Parasite
Babesia microti
Tick-borne intraerythrocytic piroplasm
buh-BEE-zhuh my-KROH-tee
High-yield clue
Ring forms plus the rare Maltese-cross tetrad inside red cells, without malarial pigment, is the core exam clue.
Overview
An intraerythrocytic protozoan parasite (piroplasm) transmitted by Ixodes ticks that infects red blood cells and is a classic study contrast to malaria. It matters because it shares a vector and geography with Lyme disease.
Classification
- Protozoa
- Apicomplexa
- Piroplasmida
- Intraerythrocytic parasite
Lab & identification clues
- Giemsa-stained thin/thick blood smear vocabulary
- Maltese-cross tetrad of merozoites
- Ring forms lacking hemozoin pigment
- PCR confirmation vocabulary
Associations
- Ixodes scapularis (blacklegged tick) vector
- White-footed mouse (Peromyscus) reservoir
- Northeastern/upper-Midwest US epidemiology
- Co-infection with Lyme disease study link
Commonly confused with
- Plasmodium falciparum
- Plasmodium species ring forms
Your notes
Original student-study summary. Sources checked: OpenStax Microbiology 2e, NCBI Bookshelf Medical Microbiology, and CDC topic pages where applicable; reviewed 2026-06. Educational only; no diagnosis, treatment, dosing, or specimen-handling guidance.