Blackwater fever

Summary about Disease


Blackwater fever is a serious complication of malaria, specifically Plasmodium falciparum infections. It is characterized by a sudden and massive destruction of red blood cells (hemolysis), leading to hemoglobinuria (hemoglobin in the urine, giving it a dark, almost black, color), anemia, and kidney failure. It is now relatively rare due to improved malaria control and treatment.

Symptoms


Dark red or black urine (hemoglobinuria)

Rapid onset of anemia (fatigue, weakness, shortness of breath)

Fever

Chills

Jaundice (yellowing of the skin and eyes)

Abdominal pain

Back pain

Kidney failure (decreased urine output, swelling)

Confusion or altered mental status

Causes


Blackwater fever is primarily caused by:

Plasmodium falciparum malaria infection.

It often occurs in individuals with partial immunity to malaria who have been exposed to repeated infections.

Quinine: Historically, quinine use, paradoxically, was associated with triggering Blackwater fever in some individuals. It is much less common now with current antimalarial drugs.

Medicine Used


Antimalarial drugs: Prompt treatment of the underlying malaria infection is crucial. Current antimalarial medications like artemisinin-based combination therapies (ACTs) are typically used.

Supportive care: This is critical and includes:

Blood transfusions to treat severe anemia.

Intravenous fluids to maintain hydration and kidney function.

Dialysis if kidney failure develops.

Treatment of any other complications.

Is Communicable


Blackwater fever itself is NOT communicable. It is a complication of malaria. Malaria is transmitted through the bite of infected Anopheles mosquitoes.

Precautions


The best precautions are those to prevent malaria:

Mosquito bite prevention:

Use insect repellent containing DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), para-menthane-diol (PMD), or 2-undecanone.

Wear long sleeves and pants, especially during dawn and dusk when mosquitoes are most active.

Use mosquito nets (preferably insecticide-treated nets) while sleeping.

Stay in screened or air-conditioned rooms.

Prophylactic antimalarial medication: If traveling to a malaria-endemic area, take prescribed antimalarial drugs as directed by a healthcare professional.

Prompt diagnosis and treatment of malaria: Seek medical attention immediately if you develop symptoms of malaria (fever, chills, sweats, headache, body aches) after being in a malaria-endemic area.

How long does an outbreak last?


An "outbreak" in the context of Blackwater fever refers to the acute episode of hemolysis. The duration of the acute episode can vary but typically lasts for:

Several days to a few weeks. The critical period is the first few days where rapid hemolysis and kidney failure can occur.

Recovery depends on the severity of the episode and how quickly treatment is initiated.

The underlying malaria infection needs to be treated to prevent further complications.

How is it diagnosed?


Diagnosis involves:

Clinical presentation: The characteristic dark urine, anemia, fever, and jaundice raise suspicion.

Blood tests:

Complete blood count (CBC) to assess anemia.

Blood smear or rapid diagnostic test (RDT) to confirm Plasmodium falciparum malaria infection.

Kidney function tests (BUN, creatinine) to evaluate kidney damage.

Liver function tests (LFTs) to assess liver involvement.

Lactate dehydrogenase (LDH) is typically very high, indicating haemolysis

Urine analysis: To detect hemoglobinuria.

Other tests: May be needed to rule out other causes of hemolysis.

Timeline of Symptoms


The onset of Blackwater fever symptoms is usually rapid:

Initial malaria symptoms: Fever, chills, sweats, headache, and muscle aches (can precede Blackwater fever by days or weeks).

Sudden onset of hemolysis:

Dark urine (hemoglobinuria) appears abruptly.

Rapid worsening of anemia symptoms (fatigue, weakness, shortness of breath).

Fever and chills may intensify.

Jaundice develops.

Abdominal and back pain may occur.

Kidney failure: If untreated, decreased urine output and swelling can develop within days.

Important Considerations


Blackwater fever is a medical emergency. Prompt diagnosis and treatment are crucial to prevent serious complications and death.

Individuals with partial immunity to malaria are at higher risk.

The use of quinine should be carefully considered, as it has been implicated in triggering Blackwater fever in some cases (though now other antimalarial treatments are preferred).

Supportive care, including blood transfusions and dialysis, is essential for managing the complications of hemolysis and kidney failure.

Prevention of malaria remains the most effective way to prevent Blackwater fever.