Filarial Worms Overview Quiz

What species are responsible for transmitting Loa loa?

What is a distinguishing feature of the microfilariae of Loa loa compared to Brugia malayi and Brugia timori?

During which time of day are Loa loa microfilariae typically detected in peripheral blood?

Which of the following symptoms is associated with the migration of adult Loa loa worms?

What is the typical length of microfilariae from Brugia malayi and Brugia timori?

Which clinical feature is characteristic of Calabar swellings?

What clinical presentation can occur if Loa loa migrates through the eye?

Which diagnostic method is preferred for detecting microfilariae in a patient suspected of having a filarial infection?

Brugia Malayi & Brugia Timori

Cause lymphatic filariasis in Southeast Asia
Pathology and life cycle similar to W. bancrofti
Vector: Mansonia species

Morphology

Microfilariae are 177-230 µm long
Tapered tails with two terminal nuclei
Have a sheath

Loa Loa

Also known as the African eye worm
Filarial nematode found in rainforests of West and Central Africa
Transmitted by Chrysops species

Loa Loa Morphology

Microfilariae are 250-300 µm long
Have a sheath
Curved tails with numerous nuclei
Diurnal periodicity (12-2 pm)

Wuchereria

Adult Wuchereria lives in subcutaneous tissues; sometimes in the subconjunctival tissue
Life cycle similar to W. bancrofti

Clinical Presentation

Adult worm migration through subcutaneous tissues is usually painless
Noticed only when worm passes over bridge of nose or through conjunctiva of eye
Eye involvement may lead to irritation, congestion and pain (15-20 minutes)

Calabar Swellings

Migratory, localized subcutaneous edema
Can appear anywhere on the body, but most common on the extremities
Develops quickly, may be preceded by localized pain, itching, and hives

Lab Diagnosis

Detecting microfilariae in peripheral blood samples (daytime)
Thin blood smear, thick blood smear, or ideally a concentration technique (Knott or nucleopore filter)

Test your knowledge on Brugia malayi, Brugia timori, and Loa loa, including their morphology, life cycles, and clinical presentations. This quiz covers essential information about lymphatic filariasis and the vectors involved in their transmission. Prepare to dive into the fascinating world of filarial nematodes and their impact on human health!