Strongyloides stercoralis, S. westeri, S. ramsoni, S. papillosus

Question 1

What Strongyloides species infect human, cat, dog and monkeys?

Answer 1

Strongyloides stercoralis

This species is known for its ability to cause chronic infections in humans.

Question 2

Describe the egg of Strongyloides stercoralis.

Answer 2

Small, oval, 2 thin shells, embryonated (L1), transparent

The eggs are characterized by their embryonated state when passed.

Question 3

What special feature allows Strongyloides stercoralis to cause autoinfection?

Answer 3

L1 hatch from the eggs already in the intestine and develop to L3

• L3 begin a migration from intestines to skin and then return to GIT. It can be a chronic infection (up to 40 years in humans). Females are also able to interrupt egg production temporarily and start again later.

This process allows the larvae to migrate from the intestines to the skin and back.

Question 4

List some clinical signs associated with Strongyloides stercoralis infection.

Answer 4

• Mild diarrhea
• Loss of appetite
• Loss of weight
• Weakness
• Dehydration
• Fetal for puppies

Question 5

What are the pathogenesis symptoms of Strongyloides stercoralis?

Answer 5

Frequently asymptomatic

• Gastrointestinal symptoms - abdominal pain, diarrhoea
• Pulmonary symptoms - coughing, nasal discharge
• Dermatologic manifestations - urticarial rashes in buttocks and waist areas
• Subcutaneous lesions - from worms

lactogenic transmission

Question 6

True or False: Strongyloides stercoralis can infect both dogs and humans.

Answer 6

True

This zoonotic potential makes it important in veterinary and human medicine.

Question 7

What is the primary definitive host for Strongyloides westeri?

Answer 7

Horse and donkeys

This species predominantly affects equines.

Question 8

Describe the morphology of Strongyloides westeri.

Answer 8

Threadworms, long and hair-like

Adults grow to be 8-9 mm in length.

Question 9

How does Strongyloides westeri infect its host?

Answer 9

By oral/skin

• Larvae mature to adult worms in the small intestine.

The larvae can enter the host through the skin or be ingested.

Question 10

What are some clinical signs of Strongyloides westeri?

Answer 10

• Bleeding
• Respiratory problems
• Inflammation & Rashes of skin
• Diarrhea
• Weakness
• Weight loss
• Failure to grow and thrive in young

Question 11

What is the primary host for Strongyloides ransomi?

Answer 11

Pigs

It is the main parasite affecting suckling piglets.

Question 12

What transmission method is associated with Strongyloides ransomi?

Answer 12

Transmammary transmission

This allows the parasite to be passed from mother to offspring during nursing.

Question 13

What are some clinical signs of Strongyloides ransomi?

Answer 13

• Coughing
• Stiffness
• Pain
• Vomiting
• Bloody diarrhea
• High mortality

Question 14

Describe the egg of Strongyloides ransomi.

Answer 14

Small, oval, symmetrical, 2 thin shells, embryonated (L1), transparent

Question 15

In which geographical areas is Strongyloides ransomi predominantly found?

Answer 15

Warm climates

This species thrives in environments with higher temperatures.

Question 16

Describe the egg of Strongyloides papillosus.

Answer 16

Small, oval, symmetrical, 2 thin shells, embryonated with L1, transparent

Question 17

Geography of Strongyloides stercoralis

Answer 17

Tropical and subtropical areas