Fisheries

Vistula lagoon disease: five suspected cases after consumption of fish from the Vistula Lagoon - authorities warn a

Recently, five suspected cases of the so-called Vistula lagoon disease (Choroba Zalewu Wiślanego) were reported in the Nowy Dwór County. All affected individuals had consumed significant quantities of bottom-dwelling fish, primarily flounder and eel, caught in the Vistula Lagoon. Patients were hospitalized with clinical symptoms including severe muscle pain, dark urine discoloration, and signs of kidney failure.

Kamil Kusier executive editor 16.05.2025, 07:52 Reading time: 2 min

Silhouette of a fishing boat on the Vistula Lagoon against an orange sunset glow — fot. Alan Szmyt / Wikimedia Commons

In brief

Nowy Dwór county recorded five suspected cases of Vistula Lagoon disease in people who had eaten large amounts of bottom fish, mainly flounder and eel, from the Vistula Lagoon. Symptoms, including severe muscle pain, dark urine and signs of kidney failure, appeared within tens of hours after eating up to three half-kilogram portions of fish, hospital stays were short and no patient needed dialysis. The Pomeranian and Warmian-Masurian Voivodes coordinated water sampling and the delivery of fish samples to the National Veterinary Research Institute in Puławy. Authorities advise limiting consumption of flounder and eel from the Vistula Lagoon as a precaution.

Symptoms appeared within several dozen hours after consuming even three half-kilogram portions of fish. Although hospital stays were brief and none of the patients required dialysis, the incidents have raised concerns among health authorities and food safety regulators.

What is Vistula lagoon disease?

Known for over a century, Vistula lagoon disease is a rare condition characterized by rhabdomyolysis causing severe skeletal muscle damage. Its precise cause remains unclear, but it is suspected that naturally occurring toxins accumulating in the muscle tissue of bottom-feeding fish such as flounder, eel, and burbot are responsible.

Typical symptoms manifest shortly after ingestion and include muscle pain, darkened urine due to muscle breakdown (myoglobinuria), and in rare cases, acute kidney failure. Usually, symptoms resolve spontaneously or after adequate hydration in medical settings, though dialysis may be necessary in exceptional cases.

Authorities’ response and ongoing investigations in the Pomeranian region

In response to the reported cases, the Pomeranian Voivode together with the Warmian-Masurian Voivode have coordinated actions among subordinate services. In cooperation with the Chief Sanitary Inspectorate and the Regional Environmental Protection Inspectorate, water samples from the Vistula Lagoon were collected and sent for analysis. Simultaneously, the Pomeranian Chief Veterinary Officer and the State Sanitary Inspectorate submitted fresh and frozen fish samples to the National Veterinary Research Institute (PIWet) in Puławy for toxicological testing.

The Pomeranian Public Health Center and the State Sanitary Inspectorate continue to monitor the situation closely, providing regular updates on suspected cases and laboratory results.

Recommendations for residents and fishermen

Until toxicological results become available, which may take several weeks, authorities strongly recommend limiting consumption of large quantities of flounder and eel caught in the Vistula Lagoon to protect public health.

Individuals experiencing symptoms such as muscle pain, dark urine, or other concerning signs after eating fish are advised to seek immediate medical attention. Vulnerable groups including the elderly, people with chronic illnesses, and children should exercise particular caution.

Implications for the fisheries sector – what next?

Despite being described for over 100 years, Vistula lagoon disease still poses many unanswered questions within the scientific community and fishing industry. The lack of a clearly identified toxin complicates rapid response efforts. Seasonal occurrence patterns suggest environmental factors may influence the presence of pathogens or toxins in the lagoon ecosystem.

This situation presents a significant challenge for local fishermen and enterprises involved in fish harvesting and processing. Collaboration with research institutions and adherence to sanitary recommendations remain essential to ensuring consumer safety and protecting the regional fish market.

Source: Gazeta Morska · Compiled by: Kamil Kusier