Berlin reports one death from vibrio infection contracted in Baltic Sea

A person from Berlin has died following a vibrio infection contracted in the Baltic Sea, according to data from the Berlin health authorities. The Berlin State Office for Health and Social Affairs (Lageso) has recorded three cases of vibrio infections so far this year in its latest weekly report on infectious diseases.

Key Details

• Three cases reported in Berlin this year, with one fatality
• Two infections likely developed through wound or skin contact with sea or brackish water in Mecklenburg-Western Pomerania
• All affected individuals were over 75 years old and belonged to the risk group
• All three had wound infections; two developed septic conditions, one of which was fatal

Risk Groups

Vibrio infections pose the greatest threat to:

• Older adults
• Immunocompromised individuals
• People with pre-existing conditions such as diabetes, liver disease, or severe heart disease
• Individuals with open wounds

What Are Vibrios?

Vibrios are bacteria that occur naturally in fresh, brackish, and saltwater. Rising temperatures promote their spread in the Baltic Sea.

"At water temperatures around 20 degrees Celsius, the bacteria can multiply more strongly in the Baltic Sea, in coastal lagoons, and shallow waters," said microbiologist Daniel Herlemann from the Leibniz Institute for Baltic Sea Research Warnemünde (IOW).

Climate Change and Rising Risk

• The Baltic Sea is warming faster than most marine ecosystems in the world, according to researchers from the Geomar Helmholtz Centre for Ocean Research Kiel
• Shallow, rapidly warming coastal areas see significantly higher risk of bacterial occurrence
• The Baltic Sea is particularly affected due to its low salt content

Early Warning System in Development

Dr. Herlemann and his team are working on a new early warning system using drones and artificial intelligence (AI) to detect the bacterium Vibrio vulnificus in the southern Baltic Sea.

Infection Trends in Berlin

| Year | Vibrio Infections Recorded | |------|---------------------------| | 2023 | 5 | | 2024 | 5 | | 2025 | 2 | | 2026 (to date) | 3 |

Health authorities note a comparatively early season of locally acquired vibrio infections this year, likely due to early warming of coastal waters caused by high temperatures. By the 29th calendar week, only one infection had been reported on average in previous years.

Swimming Advisory

In early July, the city of Kiel in Schleswig-Holstein warned against swimming in the Baltic Sea. Bathers are advised to:

• Watch for local skin reactions after water contact
• Seek immediate medical attention if a wound or scratch reddens quickly, swells severely, throbs, or hurts intensely—especially if accompanied by fever or chills
• Inform medical staff that Baltic Sea water was involved

Sources: dpa, epd