Blackwater Fever - A Rare Complication of Malaria

Introduction:

Blackwater fever is a clinical manifestation in individuals living in Plasmodium falciparum endemic areas for an extended period and who do not take quinine regularly. The condition became rare when Chloroquine was introduced as a drug for malaria. However, there were cases associated with Halofantrine and Mefloquine. The exact pathogenesis is unknown, and treatment options are also being debated.

Why Is It Called Blackwater Fever?

Blackwater fever is believed to develop due to Plasmodium falciparum associated with malaria, although various factors are still under debate. The condition got its name because of the black or dark-colored urine resulting from hemoglobin release in the urine.

What Are the Factors Causing Blackwater Fever?

• Unknown Factor: The cause of hemolysis (red blood cell breakdown) in the blood vessels is still unknown. During this phase of hemolysis, red blood cell destruction increases the free hemoglobin levels in the blood, and hemoglobin is excreted in the urine. In addition, severe jaundice (skin and eyes become yellow) and death may result in severe cases.

• Plasmodium Falciparum: It invades the red blood cells and causes hemolysis. In addition, certain cases were due to Plasmodium vivax, Plasmodium knowlesi, and Plasmodium malariae.

• Immunity to Malaria: Blackwater fever was initially noticed in people non-immune to malaria. This is why they develop intravascular hemolysis, and the measure of IgG (immunoglobulin G) can identify if the person is immune.

• Genetics: A survey revealed that not all individuals who took quinine had blackwater fever. But genetic involvement might be the cause of it. In such cases, the MBL (mannose-binding lectin) gene is analyzed.

• Quinine: It is accepted to be one of the causes of blackwater fever due to its interaction with the malarial parasite. Hence, it is not frequently used for treating malaria after introducing Chloroquine. The condition reappeared when quinine was taken because of the resistance against Chloroquine.

What Are the Clinical Features of Blackwater Fever?

The clinical features of blackwater fever include

• Anemia (reduced red blood cells), showing body weakness, and pale skin.

• Black or dark red urine is due to the presence of hemoglobin.

• Abdominal pain.

• Vomiting.

• High fever.

• Chills.

• Rigor (shaking chills along with fever).

• Rapid pulse.

• Extreme weakness.

• Hepatomegaly (enlargement of the liver).

• Splenomegaly (enlargement of the spleen).

• Jaundice, showing yellow-colored urine and yellowish pigmentation in the nails and sclera.

• Renal failure.

How Can Blackwater Fever Be Diagnosed?

Blackwater is a severe and rare condition. Hence, it is not always expected to be a definite diagnosis in most cases. Clinical symptoms such as severe jaundice, anemia, and change in urine color in a person treated for malaria indicate the disease. Later serological, urine, X-rays, ultrasound, and tissue biopsies may be helpful.

What Are the Investigative Findings of Blackwater Fever?

• Jaundice occurs due to the presence of bile pigments in the blood, which is the common cause of death in blackwater fever cases.

• Hemoglobinemia (hemoglobin in blood) can be noticed in the beginning stage of the condition.

• The red blood cells are fragile, and no changes can be identified.

• No spirochetes and treponema were identified in studies, proving no correlation between them and blackwater fever.

• Plasmodium falciparum and Plasmodium vivax are the most commonly identified parasites.

• Tissue changes include fatty degeneration of the cardiac wall, reduced fat content in adrenal glands, and enlarged Malpighian corpuscles of the spleen. In addition, necrosis (cell death) and hemorrhage (rupture of blood vessels) can be identified in the liver.

• Hemolytic substances can be identified in the urine of affected individuals. However, they are not a significant finding in individuals with malaria.

• Quinine can be identified from the urine extracts when the individual experiences hemoglobinuria.

• Clumpy red blood cells can be noticed in the urine.

How Is Blackwater Fever Treated?

The mortality rate of blackwater fever was around 25 to 30 percent initially, but the rate is expected to decrease as various improvements have been made to treat malaria. The treatment modalities are complete rest, intravenous fluid, blood transfusion, antimalarial drugs, and supportive care.

Antimalarial Drugs: Antimalarial drugs destroy the parasite in the liver and red blood cells during its developmental stage. The commonly administered antimalarial drugs are Quinine, Chloroquine, Mefloquine, Amodiaquine, Artemisinims, Primaquine, and Piperaquine. Out of these, Quinine and Mefloquine are expected to be associated with blackwater fever. In addition, the management of blackwater fever with Artemisinin derivatives is still under debate, but it is considered safe and effective, and quinine has to be stopped during its administration. The Artemisinin derivates are Artesunate, Arteether, and Artemether.

Whole Blood Transfusion: In this procedure, the patients receive whole blood containing all the components like red blood cells, white blood cells, platelets, and plasma. It is a more flexible approach to blood transfusion as it is given in its original form.

How Can Blackwater Fever Be Prevented?

• Take care of general health.

• Avoid excessive exposure to the hot or cold part of the day.

• Take quinine regularly to eliminate the parasite and prevent relapses.

• Drugs that prevent and cure anemia can be taken, such as iron tablets.

• Avoid contact with unhealthy people.

• Use proper housing and clothing to prevent mosquito bites.

• Any medical illnesses such as dysentery (diarrhea due to an infection) have to be treated.

• Eat fresh vegetables and drink pure water.

• Avoid alcohol.

• Be cautious while taking depressing drugs and avoid replacing quinine with them.

• Avoid visiting malaria-endemic areas.

Conclusion:

Knowing some rare conditions is essential because these diseases are unexpected and, if left undetected, may be fatal. Similarly, blackwater fever is a rare infection associated with malarial parasites and various other factors. Clinical features are the key to identifying a condition. Likewise, the clinical picture of a condition can be identified by various means and managed by healthcare professionals. Therefore, reporting to the physician when in doubt is the best choice because prevention and early identification are crucial.