Parasitology-Methods

Question 1

Direct Examination - Stool:

• Number/frequency
• Components (3)

Answer 1

3 specimens >24 hours apart (required to exclude)

• Fresh specimen (<1 hr; if >1 hr use formalin/alcohol)
• Concentration with exam of “wet prep”
• Permanent preparation

Question 2

Protozoa that are likely to missed with routine O&P stains? (5)
*What stains do these require

Answer 2

• Cryptosporidium spp.
• Cyclospora cayetanesis
• Cystoisospora (formerly Isospora) belli

*Modified Acid-Fast (Kinyoun, DMSO, auramine-O) or Modified Safranin Stains

Question 3

Direct Examination - Duodenal contents:

-Detection of what? (2)

Answer 3

• Giardia intestinalis

- Strogyloides stercoralis

Question 4

Direct Examination - Cellphane tape preparation.

-Detects?

Answer 4

Enterobius vermicularis (Pinworm)

Question 5

Direct Examination - Blood:

-Erythrocytes (2)

Answer 5

• Plasmodium spp.

- Babesia spp.

Question 6

Direct Examination - Blood:

-Leukocytes (2)

Answer 6

• Leishmania spp. (Amastigotes)

- Toxoplasma gondii (Tachyzoites)

Question 7

Direct Examination - Whole Blood/Plasma:

-Extracellular (5)

Answer 7

• Trypanosoma spp.
• Microfilariae
• Wuchereria bancrofti
• Brugia malayi
• Loa loa
• Mansonella spp.

Question 8

Direct Examination - Respiratory:

-Detects (3)

Answer 8

• Paragoniumus spp. eggs (lung fluke)
• Strongyloides stercoralis larvae
• Echinoccus spp. hooklets (ruptured cysts)

Question 9

Direct Examination - Serology:

• Role
• Screening
• Diagnosis

Answer 9

• Limited role
• Prenatal/Postnatal toxoplasmosis screening
• Dx of Amebic liver abscess d/t E. histolytica

Question 10

Parasites are usually not cultured, what are the exceptions?

Answer 10

• Acanthamoeba spp.
• Naegleria fowleri
• Trichomonas vaginalis
• Leishmania spp. (less common)

Question 11

Parasite culture media:

-Free living amoeba (Acanthamoeba/Naegleria fowleri)

Answer 11

Tap water agar on bed of E. coli (for nutrient source)

Question 12

Parasite culture media:

-Leishmania spp. and Trypanosoma spp.

Answer 12

Novy-MacNeal-Nicolle (NNN) media

Question 13

Parasite culture media:

-Trichomonas vaginalis

Answer 13

Diamond media

Question 14

Most common parasites by body site:

-Bone Marrow (2)

Answer 14

• Leishmania spp.

- Plasmodium spp.

Question 15

Most common parasites by body site:

-CNS (8)

Answer 15

• Taenia solium
• Echinococcus spp.
• Naegleria fowleri
• Acanthamoeba spp.
• Balamuthia mandrillaris
• Toxoplasma gondii
• Microsporidia
• Trypanosoma burcei

Question 16

Most common parasites by body site:

-Cutaneous Ulcer (2)

Answer 16

• Leishmania spp.

- Acanthamoeba spp.

Question 17

Most common parasites by body site:

-Liver, Spleen (8)

Answer 17

• Echinococcus spp.
• Entamoeba histolytica
• Leishmania spp.
• Microsporidia
• Schistosoma mansoni
• Schistosoma japonicum (eggs only)
• Fasciola hepatica
• Clonarchis sinensis

Question 18

Most common parasites by body site:

-Muscle (4)

Answer 18

• Trichinella spp.
• Taenia solium (cysticerci)
• Trypanosoma cruzi
• Microsporidia

Question 19

Most common parasites by body site:

-Lung (6)

Answer 19

• Crytosporidium spp.
• Echinococcus spp.
• Paragoniums spp.
• Toxoplasma gondii
• Strongyloides stercolis (larvae)
• Microsporidia

Question 20

Most common parasites by body site:

-Skin/Subcutaneous tissue (5)

Answer 20

• Leishmania spp.
• Onchocerca volvulus
• Microfilariae
• Sarcoptes scabei
• Loa Loa (adult worm)

Question 21

Most common parasites by body site:

-Urogenital system (4)

Answer 21

• Trichomonas vaginalis
• Schistosoma spp. (eggs only)
• Microsporidia
• Microfilariae

Question 22

Most common parasites by body site:

-Eyes (5)

Answer 22

• Acanthamoeba spp.
• Toxoplasma gondii
• Loa loa
• Onchocerca volvulus
• Microsporidia

Question 23

T/F: Molecular methods for parasitology identification is limited.

Answer 23

True