Strongyloides Stercoralis

Question 1

Name the super family of Strongyloides Stercoralis.

Answer 1

Rhabditoidea

Question 2

What is the common name for Strongyloides Stercoralis?

Answer 2

Threadworm

Question 3

What are the hosts for Strongyloides Stercoralis?

Answer 3

Dogs, foxes, cats

Question 4

Is Strongyloides Stercoralis zoonotic?

Answer 4

Yes!

Question 5

What are the characteristic features of adult Strongyloides Stercoralis?

Answer 5

Slender hair-like nematodes less than 1 cm in length.

Question 6

What are the characteristic features of the larvae and eggs of Strongyloides Stercoralis?

Answer 6

L1 about 600 micrometers, eggs with L1 are about 30x40 micrometers in size.

Question 7

What is this image showing?

Answer 7

Strongyloides Stercoralis eggs with larvae

Question 8

What is a unique feature typical of Strongyloides Stercoralis in this image?

Answer 8

Long esophagus that is 1/3 length of nematode

Question 9

Is the life cycle direct or indirect for Strongyloides Stercoralis?

Answer 9

Direct

Question 10

What are the two life cycle stages for Strongyloides Stercoralis?

Answer 10

Homogonic (parasitic) and Heterogonic (free-living)

Question 11

Explain the life cycles for Strongyloides Stercoralis.

Answer 11

Homogonic life cycle: Eggs containing L1 and liberated L1 are passed in feces -> in soil L1 develop to L3 -> infective L3 penetrate host skin or oral mucosa -> they migrate to the heart, through the lungs, up the trachea, swallowed, then migrate to intestines -> they develop to adult females (ONLY) and pathenogenesis takes place. PPP 10-14 days

Heterogonic life cycle: In favorable environmental conditions free-living larvae hatch from eggs and develop in soil directly to adult males and females -> females lay eggs which develop into free-living L3 -> infect host percutaneously and per os.

Question 12

Name two additional modes of transmission for Strongyloides Stercoralis.

Answer 12

Prenatal and Transmammary

Question 13

What are the sites of infection for Strongyloides Stercoralis?

Answer 13

Adults in small intestine. Larvae in skin.

Question 14

What are the pathogenesis and lesions for Strongyloides Stercoralis?

Answer 14

Adults cause inflammation in small intestine. Skin penetration by L3 causes erythematous reaction

Question 15

List the clinical signs associated with infection caused by Strongyloides Stercoralis.

Answer 15

Diarrhea, anorexia, weight loss, urticaria

Question 16

How is Strongyloides Stercoralis diagnosed?

Answer 16

L1 and eggs with L1 in fecal flotation. L1 recovered with the Baermann technique from fresh feces

Question 17

What is the treatment and prevention for Strongyloides Stercoralis?

Answer 17

Regular treatments with anthelmintics

Question 18

Who is at highest risk for zoonotic infection caused by Strongyloides Stercoralis?

Answer 18

Immunosuppressed humans

Question 19

The most likely cause of death in Ancylostoma Caninum-infected puppies that die of peracute hookworm disease during the second week of life is:

a. renal failure
b. diarrhea
c. anemia
d. pneumonia
e. hepatic failure

Answer 19

c. anemia