Micro - Parasitology (Worms & Parasite hints)

Question 1

What is another name for roundworms?

Answer 1

Nematodes

Question 2

What are 4 examples of intestinal Nematodes? Where applicable, give common name in addition to genus species names.

Answer 2

(1) Enterobius vermicularis (pinworm) (2) Ascaris lumbricoides (giant roundworm) (3) Strongyloides stercoralis (4) Ancylostoma dudoenale, Necator americanus (hookworms)

Question 3

What is the genus & species for pinworm? How is it transmitted?

Answer 3

Enterobius vermicularis; Fecal-oral

Question 4

What disease/symptoms does Enterobius vermicularis (pinworm) cause? How is it diagnosed? How is it treated?

Answer 4

Intestinal infection causing anal pruritus (diagnosed via the Scotch Tape test); Bendazoles or pyrantel pamoate; Think: “worms are BENDy; treat with meBENDazole”

Question 5

What is the genus & species for giant roundworm? How is it transmitted? What can be seen under microscope?

Answer 5

Ascaris lumbricoides; Fecal-oral, eggs visible in feces under microscope

Question 6

What disease is caused by Ascaris lumbricoides (giant roundworm)? How is it treated?

Answer 6

Intestinal infection; Bendazoles or pyrantel pamoate

Question 7

How is Strongyloides stercoralis transmitted?

Answer 7

Larvae in soil penetrate the skin

Question 8

What disease/symptoms does Strongyloides stercoralis cause? How is it treated?

Answer 8

Intestinal infection causing vomiting, diarrhea, anemia; Ivermectin or albendazole

Question 9

What are 2 genuses and species for hookworms? How are they transmitted?

Answer 9

Ancylostoma dudodenale, Necator americanus; Larvae penetrate skin

Question 10

What disease do hookworms (Ancylostoma duodenale & Necator americanus) cause? How is it treated?

Answer 10

Intestinal infection causing anemia by sucking blood from intestinal walls; Bendazoles or pyrantel pamoate

Question 11

What are 4 examples of tissue Nematodes?

Answer 11

(1) Onchocerca volvulus (2) Loa loa (3) Wuchereria bancrofti (4) Toxocara canis

Question 12

How is Onchocerca volvulus transmitted? What disease does it cause? What is a possible side reaction? How is it treated?

Answer 12

Female blackfly bite; Tissue disease - Hyperpigmented skin and river blindness (Think: “BLACK flies, BLACK skin nodules, BLACK sight”); Allergic reaction to microfilaria possible; Ivermectin (Think: “IVERmectin for rIVER blindness”)

Question 13

How is Loa loa transmitted? What disease does it cause? How is it treated?

Answer 13

Deer fly, horse fly, mango fly; Tissue disease - Swelling in skin, worm in conjuctiva; Diethylcarbamazine

Question 14

How is Wuchereria bancrofti transmitted? How long after the bite does it take to become symptomatic?

Answer 14

Female mosquito; takes 9 mo-1 yr after bite to become symptomatic

Question 15

What disease does Wuchereria bancrofti cause? How is it treated?

Answer 15

Tissue disease - Blocks lymphatic vessels: elephantiasis; Diethylcarabamazine

Question 16

How is Toxocara canis transmitted? What disease does it cause? How is it treated?

Answer 16

Fecal-oral; Tissue disease - Visceral larva migrans; Albendazole or mebendazole

Question 17

What are the 3 main routes for infection by Nematodes. Which Nematodes take which route?

Answer 17

(1) Ingested - Enterobius, Ascaris, Trichinella (Think: “you’ll get isck if you EAT these!”) (2) Cutaneous - Strongyloides, Ancylostoma, Necator (Think: “these get into your feet from the SANd”) (3) Bites - Loa loa, Onchocerca volvulus, Wuchereria bancrofti (Think: “lay LOW to avoid getting bites”)

Question 18

What is another name for tapeworms? What are 3 examples?

Answer 18

Cestodes; (1) Taenia solium (2) Diphyllobothrium latum (3) Echinococcus granulosus

Question 19

How is Taenia solium transmitted? What disease(s) does it cause? What is/are its treatment(s)?

Answer 19

(1) Ingestion of larvae encysted in undercooked pork –> Intestinal infection –> Tx: Praziquantel (2) Ingestion of eggs –> Cysticercosis, neurocysticercosis –> Tx: Praziquantel; Albendazole for neurocysticercosis

Question 20

How is Diphyllobothrium latum transmitted? What disease does it cause? How is it treated?

Answer 20

Ingestion of larvae from raw freshwater fish; Vitamin B12 deficiency (tapeworm competes for B12 in intestine) –> anemia; Praziquantel

Question 21

How is Echinococcus granulosus transmitted? What disease does it cause? How is this managed clinically, and why? How is it treated?

Answer 21

Ingestion of eggs from dog feces; Hydatid cysts in liver, causing anaphylaxis if antigens released (surgeons preinject with ethanol to kill cysts before removal); -bendazoles

Question 22

What is another name for flukes? What are 2 examples?

Answer 22

Trematodes; (1) Schistosoma (2) Clonorchis sinensis

Question 23

How is Schistosoma transmitted? What disease does it cause? How is it treated?

Answer 23

Snails are host, cercariae penetrate skin of humans; Liver and spleen granulomas, fibrosis, and inflammation; Praziquantel

Question 24

What species of Schistosoma poses a particularly important risk following chronic infection? What is that risk?

Answer 24

Chronic infection with S. haematobium can lead to squamous cell carcinoma of bladder

Question 25

How is Clonorchis sinensis transmitted? What disease does it cause? How is it treated?

Answer 25

Undercooked fish; Biliary tract inflammation –> pigmented gallstones; Praziquantel

Question 26

Again, what disease does Clonorchis sinensis cause? With what kind of risk is it associated?

Answer 26

Biliary tract inflammation –> pigmented gallstones; Associated with cholangiocarcinoma

Question 27

If your patient has brain cysts and seizures, which parasite is most likely?

Answer 27

Taenia solium (cysticercosis)

Question 28

If your patient has liver (hydatid) cysts, which parasite is most likely?

Answer 28

Echinococcus granulosus

Question 29

If your patient has Vitamin B12 deficiency, which parasite is most likely?

Answer 29

Diphyllobothrium latum

Question 30

If your patient has biliary tract disease and/or cholangiocarcinoma, which parasite is most likely?

Answer 30

Clonorchis sinensis

Question 31

If your patient has portal hypertension, which parasite(s) is (are) most likely?

Answer 31

Schistosoma mansoni, Schistosoma japonicum

Question 32

If your patient has hematuria and/or bladder cancer, which parasite is most likely?

Answer 32

Schistosoma haematobium

Question 33

If your patient has microcytic anemia, which parasite(s) is (are) most likely?

Answer 33

(Hookworms) Ancylostoma, Necator

Question 34

If your patient has perianal pruritus, which parasite is most likely?

Answer 34

Enterobius