Loiasis + Onchocerciasis

Question 1

What is Loa loa?

Answer 1

A small (3-7 cm) filarial worm which is found in the subcutaneous tissues.

Question 2

The vectors of Loa loa are

Answer 2

…day-biting flies of the genus Chrysops, known as the tabanid fly (horse or deer fly).

Question 3

Loiasis symptoms

Answer 3

• Calabar swellings, which is a localized, tender, hot, soft tissue swellings occur due to hypersensitivity often near to a joint. These are produced in response to the passage of a worm and usually subside over a few days or weeks.
• There may also be more generalized urticaria and pruritus.
• they may also enter retro-orbital tissue, causing severe pain.

Question 4

Apart from DEC, what else is used in loiasis

Answer 4

Anti histamines and corticosteroids are given in allergic manifestations.
Ivermectin
Albendazole

Question 5

Onchocerciasis is the result of infection with

Answer 5

Onchocerca volvulus

Question 6

Onchocerciasis Infection is transmitted by

Answer 6

day-biting flies of the genus Simulium:
principally S. damnosum in West Africa,
S. neavei in East Africa, and S. metallicum in America.

Question 7

Clinical features of onchocerciasis

Answer 7

• Pruritus
• Lymphadenopathy “Hanging groin” in the inguinal and femoral regions.
• Subcutaneous nodules (onchocercomata) usually develop over bony prominences.
• Cause blindness later on. Initial visual symptoms range from itching, redness, photophobia, and blurred vision

Question 8

Onchocerciasis is associated with a latent period for what?

Answer 8

Development of larva into adults

Question 9

What is onchocercomata

Answer 9

Subcutaneous nodules

Question 10

Drug used in Onchocerciasis

Answer 10

Ivermectin, a macrocyclic lactone, used orally

Question 11

Ivermectin MOA

Answer 11

It intensifies GABA–mediated transmission of singals in peripheral nerves. In onchoceriasis it is microfilaricidal and does not kill adult worm.

Question 12

Adverse effects of ivermectin

Answer 12

Fatigue, dizziness, GI disturbance.
In onchoceriasis it cause Mazotti reaction:

Question 13

Mazotti reaction is ivermectin side-effects associated with

Answer 13

Fever, headache, dizziness, somonlence, weekness, rash, diarrhea, arthralagia, hypotension, lymphadenitis, peripheral edema due to killing of microfiliariae,

Question 14

How is Mazotti reaction treated?

Answer 14

With steroids

Question 15

Contraindication for ivermectin

Answer 15

• Other drugs that enhance GABA e.g Barbiturates, bnezodiazepines, valproaic acid.
• Pregnancy.
• Imparied blood brain barrier.
• Children under 5 years of age. 65

Question 16

The adult Loa loa develops in the…

Answer 16

Subcutaneous tissue