Tissue Nematodes Flashcards
(20 cards)
Name three Filarial Nematodes that are classified as causing Subcutaneous infections.
Loa loa, Mansonella streptocerca, Onchocerca volvulus
Which Filarial Nematode is known as the “African eye worm” and causes “Calabar/Fugitive swelling”?
Loa loa
Which Filarial Nematode causes “river blindness” and dermatitis?
Onchocerca volvulus
Which Filarial Nematodes are found in the Serous cavity and are considered non-pathogenic?
Mansonella ozzardi, Mansonella perstans
Name the Filarial Nematodes primarily associated with Lymphatic filariasis.
Wuchereria bancrofti, Brugia malayi, Brugia timori
Entry of infective larvae to the 1st appearance of microfilariae (MF) in the blood.
Prepatent period
Entry of infective larvae to the onset of clinical manifestations and how long?
Incubation period, 8-16 months
What is the general requirement for Filarial Nematodes to complete their life cycle?
They require an arthropod as an intermediate host.
How are microfilariae generally released into the human host?
When an infected arthropod takes a blood meal, the microfilariae are released into the human host.
What is the primary method of laboratory diagnosis for most filarial parasites?
Examining Giemsa-stained thick & thin blood smears.
What is an exception to the usual blood smear diagnosis for Onchocerca volvulus?
Skin scraping from nodules.
What specific blood collection timing is crucial for detecting microfilariae of species like Wuchereria bancrofti and Brugia spp.?
Nocturnal (10 pm - 2 am) due to their nocturnal periodicity.
common laboratory diagnostic tests for filarial infections (besides blood smears).
ICT filaria, Clinical diagnosis
, Antigen detection
,Molecular diagnosis
What are some clinical situations where a filaria blood film investigation is indicated?
Investigation of recurrent (particularly nocturnal) fever; Unexplained chronic edema, chyluria, chylous effusions in a patient from an endemic area.
When collecting blood for a filaria blood film, what specific conditions should be met regarding the patient and collection time?
Blood must be collected when the patient is febrile (if applicable), or at night time, and the blood film immediately prepared.
Presence of microfilariae (MF) in the blood, but no clinical signs and symptoms. May progress to acute and chronic stage. Men often have higher MF rate than women
Asymptomatic stage
Recurrent fever, Lymphadenitis, Lymphangitis, Funiculitis, Epididymitis, Orchitis.
Acute stage
Develops 5-15 years after the death of adult worms, which form granulomas that block the lymphatic channels.
Chronic stage
Are microfilariae usually present in the blood during the Chronic stage of lymphatic filariasis?
No, microfilariae are usually absent in the blood.
Name four key clinical manifestations of the Chronic stage of lymphatic filariasis.
Hydrocoele, Lymphedema, Elephantiasis, Chyluria.
