Parasitology

Question 1

This is the only ciliated protozoan to cause human disease (dysentery)

Answer 1

Balantidium coli (Protozoa); Balantidial dysentery causes round-based, wide-necked intestinal ulcers

Question 2

This protozoan is transmitted by the bite of an Ixodes tick; diagnosed via the presence of intraerythrocytic ring-shaped trophozoites in tetrads (Maltese cross)

Answer 2

Babesia microti

Question 3

Diagnostic stage/Infective stage: Taenia solium

Answer 3

Gravid proglottids/Cysticerci and eggs; Cysticerci only for T. saginata

Question 4

Among the Taenia species, which contains more primary uterine branches in its gravid proglottids?

Answer 4

Taenia saginata (Cestode)

Question 5

Diagnostic stage/Infective stage: Diphyllobothrium latum

Answer 5

Unembryonated egg/Pterocercoid larvae

Question 6

In Dog tapeworm infection, man is a/an __________ host.

Answer 6

Accidental

Question 7

This type of parasite is described as a free living organism that passes through the digestive tract without infecting the host.

Answer 7

Spurious parasite

Question 8

Man is a _______ host to Trichinella spiralis; the parasite does not develop further to its later stages.

Answer 8

Paratenic host

Question 9

Describe the motility of the causative organism implicated as the most common cause of backpacker’s diarrhea (in ecological/natural sources of water)

Answer 9

Falling leaf motility (Giardia lamblia)

Question 10

Malaria is transmitted via the bite of what kind of mosquito?

Answer 10

Anopheles flavirostris minimus

Question 11

Diagnostic stage/Infective stage: Plasmodium spp.

Answer 11

Immature Trophozoites (ring form)/Sporozoites

Question 12

Malaria manifesting as malignant tertian fever, highest level of parasitemia, banana-shaped gametocytes, multiple drug resistance, with cerebral affectation, is due to what species?

Answer 12

P. falciparum

Question 13

Fever manifesting every 3 days (eg. Mon (+), Tue, Wed (-), Thu (+)), associated with the lowest parasitemia, recrudescence and prefers old RBCs is characteristic of Malaria secondary to what species?

Answer 13

P. malariae

Question 14

Malarial dot: punctate granulations present in RBCs invaded by P. ovale/vivax

Answer 14

Schuffner dots

Question 15

Malarial dot: coarse granulations present in RBCs invaded by P. falciparum, comma-shaped

Answer 15

Maurer dots

Question 16

Malarial dot: fine dots present in RBCs invaded by P. malariae

Answer 16

Ziemann dots

Question 17

This is a severe complication of P. falciparum malaria characterized by intravascular hemolysis, massive hemoglobinuria and acute renal failure

Answer 17

Blackwater fever

Question 18

Septic shock in P. falciparum malaria is also known as?

Answer 18

Algid malaria

Question 19

This antimalarial drug is both a tissue schizontizide and gametocide, used in the eradication if hypnozoites and is contraindicated in pregnant women.

Answer 19

Primaquine

Question 20

Vector: American trypanosomiasis

Answer 20

Reduviid bug/Triatomine bug (Trypanosoma cruzi)

Question 21

Diagnosis: Fever, lymphadenopathy, hepatosplenomegaly, (+) Romana’s sign with a characteristic nodule seen at bite site

Answer 21

Acute Chagas’ disease; characteristic nodule - Chagoma

Question 22

Vector: Trypanosoma brucei

Answer 22

Tsetse fly/Glossina fly

Question 23

What is the most common tapeworm in developed countries?

Answer 23

Hymenolepis nana/Dwarf tapeworm (Cestode)

Question 24

Differentiate egg morphology among Schistosoma species (mansoni, japonicum, haematobium)

Answer 24

S. mansoni = oval shaped with sharp lateral knob
S. japonicum = rounded with rudimentary, small lateral knob
S. haematobium = oval shaped with sharp terminal knob

Question 25

Infective stage/Diagnostic stage: Endemic Hemoptysis

Answer 25

Metacercariae/Unembryonated egg (Paragonimus westermanii)

Question 26

Diagnosis: Chronic cough with hemoptysis, weight loss, body malaise, CXR: ring shadow opacity

Answer 26

Paragonimus westermanii (Trematode)

Question 27

Parasites with lung migration phase include:

Answer 27

``` Strongyloides stercoralis Ancylostoma duodenale Necator americanus Ascaris lumbricoides (Nematodes) ```

Question 28

Diagnosis: Allergic, painful pharyngitis secondary to intake of infected, raw sheep liver. May manifest with obstructive jaundice due to preponderance of parasite to reside in bile ducts.

Answer 28

Fasciola hepatica (Trematode)

Question 29

What parasite causes Primary Amebic Meningoencephalitis, commonly acquired while swimming in contaminated water?

Answer 29

Naegleria fowleri (Protozoa)

Question 30

Malignancy associated with Clonorchis sinensis, Opisthorchis viverrini?

Answer 30

Cholangiocarcinoma (Liver flukes)