TISSUE NEMATODES - Onchocerca volvulus

Question 1

adult stage of o. volvulus causes the formation of

Answer 1

subcutaneous nodules

Question 2

microfilariae is found in

Answer 2

subcutaneous tissue
lymphatic tissues

Question 3

migrates –> causing eye and skin related problem

Answer 3

microfilariae

Question 4

how to diagnose?

Answer 4

skin biopsy

Question 5

vector

Answer 5

simulian black fly

Question 6

characterized by CUTANEOUS and OCULAR pathology that occurs after the invasion and death of microfilariae in the skin and eye

Answer 6

onchocerciasis

Question 7

subcutaneous nodule is also known as

Answer 7

onchocercoma

Question 8

river blindness is primarily caused by

Answer 8

• inflammatory mediators released by dead microfilaria
• wolbachia bacteria

Question 9

due to allergic reaction towards the migrating microfilariae = scratch = light lichenification

Answer 9

pruritic reaction

Question 10

pruritic reaction: scratch –> skin thickes

Answer 10

light lichenification

Question 11

light lichenification causes skin to suffer from

Answer 11

hyperpigmentation
depigmentation

Question 12

intermittent dermatitis may progress to

Answer 12

hyperpigmentation
depigmentation (leopard skin)
loss of elasticity (hanging groin)

Question 13

morphology of female adult worm

Answer 13

2 uteri
intestine
cuticle

Question 14

gold standard method of diagnosis

Answer 14

skin snips

Question 15

describe microfilariae of onchocercus volvulus

Answer 15

cephalic space: 2:1 longer than wide
body nuclei: crowded
tail does not have any nucleus
unsheated

Question 16

drug of choice

Answer 16

ivermectin (kills larva) + doxycycline (kills wolbachia)

Question 17

old drug but not recommended anymore as it accelerates river blindness

Answer 17

diethylcarbamazine