Morphology of Malaria parasites

MORPHOLOGY OF MALARIAL PARASITES

WHAT IS MALARIA?

•Malaria is a disease caused by parasite that enters the blood.

•This parasite is a protozoan called plasmodium.

•3 to 700 million people get malaria each year, but only kills 1 to 2 million

•40% of the worlds population lives in malaria zones

•Malaria zones are: Africa, India, Middle East, Southeast Asia, Central and South America, Eastern Europe, and the South Pacific

 MALARIA PARASITE (PLASMODIUM) 

•Pathogen of malaria

Plasmodium vivax

Plasmodium falciparum

Plasmodium malariae

Plasmodium ovale

•P.vivax ; P.falciparum are more common

•Plasmodium is a wide distribution in many tropical or subtropical regions of the world

MALARIA – VECTOR

Anopheles stephensii - common vector in India

Plasmodium vivax - Various stages seen microscopically

Plasmodium vivax

Early trophozoite (ring form) 

         

•                  Red nucleus on the ring, with light blue cytoplasm
•                  Infected RBCs are enlarged

Late trophozoite

                  It is irregular shape like ameboid form with pseudopodia; within cytoplasm ,brown pigment granules (malarial pigment---haemozoin) appear.

Immature schizont

        

   Oval in shape, nucleus divided into 2-4 or more, malarial pigment begins to

   concentrate in a mass. 

Mature schizont

              Nucleus divided into 12-24; and cytoplasm also divided , each nucleus surrounded by a portion of cytoplasm to form merozoites, malarial pigment clumped

Male gametocyte(Microgametocyte)

      

Oval in shape

Diffused nucleus in centre 

Diffused Pigments

Female gametocyte(Macrogametocyte)

  

Oval in shape

Compact nucleus in corner

Diagnostic points

ØRed cells containing parasites are usually enlarged.

ØSchuffner's dots are frequently present in the red cells as shown above.

ØThe mature ring forms tend to be large and coarse.

ØDeveloping forms are frequently present.

Plasmodium falciparum

Early trophozoite (ring form)

Ø1or 2 red nuclei on the ring-like light blue cytoplasm ; multiple infection in a cell.

ØInfected RBCs normal in size

Male gametocyte (Microgametocyte)

ØBanana shaped

ØDiffused nucleus in the centre

ØMalarial pigment diffused

Female gametocyte (Macrogametocyte)

ØCrescent shaped

ØCompact  nucleus in centre

Diagnostic points

ØRed Cells are not enlarged.

ØRings appear fine and delicate and there may be several in one cell.

ØSome rings may have two chromatin dots.

ØPresence of marginal or applique forms.

ØIt is unusual to see developing forms in peripheral blood films.

ØGametocytes have a characteristic crescent shape appearance.
However, they do not usually appear in the blood for the first four weeks of infection

ØMaurer's dots may be present.

Differentiating characteristics of Plasmodium sp.

BY:

ESWARI VASANTH

SENIOR TECHNICIAN

ROHFW, CHENNAI-90