Parasite infections of skin and soft tissue

Question 1

What organisms cause cutaneous leishmaniasis?

Answer 1

L. major, L. tropica, L. mexicana

Question 2

What form of leishmaniasis is found inside infected individuals?

Answer 2

Amastigote (intracellular)

Question 3

Are antibodies useful against leishmaniasis?

Answer 3

No (intracellular pathogens)

Question 4

What type of immunity is required to resolve leishmaniasis infection?

Answer 4

Cell mediated immunity - IFNy activation of macrophages

Question 5

What is the cause of river blindness?

Answer 5

Onchocerca volvulus

Question 6

In river blindness, which form of the nematode does the most damage?

Answer 6

Migrating and dying microfilariae

Question 7

How is mansonella transmitted?

Answer 7

Bite of infected midge

Question 8

How is dracunculosis transmitted?

Answer 8

Ingestion of infected copepods in water

Question 9

What is the pathogenesis of dracunculosis?

Answer 9

Larvae penetrate intestine and enter subcutaneous tissue - maturation takes about 1 year

Question 10

What is the cause of cutaneous larval migrans?

Answer 10

Ancylostoma (hookworms) that normally infect dogs or cats

Question 11

Patients with pertinent clinical symptoms and travel history to the Caribbean would indicate which potential infection?

Answer 11

Cutaneous larval migrans

Question 12

What is the appearance of scabies infection?

Answer 12

Short, serpentine, slightly raised, cutaneous tracts along which the mites have burrowed

Question 13

What causes Norwegian (crusted) scabies?

Answer 13

Hyperinfection of scabies mites

Question 14

What is the cause of Myiasis?

Answer 14

Dermatobia hominis - botfly

Question 15

How is Chaga’s disease transmitted?

Answer 15

Bite / defecation of reduviid bug

Question 16

What is the symptamology of Chaga’s disease?

Answer 16

1. Development of chagoma - Romana’s sign 2. Acute phase - fever, malaise, myalgia, hepatosplenomegaly

Question 17

Trichinosis is associated with what practice?

Answer 17

Eating undercooked meat (pork) containing encysted larvae

Question 18

Where do trichinella spiralis larvae encyst in the body?

Answer 18

WITHIN striated muscle cells

Question 19

What clinical symptoms aid in diagnosis of trichinosis?

Answer 19

Eosinophilia, elevated CPK, LDH, dietary history, periorbital edema

Question 20

How is loiasis transmitted?

Answer 20

Bite of mango fly

Question 21

How is loiasis diagnosed?

Answer 21

Observation of microfilariae in bloodstream, eosinophilia

Question 22

How are lung flukes transmitted?

Answer 22

Ingestion of fresh water crabs or crayfish

Question 23

Which parasitic infection is associated with “rusty sputum”?

Answer 23

Lung fluke