A resident of Berlin died after being infected with vibrios during a stay on the coast of the Baltic Sea in the federal state of Mecklenburg – Western Pomerania. This was reported by the Berlin State Office for Health and Social Affairs (Lageso). This is the first registered fatal case of such an infection since 2023, [reports](https://www.welt.de/regionales/mecklenburg-vorpommern/article6a68b9cace0aac7f44e41291/an-ostsee-mit-vibrionen-infiziert-ein-todesfall-in-berlin.html?fbclid=IwY2xjawTWb9BleHRuA2FlbQIxMABicmlkETFQS0VPVmQ4MTU4b2J5c0FPc3J0YwZhcHBfaWQQMjIyMDM5MTc4ODIwMDg5MgABHm5W9XE4WXWWxeRSQxbQCE1HGujqjBa5ZxEbGWe4jB9la8IwKQkCGr2mtirY_aem_rvXBQXqetDdcjjN8LXRYdA) Welt. Since the beginning of 2026, three cases of vibrios infection have been registered in Berlin. Two of the infected had also vacationed in Mecklenburg – Western Pomerania. According to specialists, the infection occurred when open wounds or damaged skin came into contact with seawater or brackish water. All three patients developed a wound infection, and in two cases, the disease progressed to sepsis. One of the infected individuals died. Symptoms appeared on June 22, and death occurred on July 13. All the infected were over 75 years old. Doctors remind that the most vulnerable to this infection are elderly people, patients with weakened immune systems, diabetes, liver diseases, and severe cardiovascular diseases. The risk is particularly high for individuals with open wounds. ### Why the Danger Increases in Summer Vibrios are bacteria that naturally inhabit fresh, brackish, and seawater. When water temperatures exceed 20 degrees Celsius, they begin to multiply rapidly. Shallow waters, which warm quickly, create particularly favorable conditions for them. The Baltic Sea is considered one of the most favorable environments for these bacteria due to its relatively low salinity. According to Lageso, two cases of vibrios infection were registered in Berlin in 2025, and five cases in both 2023 and 2024. This year, however, the season started noticeably earlier due to abnormally warm weather and the rapid warming of coastal waters. In Mecklenburg – Western Pomerania, three cases of infection have also been registered since the beginning of the year. Over the past five years, 28 such infections have been identified in the region, four of which resulted in death. ### Scientists Are Creating a Warning System Specialists from the Leibniz Institute for Baltic Sea Research in Warnemünde are working on an early warning system for the danger of vibrios infection. Using drones, scientists collect data on water temperature, salinity, currents, and the blooming of blue-green algae. Artificial intelligence then analyzes the information and assesses the risk of infection for specific coastal areas. Recent research has shown that the appearance of dangerous bacteria can be predicted four to five weeks in advance. Additionally, scientists have found that mass blooming of blue-green algae promotes the multiplication of vibrios, as decomposing algae become a source of nutrients for them. Experts recommend that individuals in risk groups avoid entering warm seawater when they have open wounds or skin damage. As the climate warms, the risk of vibrios infection in the Baltic Sea may increase, making early warning systems increasingly relevant.