EHEC O45:H2 on the rise – are your laboratories equipped to detect it?

Since the end of August 2025, there have been increasing reports in the media about an EHEC/HUS outbreak (HUS = haemolytic uraemic syndrome) in Germany, particularly in Mecklenburg-Western Pomerania.

The RKI's Epidemiological Bulletin 37/2025 now provides information about the identified outbreak strain: it belongs to the rare serovar O45:H2, carries the virulence markers stx2a and eaeA, and is resistant to several antibiotics (including ampicillin, tetracycline, trimethoprim/sulfamethoxazole). Between 2015 and mid-2025, only 13 strains of this serovar were detected in Germany. The current outbreak is therefore unusual. The exact source of infection is still unclear, and further investigations are ongoing.

For diagnosis, the RKI recommends targeted PCR detection of O45-specific genes (wzx/wzy) and serological confirmation tests.

For laboratories that want to prepare for possible EHEC outbreaks, we offer suitable culture media and transport solutions to support reliable sample collection and analysis.

^{Source: Robert Koch Institute. Epidemiological Bulletin 37/2025 – Enterohaemorrhagic Escherichia coli (EHEC) O45:H2 associated with outbreak in Mecklenburg-Western Pomerania. Berlin: RKI, 11 September 2025. Available online at: www.rki.de/ehec}