Definition of Blackwater Fever

Blackwater fever is an uncommon but serious complication of malaria in which red blood cells are destroyed, releasing hemoglobin into the bloodstream. The hemoglobin is filtered by the kidneys and passes into the urine. The condition occurs almost exclusively with infection by Plasmodium falciparum. Signs and symptoms include

• high fever,
• chills,
• extreme fatigue,
• anemia, and
• dark red or black urine.

Blackwater fever is most common in Africa and Southeast Asia and usually does not develop until a person has resided in an endemic area for 6 months or more and had at least four episodes of malaria. It is also known as malarial hemoglobinuria.