the number of cases declined markedly while the number of respiratory cases increased and during these years five such cases were reported. Among five respiratory cases, three fatal cases can be distinguished.
Figure 1
Number of diphtheria ST-574 confirmed cases in Germany (n = 125) and Poland (n = 1) by federal state or voivodeship, manifestation and clinical outcome, 01 January 2022–03 July 2025
This figure depicts a minimum spanning tree of 133 Corynebacterium diphtheriae ST-574 isolates collected between 2022 and 2025 in Germany, Switzerland, and Poland. There are 125 isolates notified in Germany, seven isolates notified in Switzerland and one isolate notified in Poland depicted. Each circle on the tree represents one or more isolates, with the circle size increasing with increasing number of isolates. Distances between circles indicate allelic differences based on core genome multilocus sequence typing. Closely related clusters of isolates notified in Germany representing migration-associated cases are visible, with two sub-clusters branching off. Sub-cluster 1 includes cases notified in Germany from 2023 to 2025 whereas sub-cluster 2 includes cases notified in Germany and in Poland in 2024 and 2025.
Figure 2
Minimum spanning tree based on core genome multilocus sequence typing analysis of ST-574 C. diphtheriae isolates, 2022–2025 (n = 133), from Germany (n = 125), Poland (n = 1) and Switzerland (n = 7)
See this image and copyright information in PMC

References

    1. Badenschier F, Berger A, Dangel A, Sprenger A, Hobmaier B, Sievers C, et al. Outbreak of imported diphtheria with Corynebacterium diphtheriae among migrants arriving in Germany, 2022. Euro Surveill. 2022;27(46):2200849. 10.2807/1560-7917.ES.2022.27.46.2200849 - DOI - PMC - PubMed
    1. Hoefer A, Seth-Smith H, Palma F, Schindler S, Freschi L, Dangel A, et al. 2022 European Diphtheria Consortium . Corynebacterium diphtheriae Outbreak in Migrant Populations in Europe. N Engl J Med. 2025;392(23):2334-45. 10.1056/NEJMoa2311981 - DOI - PubMed
    1. Berger A, Zasada AA, Dangel A, Piekarska K, Paradowska-Stankiewicz I, Bengs K, et al. A case of fatal respiratory diphtheria imported from Poland to Germany: possible link to an undetected imported diphtheria cluster in Poland? Infection. 2025;1-8. 10.1007/s15010-025-02522-y - DOI - PubMed
    1. Bundesministerium der Justiz und für Verbraucherschutz (BMJV). Gesetz zur Verhütung und Bekämpfung von Infektionskrankheiten beim Menschen (Infektionsschutzgesetz – IfSG). [Act for the prevention and control of human infectious diseases (Protection against infection act)]. Berlin: BMJV; 2000. German. Available from: https://www.gesetze-im-internet.de/ifsg/BJNR104510000.html
    1. Ustawa o zapobieganiu oraz zwalczaniu zakażeń i chorób zakaźnych u ludzi. [Act on preventing and combating infections and infectious diseases in humans. | UNEP Law and Environment Assistance Platform]. Available from: https://leap.unep.org/en/countries/pl/national-legislation/act-preventin...

MeSH terms

LinkOut - more resources