Notes on Philippine Medically Important Protozoans Part 3 (Malarian spp.) Meccar Moniem Elino, BSBio IV , Davao Doctors College Instructor: Mrs. Chalee Sienes-Reyes, RMT, MSMT, Ph.D

Reference: Philippine textbook of Medical Parasitology 2nd ed.(2004) UP. Edited by Vicente Y. Belizario, Jr. and Winifreda U. de Leon

RBC Stage Size of RBC Dots Trophozoite Schizont Disease Cytoplasm Pigment No. of

Merozoite Gametocyte

P.vivax Young enlarge Schauffner's

Red blood cells infected by P. vivax are often

larger than uninfected red blood cells.

They are approximately 1.5 times the size of a

normal cell.

showing the large number of

merozoites typical of this species (16-

24). Also note the larger size compared to a normal red blood

cell.

Benign Tertian;

merozoites released every 48

hrs

Irregular, ameboid in trophozoite, has

spread out appearance

Golden brown, incons-picuous

12-24 Average is

16 rounded

P. malariae Mature normal Zeimann's

containing merozoites (6 to

12) giving a coarse granular

appearance.

Quartan; merozoites

released every 36-

48 hrs

Rounded, compact trophozoite with dense cytoplasm/

band form troph are rarely seen

Dark brown, cons-

picuous

6-12 Average is

8, “rosette” schizonts

are sometimes

seen

rounded

P. ovale Young enlarge Schauffner's

Benign Tertian;

merozoites released every 48

hrs

Rounded, compact trophozoite with dense cytoplasm/

band form troph are rarely seen

Dark brown, cons-

picuous

6-12 Average is

8, “rosette” schizonts

are sometimes

seen

rounded

P. falciparum all stage normal/multiple

infection Maurer's

Early trophozoites have the characteristic signet

ring shape. Also, unique to P.

falciparum is the presence of multiple trophozoites

in one cell.

The gametocytes of P. falciparum have

a crescent or banana shape.

Malignant Tertian;

merozoites released every 72

hrs

Young rings are small, delicate,

often with double chromatin mass

Black coarse and

cons-picuous in

gametocyte

6-32 Average is

20-24

crescent or banana