Malaria is a disease caused by a parasitic protozoan belonging to the genus Plasmodium that is transmitted to people through the bites of infected female Anopheles mosquitoes. It's a major concern in many tropical and subtropical regions of the world.

The malaria parasite, once it enters the human body, travels to the liver where it matures and reproduces. After a few days to a week, the mature parasites leave the liver and start invading red blood cells. Inside these cells, the parasites multiply rapidly until the cell bursts open, allowing the parasites to further invade other red blood cells. This invasion, multiplication, and bursting process in the red blood cells are what cause the typical symptoms of malaria which include high fevers, shaking chills, and flu-like illness.

Diagnosing malaria often involves making a blood smear of the patient’s blood, staining it with a dye like Giemsa stain, and examining it under a microscope (Figure 1). This allows medical professionals to visualize the malaria parasites inside the red blood cells.

Malaria is typically treated with antimalarial medications. The type and length of treatment depend on various factors, including the specific type of malaria parasite causing the infection, the severity of symptoms, and the location of the infection.

Microscopic image showing red blood cells. Some of the red blood cells appear spiky around their edge rather than their regular smooth, discoid shape. In addition, many of the red blood cells contain a small, darkly stained ring.

Figure 1. Blood smear showing red blood cells infected with Plasmodium and stained with Giemsa.