Tissue nematodes&filarial nematode infection

Question 1

LYMPHATIC nematodes

Answer 1

Wuchereria bancrofti
Brugia malayi Brugia timori

Question 2

SKIN/SUB CUTANEOUS nematodes

Answer 2

Loaloa [African eye worm]
Onchcerca volvulus [river blindness]
Dracunculus medinensis

Question 3

CONJUNCTIVA nematodes
Which is virtually nonpathogenic?

Answer 3

Loaloa
Serous cavity: Mansonella perstans
Mansonella ozzardi (They are virtually nonpathogenic)

Question 4

Periodicity examples

Answer 4

Nocturnal periodicity e.g. Wuchereria bancrofti
*Diurnal periodicity e.g. Loa loa
*Nonperiodic e.g. Onchocerca volvulus

Question 5

a classic sign of late-stage disease of LYMPHATIC FILARIASIS

Answer 5

Elephantiasis – painful, disfiguring swelling of the legs and genital organs – is a classic sign of late-stage disease

Question 6

Parasites with mosquito as Intermediate host

Answer 6

*Wuchereria bancrofti
*Brugia spp.
*Mansonella spp.
*Dirofi laria spp.

Question 7

Classical filariasis.

Answer 7

• blockage of lymph vessels and lymph nodes by the adult worms. The blockage could be due to mechanical factors or allergic inflammatory reaction to worm antigens and secretions.
• The affected lymph nodes and vessels are infiltrated with macrophages, eosionophils, lymphocytes, and plasma cells. The vessel walls get thickened and the lumen narrowed or occluded, leading to lymph stasis and dilatation of lymph vessels.
• The worms inside lymph nodes and vessels may cause granuloma formation, with subsequent scarring and even calcification.
• Inflammatory changes damage the valves in lymph vessels, further aggravating lymph stasis. Increased permeability of lymph vessel walls lead to leakage of protein-rich lymph into the tissues.
• This produces the typical hard pitting or brawny oedema of filariasis. Fibroblasts invade the oedematous tissues, laying down fibrous tissue, producing the non-pitting gross oedema of elephantiasis.
• Recurrent secondary bacterial infections cause further damage.

Question 8

Occult Filariasis and treatment

Answer 8

It occurs as a result of hypersensitivity reaction to microfilarial antigens, not directly due to lymphatic involvement.

Microfilariae are not found in blood, as they are destroyed by the tissues.

It is associated with a high level of serum IgE and filarial antibodies.

The condition responds to treatment with diethylcarbamazine (DEC), which acts on microfilariae and can cause Mazzotti reaction

Question 9

Which syndrome is a synonym for occult filariasis?

Answer 9

Meyers Kouwenaar syndrome

Question 10

The 2 major measures in prevention and control of filariasis are

Answer 10

i. Eradication of the vector mosquito
ii. Detection and treatment of carriers.

Question 11

L. loa causes

Answer 11

L. loa, causing loiasis, ‘fugitive swellings’ or ‘calabar swellings

Question 12

The microfilaria (L.Loa) are ingested by_______ during its blood meal.
How long do they take to develop?

Answer 12

Chrysops
10 days

Question 13

the ‘convoluted filaria’, or the ‘blinding filaria’ producing onchocerciasis or ‘river blindness’?

Answer 13

Onchocerca volvulus

Question 14

Dracunculus Medinensis aka

Answer 14

guinea worm