Micro 30 - Helminths and Ectoparasites Flashcards Preview

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Flashcards in Micro 30 - Helminths and Ectoparasites Deck (52)
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1

What is another name for Enterobius vermicularis?

Pinworm.

2

What is the most common clinical presentation of Enterobius vermicularis infection and why?

Female worm lays eggs at anus at night, causing anal pruritis.

3

How is Enterobius vermicularis diagnosed?

Scotch tape test. Put scotch tape at night on the anus, remove it in the morning to find eggs and sometimes the worm.

4

What is the treatment for Enterobius vermicularis?

Albendazole.
Mebendazole.
Pyrantel pamoate.

5

What is second most common helminthic infection in the US?

Ascaris lumbricoides.

6

What is the pathophysiology of ascaris lumbricoides?

Female worm releases 200k eggs per day which pass through the stool, if they land in favorable environment, they can become infectious in 2-6 weeks. The ingested eggs hatch in the small intestine and release larvae. They the penetrate bowels, traveling to the lungs, migrate up the trachea to oropharynx to be swallowed. Worms mature in intestine.

7

What is another pathology that ascaris lumbricoides can cause?

Loffler eosinophilic pnemonitis.

8

What is the treatment for Ascaris lumbricoides infection?

Mebendazole, Albendazole, or Pyrantel pamoate.

9

What is the route of infection for Trichinella spiralis?

Consuming undercooked meat, especially wild game such as bear meat.

10

What are the clinical symptoms of Trichinella spiralis?

Larvae migrate from GI tract to muscles, causing myositis, fever, eosinophilia, and even periorbital edema.

11

Which three helminths enter the body through the fecal oral route?

[E.A.T.]

Enterobius.
Ascaris.
Trichinella.

12

How does one get infected with Strongyloides stercoralis?

Infected larvae live in soil and then penetrate skin. It then follows the same strange mechanism like ascariasis: goes through the bloodstream, penetrates the alveoli and then you cough it up and swallow it.

13

What is the treatment for Strongyloides stercoralis?

1. Ivermectin.
2. Mebendazole.

14

Which species of helminths are labeled as hookworms?

Ancylostoma and Necator.

15

What does one get infected with Hookworms?

Penetrate skin of feet. Do not walk barefoot.

16

What is the pathophysiology of Hookworms?

Same mechanism as strogyloides and ascariasis: they hatch on the intestines, travel through the bloodstream, lungs, penetrate alveoli, and then cough it up and swallow it. They then hook onto wall of small intestine and suck blood, leading to abdominal discomfort and anemia.

17

What is the treatment for hookworms?

Albendazole or mebendazole. Or pyrantel pamoate.

18

What are the three helminths that infect by burrowing into the skin?

[SAN].

Strongyloides.
Ancylostoma.
Necator.

19

What are cestodes?

Tapeworm.

20

What are the different routes of infection for Taenia solium and what does each produce?

1. Ingestion of the larvae in undercooked pork: adult tapeworm infects GI tract.
2. Ingestion of eggs in fecally contaminated food or water: Larval infection (cysticercosis).

21

What is the treatment for Taenia solium?

1. Praziquantel.
2. Albendazole + dexamethasone (the corticosterioid is added in cases for neurocysticercosis so that the symptoms do not get worse).

22

What is another name for Diphyllobothrium latum and what symptoms does it cause?

AKA Fish tapeworm, ingesting the larvae on raw fish. It can result in B12 deficiency that leads to megaloblastic anemia.

23

What is the treatment for Diphyllobothrium latum?

Praziquantel.

24

What is another name for the Dog tapeworm?

Echinococcus granulosus.

25

What is the pathophysiology of Echinococcus granulosus?

Ingested eggs, that hatch in the GI tract, enter the circulation, and form mature larval cysts in the host parenchyma: many end up in the liver or in the lungs. Sometimes the cysts leaks fluids that can lead to anaphylactic response.

26

What is the treatment for Echinococcus granulosus infection?

Surgical removal of cysts or aspiration followed by injection of scolicidal agent (ex: ethanol, hypertonic saline). Albendazole is usually given in conjunction in that procedure.

27

What are nematodes?

Roundworms.

28

What are trimatodes?

Flukes.

29

What are two high-yield blood flukes?

S. mansoni.
S. haematobium.

30

What is the pathophysiology of Schistosoma?

Eggs are released to the environment by and infected person. However, they need an intermediate host, which are snails. The larvae mature into cercaria inside snails. The cercaria penetrate the skin of humans, causing the "swimmer's itch." They immediately migrate to the lungs or the liver, in order to mature into their final form, to invade either the mesenteric vessels (S. mansoni) or lower urinary tract (S. haematobium). Embolized eggs can get stuck in portal system that can cause portal HTN and splenomegaly.