What Is Malaria?
Malaria is a parasitic infection caused when a female Anopheles mosquito with a malarial parasite bites a person. It acts as a vector to carry the parasite and spreads the disease. The mosquito becomes infected when the blood is drawn from an infected person containing the parasite. When that mosquito bites another person, the parasite is transferred to that person, leading to the infection's spread. Plasmodium is a single-celled parasite with four common species causing malaria.
The most common species related to renal dysfunction or failure are P. falciparum and P. malariae. Falciparum malaria is a life-threatening disease and can cause liver and kidney failure, convulsions, and coma. The symptoms of the malarial infection appear after 7 to 30 days of the infection. Symptoms appear in cycles, including fever, chills, headache, nausea, and vomiting. The episode of the malarial infection starts with chills followed by high fever and sweating, which then returns to normal temperature.
What Is Nephropathy?
The kidneys are made up of small filtering units called the nephrons. The deterioration of the functions of the nephrons is called nephropathy. Acute kidney infection is caused by different Plasmodium species like falciparum and ovale. The kidney condition can worsen due to low hydration and fluid loss caused by vomiting, sweating, and dehydration. Chronic kidney disease is generally associated with malaria in patients suffering from repeated episodes of infection. Acute kidney infection is the most common complication of malaria and can occur in patients with a severe disease, P.falciparum.
How Does Malaria Cause Renal Failure?
Amongst all the Plasmodium species, P. falciparum causes the most severe form of malaria and is mainly responsible for acute kidney infections. The parasite in falciparum infection attacks the red blood cells (erythrocytes). These parasitized erythrocytes start the three mechanisms:
Hemodynamic disturbances include parasitized erythrocytes, which adhere to adjacent healthy red blood cells, blood platelets, and the capillary endothelium. This results in intravascular knots and obstructs the microcirculation inside the kidneys.
Immunological dysfunction happens when the parasite interacts with the body's innate immune system, and activation of B cells occurs, which causes the production of cytokines leading to immunosuppression. This mechanism produces antibodies leading to the formation of an immune complex, which is further related to injury to the glomerulus.
Metabolic disturbances include hemolysis of the red blood cells, causing anemia, jaundice, bleeding, and acute renal failure.
What Are the Symptoms of Malarial Nephropathy?
Proteinuria - It is the presence of protein in increased levels in the urine.
Microalbuminuria - A condition wherein the albumin level in the urine is in the range of 30 to 300 mg (less than 30 mg is considered the normal level).
Jaundice - Increase in the amount of bilirubin due to excessive destruction of red blood cells.
Anemia - Decrease in the hemoglobin concentration.
Hypoxia - Decrease in oxygen supply to the tissues.
Chills, Fever, and Sweating - These symptoms return to normal temperature.
Hyponatremia - Decrease in the sodium content in the blood.
Hyperkalemia - Increase in potassium content in the blood.
Oliguria or Anuria - Decrease in or complete cessation of urine.
Electrolyte Disturbance - Imbalance in electrolyte concentration of the blood.
Malarial Glomerulonephritis - P. falciparum infection leading to glomerulonephritis (disease that injures the glomeruli, the part of the kidney that filters blood) is uncommon. Children are more affected by this complication. The correct incidence of the malaria complication is unknown, but it is estimated to be around 18 percent.
Nephrotic Syndrome Associated With Malaria - P. falciparum infection resulting in nephrotic syndrome (a kidney disorder characterized by the release of excessive protein in urine) is uncommon.
What Are the Risk Factors of Malarial Nephropathy?
Risk factors for high mortality include acute illness, advanced age, increased parasitemia, hyperkalemia, oliguria, hypotension, severe anemia, jaundice, and altered consciousness level. Patients with poor prognoses may suffer from multiple organ involvement, severe diarrhea, and respiratory distress.
How to Diagnose Malarial Nephropathy?
Signs and symptoms of malaria include fever, sweat, flu-like illness, chills, malaise, headache, muscle aches, tiredness, nausea, vomiting, and diarrhea may occur. Malaria may cause anemia (decrease in red blood cell count) and jaundice (yellowish discoloration of the skin and eyes) because of the loss of red blood cells. If untreated, the infection becomes severe and may cause kidney failure, coma, and death.
The precise way to diagnose malaria is through blood examination for the presence of the malarial parasites.
P. falciparum malaria-causing kidney injury can be diagnosed by urine analysis containing the kidney injury biomarkers, neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1), which have the advantage of detecting AKI earlier than creatinine.
How to Treat Malarial Nephropathy?
Treatment of malarial nephropathy includes antimalarial drugs and measures that require correction of water and electrolyte disturbances, fluid replacement, and dialysis. The drug of choice for the treatment of malaria is Chloroquine. P. falciparum has resistance to Chloroquine.
Therefore, therapy should include:
Primaquine is used in P. vivax and P. ovale to prevent relapse. Intravenous Quinine is widely used to treat cerebral and other serious complications of falciparum malariae. Antimalarial drug doses should be based on the patient's weight to provide good efficacy. For severe malaria treatment, intravenous or intramuscular antimalarial drugs are given.
The most effective drug in treating severe malaria is Artesunate, which is given for at least 24 hours. The solution of Artesunate is diluted in 5 ml of 5 percent dextrose and given intravenously or intramuscularly.
Dialysis should be considered in acute kidney injury treatment for more effectiveness. Antimalarial drugs are not filtered in hemofiltration dialysis, so dialysis does not interfere with the specific treatment of malaria. Further increase in the development of vaccines is required to prevent severe cases leading to renal failure. Malaria can be more severe in pregnant women than in women who are not. Malaria can increase the risk of pregnancy problems like prematurity and miscarriage.
Taking antimalarial drugs to kill the parasites as soon as diagnosed can prevent the illness. Prevent oneself from mosquito bites, especially at night, which can be done by using insect repellent and wearing long-sleeved clothing. A person who becomes ill with a fever, malaria, or flu-like illness during travel should seek medical care immediately. If one is traveling to a country where malaria transmission occurs, precautions should be taken against contracting malaria. Treatment of malaria-associated nephropathy should include antimalarial drugs and measures to control acute kidney injury. Malaria should be treated sooner as it causes severe damage to multiple organs.