Malaria is one of the most frightening infections caused by Plasmodium species. It leads to one million deaths globally every year. The deaths occur mainly in tropical Africa, parts of south and central America, India and south-east Asia. African subcontinent is highly affected, as 90% deaths due to malaria occur. Out of 90% deaths, 70% deaths arise in children having less than 5 years of age. There are five species of Plasmodium known to cause malaria in humans i.e. Plasmodium (P.) vivax, P. falciparum, P. malariae, P. ovale, P. knowlesis. P. knowlesis spread malaria from Anopheles mosquito infected from monkey to humans referred to as zoonotic transmission. Plasmodium parasite needs two hosts to complete its phase of life i.e. female Anopheles mosquito (acting as a vector) and human. Life sequence of the Plasmodium parasite is shown in the figure.
Symptoms of malaria are fever with chills, anemia and in critical cases causes cerebral malaria which can lead to death. It affects major organs like the brain, heart, liver, and kidneys causing encephalopathy, congestive heart failure, splenomegaly, and hemoglobinuric nephrosis. Severe P. falciparum malaria causes cerebral malaria, hypoglycemia, renal impairments, severe anemia, jaundice, pulmonary edema, hemoglobinuria and acidosis, congestive heart failure and hypotensive shock.
Diagnosis of malaria is done by detecting antigens of the parasite in the blood which is called a blood smear test or by histopathological studies.
Various anti-malarial drugs used in malaria are Quinine, Chloroquine, 4-aminoquinoline, Amodiaquinine, Quinoline and Artemisinin and its derivatives are used.
The malaria pathogenesis includes the interaction of the parasite with red blood cells, which leads to the formation of red blood cell rosettes, rigidity, and deformity of the cell membranes of blood cells. Hemolysis leading to the anemic condition. Microcirculatory dysfunction which results in organ dysfunction and tissue hypoxia.
Various organs affected are spleen causing splenomegaly, a heart where focal hypoxic lesions occur, lungs get congested and fibrin gets deposited, cerebral oedema in the brain, the liver gets enlarged, hemoglobinuric nephrosis in kidney and gastrointestinal tract gets congested in severe malaria.