Appearance:

Like malaria, Babesia species can be seen both intracellularly and extracellularly and visualed with the Giemsa stain. Babesia parasites appear as ring forms in the red blood cell with variable morphology.¹

Note: Tetrad of rings may appear as a “maltese cross”.¹

Organisms:

The Babesia microti parasite is carried by the Ixodes scapularis tick.¹ Humans are incidental dead-end hosts of Babesia.

References:

1. Keohane EM. Extrinsic defects leading to increased erythrocyte destruction – nonimmune causes. In: Rodak’s hematology clinical applications and principles. 5th ed. St. Louis, Missouri: Saunders; 2015. p. 394-410.