Malaria is a mosquito-borne disease caused by a parasite of the genus Plasmodium. The most severe form of malaria is caused by Plasmodium falciparum, which is responsible for the majority of malaria-related deaths.
Parasitemia is the presence of parasites in the blood. In the case of malaria, parasitemia is measured as the number of parasites per microlitre of blood. Parasitemia is an important indicator of the severity of malaria infection.
Hematological findings in Plasmodium falciparum malaria:
Parasitemia can lead to a number of haematological abnormalities, including:
- Anaemia: This is caused by the destruction of red blood cells by the parasites.
- Thrombocytopenia: This is caused by the destruction of platelets by the parasites.
- Leukocytosis: This is caused by the body’s immune response to the parasites.
- Eosinophilia: This is a less common finding, but it can be seen in people with severe malaria.
Pathogenesis of haematological abnormalities in Plasmodium falciparum malaria:
The haematological abnormalities seen in Plasmodium falciparum malaria are caused by a combination of factors, including:
- Direct damage to red blood cells by the parasites: The parasites invade and destroy red blood cells, which leads to anaemia.
- Release of toxins by the parasites: The parasites release toxins that can damage red blood cells and platelets.
- Immune response to the parasites: The body’s immune response to the parasites can also lead to damage to red blood cells and platelets.
Parasitemia is an important indicator of the severity of malaria infection. The haematological abnormalities that can be seen in Plasmodium falciparum malaria are caused by a combination of factors, including direct damage to red blood cells by the parasites, release of toxins by the parasites, and the immune response to the parasites.
The World Health Organization (WHO) defines severe malaria as parasitemia of >5%, or any of the following:
- Neurological symptoms: coma, convulsions, altered consciousness
- Respiratory distress: acute respiratory distress syndrome, pulmonary edema
- Hypoglycemia: blood glucose <2.2 mmol/L
- Renal failure: serum creatinine >3.0 mg/dL
- Liver failure: serum bilirubin >3.0 mg/dL
- Anaemia: haemoglobin <7 g/dL
- Thrombocytopenia: platelet count <100 x 10^9/L
The WHO recommends that people with severe malaria be treated with intravenous antimalarial drugs.