Introduction to Parasites, Nematodes and Bugs

Question 1

Physical characteristics of nematodes (3):

Answer 1

• Smooth borders.
• Even shape with tapered ends.
• Unpigmented.

Question 2

Most common helminth infection:

Answer 2

Ascaris lumbricoides (roundworm).

Question 3

Ascaris lumbricoides clinical manifestations (3):

Answer 3

• Most are asymptomatic.
• GI: mild-moderate discomfort, symptoms of obstruction.
• Pulmonary: Loeffler’s syndrome (eosinophilic pneumonitis).

Question 4

Ascaris lumbricoides treatment (2):

Answer 4

• Mebendazole.

- Albendazole.

Question 5

Necator americanus/ancyclostoma duodenale clinical manifestations (4):

Answer 5

Hookworms

• Pulmonary: Loeffler’s syndrome.
• GI: Mild abdominal pain.
• Hematologic: signs of anemia.
• Skin: localized rash at entry site.

Question 6

Necator americanus/ancyclostoma duodenale diagnosis:

Answer 6

Hookworm eggs on microscopic exams.

- Must be examined within 1-2 hours or they can hatch.

Question 7

Necator americanus/ancyclostoma duodenale treatment (3):

Answer 7

• Mebendazole.
• Albendazole.
• Ivermectin.

Question 8

Strongyloides stercoralis clinical manifestations (4):

Answer 8

• 50% of patients are asymptomatic.
• GI: stomach pain, diarrhea, indigestion, cramping.
• Pulmonary: Loeffler’s syndrome.
• Skin: Larva currens, rash moves rapidly.

Question 9

Strongyloides stercoralis clinical hyperinfection (3):

Answer 9

• Occurs in those who are immunosuppressed.
• Worms migrate and invade organs.
• Can lead to life threatening gram negative sepsis.

Question 10

Strongyloides stercoralis treatment (2):

Answer 10

• Albendazole.

- Ivermectin.

Question 11

Toxocariasis clinical manifestations (5):

Answer 11

• Asthma-like attacks.
• N/V, abdominal discomfort.
• Rashes.
• Liver enlargement.
• Visual loss due to larvae entering the eye.

Question 12

Toxocariasis treatment (2):

Answer 12

• Albendazole.

- Mebendazole.

Question 13

Enterobius vermicularis transmission:

Answer 13

Fecal-oral route.

Question 14

Enterobius vermicularis symptoms:

Answer 14

Intense itching around the anus, especially at night.

Question 15

Enterobius vermicularis diagnosis (2):

Answer 15

• Scotch tape test.

- Direct visualization.

Question 16

Enterobius vermicularis treatment (4):

Answer 16

• Mebendazole.
• Albendazole.
• Pyrantel pamoate (young children).
• Must treat WHOLE family.

Question 17

Trichuris trichiura clinical manifestations (3):

Answer 17

• Lower abd pain, abd distention and chronic diarrhea.
• Colitis mimicking IBD +/- bleeding.
• Rectal prolapse.

Question 18

Trichuris trichiura diagnosis:

Answer 18

Characteristic barrel-shaped eggs.

Question 19

Trichuris trichiura treatment (3):

Answer 19

• Ivermectin.
• Albendazole.
• Mebendazole.

Question 20

Trichinellosis transmission:

Answer 20

Undercooked pig, wild boars, bears, arctic walruses and seals.

Question 21

Trichinellosis intestinal stage manifestations:

Answer 21

1-7 days after infection:

- Fevers, N/V, abd cramping, diarrhea, malaise, headache.

Question 22

Trichinellosis muscle invasion stage manifestations (4):

Answer 22

1-8 weeks after infection:

• Muscle pain and tenderness.
• Facial/periorbital edema.
• Splinter hemorrhages in nail beds.
• Diffuse rash.

Question 23

Trichinellosis late stage manifestations (3):

Answer 23

1-2 months after infection:

• Cardiac: CHF from myocarditis.
• Neurologic: meningitis, encephalitis.
• Vague muscle pains and malaise (may persist for months).

Question 24

Trichinellosis diagnosis (4):

Answer 24

• History.
• Labs: eosinophilia, elevated CPK, elevated AST.
• ELISA test.
• Muscle biopsy (definitive test).

Question 25

Trichinellosis treatment:

Answer 25

Severe cases:
- Steroids + mebendazole.
Mild cases:
- antipyretics.

Question 26

Angiostrongyliasis transmission:

Answer 26

Snails and slugs.

Question 27

A. cantonensis (3):

Answer 27

• Eosinophilic meningitis.
• Distinctive paresthesias.
• No treatment.

Question 28

A. costaricensis (2):

Answer 28

• Fever, vomiting, abd pain, RLQ mass.

- High blood eosinophil count.

Question 29

Scabies transmission:

Answer 29

Direct skin-skin contact, also from fabrics.

Question 30

Scabies crustosia (4):

Answer 30

• Hyperinfestation usually in immunodeficient patients.
• Highly contagious.
• Itching may be absent.
• Tx: Ivermectin 1-2 oral doses.

Question 31

Scabies diagnosis (4):

Answer 31

• Intense itching especially at night.
• 2+ people in same household with nocturnal itching.
• Scraping of lesions w/ mineral oil.
• Ink test.

Question 32

Scabies treatment (4):

Answer 32

• Don’t treat without diagnosis.
• Treat ALL family members simultaneously.
• Permethrin 5% neck down overnight.
• Thorough washing of clothes and bedding.

Question 33

Head louse transmission:

Answer 33

Physical contact, hats, brushes.

Question 34

Head louse manifestation:

Answer 34

Itchy scalp, particularly back of neck.

Question 35

Head louse diagnosis:

Answer 35

Direct visualization.

Question 36

Head louse treatment (4):

Answer 36

• Permethrin
• Ivermectin
• Malathion
• Pyrethrins

Question 37

Body louse transmission:

Answer 37

Person-person contact.

Question 38

Body louse manifestations:

Answer 38

Itchy red pin-point lesions.

Question 39

Body louse treatment (2):

Answer 39

• Permethrin

- Malathion

Question 40

Crab louse transmission:

Answer 40

Sexual contact.

Question 41

Crab louse diagnosis:

Answer 41

Direct visualization.

Question 42

Crab louse treatment (2):

Answer 42

• Permethrin

- Malathion