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
Frequently asked questions
What is Babesia microti?
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.
What are the lab clues for Babesia microti?
Lab clues for Babesia microti include Giemsa-stained thin/thick blood smear vocabulary, Maltese-cross tetrad of merozoites, Ring forms lacking hemozoin pigment, and PCR confirmation vocabulary.
What is Babesia microti commonly confused with?
Babesia microti is commonly confused with Plasmodium falciparum and Plasmodium species ring forms.
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.