II.C - Parasitology | 30. Enterobius vermicularis, Ascaris lumbricoides, Toxocara canis, Trichinella spiralis

Question 1

I. Enterobius vermicularis - pinworm
1. What are the features of Enterobius vermicularis?

Answer 1

• Small roundworm, 1 cm
• Most common worm infection in temperate climate
• Primarily affects children 5–10 years of age

Question 2

I. Enterobius vermicularis - pinworm
2. What are the lifecycle and spread of Enterobius vermicularis?

Answer 2

Question 3

I. Enterobius vermicularis - pinworm
3. What are the symptoms of Enterobius vermicularis ?

Answer 3

• Asymptomatic mostly
• Disturbed sleeping, itching of the perianal area
• Worm might be found in faeces

Question 4

I. Enterobius vermicularis - pinworm
4. What is the diagnosis for Enterobius vermicularis - pinworm?

Answer 4

Question 5

I. Enterobius vermicularis - pinworm
5. What is the treatment for Enterobius vermicularis - pinworm?

Answer 5

mebendazole

Question 6

II. Ascaris lumbricoides - giant roundworm
1. What are the features of Ascaris lumbricoides?

Answer 6

• 20 cm roundworm
• Most common helminth infection worldwide

(mainly affects children in tropical countries with low standards of hygiene)

Question 7

II. Ascaris lumbricoides - giant roundworm
2. What is the mode of transmission of Ascaris lumbricoides?

Answer 7

• Fecal-oral, especially raw vegetables contaminated by human waste
• Geohelminth – matures in soil

Question 8

II. Ascaris lumbricoides - giant roundworm
3. What are the clinical features of Ascaris lumbricoides?

Answer 8

Question 9

II. Ascaris lumbricoides - giant roundworm
4. What is the diagnosis for Ascaris lumbricoides?

Answer 9

Microscopy of stool sample for eggs

Question 10

II. Ascaris lumbricoides - giant roundworm
5. What is the treatment for Ascaris lumbricoides - giant roundworm?

Answer 10

mebendazole

Question 11

III. Toxocara canis - dog roundworm
1. How does Toxocara canis spread?

Answer 11

1. Fecal-oral: ingestion of Toxocara eggs from an infected dog feces
   - eg. from playground sand or garden soil
2. Larva will migrate in human body

Question 12

III. Toxocara canis - dog roundworm
2. What are the 2 forms of Toxocara canis?

Answer 12

1. VISCERAL TOXOCARIASIS (visceral larva migrans)
2. OCULAR TOXOCARIASIS (ocular larva migrans)

Question 13

III. Toxocara canis - dog roundworm
3. What are the features of VISCERAL TOXOCARIASIS (visceral larva migrans)?

Answer 13

• Larvae migrating through the intestinal wall into the blood, reaches organs
• Fever and flu-like symptoms – and organ specific symptoms
• eg. Liver, lung, brain

Question 14

III. Toxocara canis - dog roundworm
4. What are the features of OCULAR TOXOCARIASIS (ocular larva migrans)?

Answer 14

• caused by larvae migrating into the eye
• Unilateral loss of vision

Question 15

III. Toxocara canis - dog roundworm
5. What is the diagnosis for OCULAR TOXOCARIASIS (ocular larva migrans)?

Answer 15

Serology

Question 16

III. Toxocara canis - dog roundworm
6. What is the treatment for OCULAR TOXOCARIASIS (ocular larva migrans)?

Answer 16

mebendazole

Question 17

IV. Trichinella spiralis
1/ How does Trichinella spirali spread?

Answer 17

Spread: eating undercooked pork and boar meat
=> Larvae will migrate and encyst in human muscle

Question 18

IV. Trichinella spiralis
1/ How does Trichinella spirali spread?

Answer 18

Spread: eating undercooked pork and boar meat

Question 19

IV. Trichinella spiralis
2. What are the clinical features of . Trichinella spiralis?

Answer 19

• Intestinal phase : allergic reaction, abdominal pain, diarrhea, vomiting
• Muscle phase: muscle swelling, weakness, fever

Question 20

IV. Trichinella spiralis
3. What is the diagnosis for Trichinella spiralis?

Answer 20

Serology

Question 21

IV. Trichinella spiralis
4. What is the treatment for Trichinella spiralis?

Answer 21

mebendazole