Officials in Brazil have issued a warning after a woman became sick from a rare disease after eating fish.

The municipality of Goianésia, which is in the state of Goiás, said it is monitoring the case of a patient infected with Haff disease, also known as black urine disease. She is hospitalized in the intensive care unit (ICU) and her health status is stable but she requires specific care.

She had gastrointestinal symptoms on June 24 and sought care at hospital two days later with loss of muscle strength, body pain, and dark colored urine, wher she was admitted to the ICU.

Local media reported the affected woman was 27-year-old Kelly Silva who became ill after eating fish at a restaurant in the city.

Health officials are looking out for possible new cases and an official epidemiological alert was issued to hospitals to watch for signs or symptoms related to the disease.

Haff disease, or black urine disease, is caused by a toxin found in some fish. Symptoms include sudden extreme muscle stiffness, muscle pain, chest pain, difficulty breathing, numbness, loss of strength throughout the body, and dark brown urine. They usually appear between two and 24 hours after eating fish or shellfish.

It is not known if the odorless and tasteless toxin, which cannot be destroyed by cooking, is caused by fish not being properly stored and packaged or by what they eat.

The health department in the State of Bahia recorded 40 cases in late 2020. This year, two people were sick in Recife and one died.

A total of 29 cases of Haff disease were reported in the United States from 1984 to 2014. They have been linked to carp, buffalo fish, crawfish, or Atlantic salmon.