Parasite
Loa loa
African eye worm with Calabar swellings
LOH-uh LOH-uh
High-yield clue
Adult worm crossing the subconjunctiva plus transient Calabar swellings; microfilariae show diurnal periodicity matching the daytime-biting deerfly.
Overview
A filarial nematode transmitted by Chrysops deerflies (mango flies) whose adults migrate through subcutaneous tissue, the classic 'eye worm' of loiasis.
Classification
- Nematode (filarial worm)
- Adults migrate in subcutaneous tissue
- Sheathed microfilariae
- Transmitted by Chrysops deerfly
Lab & identification clues
- Sheathed microfilariae on midday (diurnal) blood smear
- Adult worm visible crossing the eye
- Giemsa-stained blood smear vocabulary
Associations
- Chrysops (deer/mango fly) vector, daytime biting
- Diurnal periodicity of microfilariae
- Calabar swellings (transient subcutaneous edema)
- West/Central African rainforest distribution
Commonly confused with
- Wuchereria bancrofti
- Onchocerca volvulus
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.