Parasitic and fungal lung infections

Question 1

Benzimidazole

Answer 1

• Bind microtubules and prevent movement and associated cell processes

i.e. albendazole

Question 2

Avermectin

Answer 2

• Acts on worm GABA complex
• Inhibits GABA synapses in peripheral NS leading to paralysis

i.e. ivermectin

Question 3

Pyrazino isoquilnoline

Answer 3

• Broad spectrum calcium agonist (against trematodes and cestodes)
• Results in increased intracellular Ca release that leads to muscular contraction

i.e. praziquantel

Question 4

Asacaris lumbricoides infection sxs and pathology

Answer 4

Question 5

Tx. of Ascaris lumbricoides infection

Answer 5

Albendazole

Question 6

Tx. for Strongyloides stercocalis infection (threadworm)

Answer 6

Ivermectin

Repeat Tx common (ivermectin only effective against adult form)

Question 7

Hookworm infection

Answer 7

Necator americanus

Ancylostoma duodenale

Question 8

Dx of hookworm infection

Answer 8

Eggs in stool

Question 9

Tx of hookworm infection

Answer 9

Tx anemia

Albendazole or mebendazole

Question 10

Answer 10

Hookworm egg

Question 11

Mnemonic for intestinal roundworms

Answer 11

Question 12

Only intestinal roundworms that shows larval form in stool

Answer 12

Strongyloides stercoralis

Question 13

Paragonimus westermani

Answer 13

Tx: praziquantel

Dx: ID eggs in sputum or feces

Question 14

Most common pulmonary and systemic mycosis of humans

Answer 14

Histoplasma capsulatum

The spores (microcondidia – not the larger macrocondidia, chlamydospores) are inhaled from disturbed
airborne soil.

Question 15

Histoplasma capsulatum syndrome in immune-competent hosts

Answer 15

• severe acute pulmonary syndrome (caseating lesions that can calcify - “birdshot” CXR)
• Histoplasmoma - single pulmonary parenchymal nodule - “coin lesion on CXR)
• Mediastinal obstructuve syndrome

Question 16

Histoplasma capsulatum syndrome in immunocompromised hosts

Answer 16

• Chronic pulmonary histoplasmosis (COPD - presentation similar to TB)

Question 17

What is the most common and likely clinical manifestation of cyptoccocal disease?

Answer 17

CNS disorder

Question 18

A man presents with high eosinophilia and pneumonia like symptoms. A sputum sample is obtained and an unusual yeast form is found. It is round with multiple buddings. This morphology is associated with what fungal infection?

Answer 18

Paracoccidioides

Question 19

In whi US state is one most likely to contract Blastomyces infection?

Answer 19

TN

Endemic to TN

Question 20

In Cryptococcal infections, which diagnostic test is often used for identification?

Answer 20

Latex agglutination of CSF antigens

Question 21

The parasite Necator americanus is acquired by humans how?

Answer 21

Skin penetration

Question 22

Loeffler’s Syndrome is best characterized as which of the following?

A. Eosinophilic myocarditis
B. Elevated eosinophils in blood
C. Pulmonary eosinophilia
D. PNA due to a respiratory pathogen

Answer 22

C. Pulmonary eosinophilia

Question 23

MOA of amphotericin B

Answer 23

It binds to ergosterol directly to cause oxidation and disruption of the cellular membrane

Amphotericin B binds to ergosterol in the fungal cell membrane, which leads to the formation of pores, ion leakage and ultimately fungal cell death

Question 24

First-line Tx for Pneumoncystis pneumonia

Answer 24

TMP-SMX

Question 25

Which of the following parasites is associated with fecal/oral transmission?

Answer 25

A. *Ascaris lumbricoides*

Question 26

What drug inhibits cytochrome P-450 dependent 14-alpha-demethylase?

Answer 26

-Azole drugs (prevents fromation of lanosterol - precursor to ergosterol)

Question 27

Which parasitic pathogen undergoes its complete life-cycle in a single human host?

Answer 27

*Strogyloides stercoralis* ## Footnote Acquired through skin penetration

Question 28

What is the MOA for the drug that Tx's *Strogyloides stercoralis*

Answer 28

Inhibit GABA synapses in peripheral nervous system leading to paralysis ## Footnote Ivermectin

Question 29

Answer 29

A. Septation D. Hyphal branching

Question 30

Answer 30

A. Galactomannan | Galactomannan test

Question 31

Answer 31

Voriconazole

Question 32

Answer 32

B. Other people

Question 33

Answer 33

Dx: Lung fluke (*Paragonimus*) | Trematode ## Footnote Secondary host - snail/crustacean

Question 34

Answer 34

D. Binds to calcium receptor leading to release of intracellular calcium and muscular contraction (Praziquantel)

Question 35

Answer 35

*Blastomyces dermatitidis*

Question 36

Geographic distribution of *Coccidiodes* in US

Answer 36

US SW (desert)

Question 37

Answer 37

A. Spherule w/ endospores ## Footnote B = Blastomyces

Question 38

ID

Answer 38

Histoplasma

Question 39

From which ecological niche can one most likely acquire histoplasmosis?

Answer 39

Bat and bird droppings | High nitrogen content faciliates histo growth ## Footnote Cryptococcus is also associated w/ birds (pigeon roosts)

Question 40

What Rx is used in Tx in mild cases of histoplasmosis?

Answer 40

Itraconazole

Question 41

DOC to Tx mild cases of systemic, dimorphic fungal infections

Answer 41

Intraconazole