Plasmodium Species Guide: How to Identify Plasmodium vivax Under the Microscope

 

P. vivax 🍼

• Enlarged, ameboid-shaped cells.

• Schizonts are large and visible in thin film.

• Gametocytes are round, unlike falciparum's banana-shape.

• Also infects reticulocytes (young red blood cells), leading to cell enlargement.

Fig. 1: P. vivax ring-form trophozoites in a thick smear. I seriously doubt that I would know that these are vivax if I saw it in a smear. What about you? Image credit: CDC (https://www.cdc.gov/dpdx/malaria/index.html)

Fig. 2: Additional P. vivax ring-form trophozoites in a thick smear. Image credit: CDC (https://www.cdc.gov/dpdx/malaria/index.html)

Fig. 3: An example of P. vivax ring-form trophozoites in a thin smear. Image credit: CDC (https://www.cdc.gov/dpdx/malaria/index.html)

Fig. 4: Another example of P. vivax ring-form trophozoites in thin smear. This image has more ring-forms in view, than the previous image. Image credit: CDC (https://www.cdc.gov/dpdx/malaria/index.html)

 

Fig. 5: The amoeboid appearance of P. vivax trophozoites in a thick smear. Image credit: CDC (https://www.cdc.gov/dpdx/malaria/index.html)

Fig. 6: The amoeboid appearance of P. vivax trophozoites in a thin smear. Image credit: CDC (https://www.cdc.gov/dpdx/malaria/index.html)

Fig. 7: Plasmodium vivax schizonts in a thin blood smear. On the right is the mature form, and on the left, the immature form. Image credit: Dr. mae Melvin/CDC

Note: P. ovale and P. vivax are not typically found in Ghana, more common in Southeast Asia.

Related Plasmodium falciparum content:

Refer to the blog on How to Identify Malaria Parasites Under the Microscopen Using Giemsa Stain:Giemsa Stained P. falciparum Stages

Plasmodium Species Guide: How to Identify Plasmodium falciparum Under the Microscope

P. falciparum

• Infects mature RBCs (cells don’t enlarge upon infection).

• Often shows double infection.

• Features:

• Multiple chromatin dots

• Nipple-like protrusions

• Ring and comma shapes

• Gametocyte is banana shaped

• Maurer’s dots

Fig.1: P. falciparum trophozoites in a thin blood smear, where Maurer’s clefts are seen. Maurer’s clefts are membranous, disc-shaped structures seen in Plasmodium falciparum-infected red blood cells (iRBCs), particularly during the trophozoite and schizont stages. They are parasite-induced membranous organelles within the host erythrocyte cytoplasm and are critical for trafficking virulence proteins, notably PfEMP1 (Plasmodium falciparum erythrocyte membrane protein 1), to the red cell surface. They appear as fine, stippled dots or delicate granulations in the cytoplasm of P. falciparum-infected RBCs. Maurer's clefts are best visualized via transmission electron microscopy (TEM). Image credit: CDC (https://www.cdc.gov/dpdx/malaria/index.html)

Fig.1b: Double infection of RBCs by P. falciparum trophozoites. Image by: Adwoa Agyapomaa

Fig.2: P. falciparum gametocytes in a thin blood smear. Ring-form trophozoites are  seen, as well as Maurer's clefts. Image credit: CDC (https://www.cdc.gov/dpdx/malaria/index.html)

Fig.3: A schizont of P. falciparum in a thin smear. Note the presence of trophozoites in the bottom right and top left of the image. Image credit: CDC (https://www.cdc.gov/dpdx/malaria/index.html)

Related Plasmodium falciparum content:

Refer to the blog on How to Identify Malaria Parasites Under the Microscopen Using Giemsa Stain:Giemsa Stained P. falciparum Stages