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Flashcards in Parasitology Deck (44)
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1
Q

Apicomplexia

A

Protozoa, include parasites that affect the GI tract and parasites that may affect blood and tissue

2
Q

Plasmodium

A

Include vivax, ovale/malariae, falciparum. Causes malaria

3
Q

Describe the life cycle of malaria

A
  1. anopheles mosquito bites human
  2. Sporozoite enters liver cell, matures into merozoite and enters blood
  3. Develop into trophozoite, RBC rupture releasing merozoite
  4. Some become gametocytes which are ingested by mosquito
  5. Gametocytes develop into sporozoite in mosquito, cycle begins
4
Q

Clinical presentation of malaria

A

Hx of recent travel to tropics and subtropics. Fever due to RBC rupture. Anemia due to RBC destruction

5
Q

Taenia saginata

A

cestode, beef tapeworm

6
Q

Taenia solium

A

cestode, pork tapeworm

7
Q

Cysticercus

A

larval of taenia solium which forms in human tissue. Most commonly in brain causing neurocysticercus

8
Q

Cysticercosis

A

cyst like lesions in the muscle, skin and brain caused by the ingestion of T. solium eggs. “measly” lesions look similar to infected pork

9
Q

How do we diagnosis intestinal taenia infections?

A

Finding characteristic eggs in the patient’s stool.

Cysticercosis is dx by specific EIA and confirmed by radiographic evidence of multiple tissue cysts

10
Q

Diphyllobothrium latum

A

fish tapeworm

Often seen in northern Europe and Japan. Megaloblastic anemia due to B12 deficiency

11
Q

schistosomiasis

A

trematodes- contact with freshwater contaminated with larval forms of schistosomes which penetrate skin.

Include: S. Mansoni, S. Japonicum (blood flukes) and S. Haematobium (bladder fluke)

12
Q

S. Mansoni and S. Japonicum

A

Acute infection: “katayama’s fever” including abdominal pain, diarrhea, fever and hepatosplenomegaly

Diagnosed by stoop O&P for recovery of ova

13
Q

S. Haematobium

A

causes bladder infection- hematuria and pyuria.

Diagnosed by urine for recovery of ova

14
Q

nematodes

A

multicellular metazoan

have a cylindrical body and complete digestive tract

Also called roundworms. Can infect the GI tract or the blood and tissues of humans

15
Q

Enterobius vermicularis

A

pin worm- most common helminthic infection in US

often in children, transmitted via fecal-oral

perianal itching

16
Q

Trematodes

A

flukes

Definitive host (humans) 
Intermediate host (fresh water snails) 

transmission: penetration of the skin or ingestion of cysts in undercooked fish or crab

17
Q

cestodes

A

tapeworms

Consists of Scolex (rounded head) and flat body

Transmission: ingestion of undercooked meat/fish containing larvae

infects GI or blood/tissue

18
Q

protozoa

A

single celled

reproduce sexually or by simple binary division

Trophozoite: mobile feeding and reproducing form

Cyst: non-mobile, dormant form

19
Q

Classes of protozoa

A

amoebas, flagellates, ciliates and apicomplexia

20
Q

How is Giardia acquired?

A

one of the most common parasitic infections in the US.

Acquired by drinking contaminated water. Trophozoite coats the small intestine, interfering with fat absorption.

greasy diarrhea

21
Q

How do we diagnosis Giardia

A

stool O&P
stool or serum for antigen testing
serology

22
Q

treatment for Giardia

A

Metronidazole (Flagyl)

23
Q

Trichomonas

A

Flagellate that causes STD

frothy, green, malodorous discharge.

24
Q

Amebiasis

A

caused by Entamoeba histolytica.

Causes dysentery so pts may present with blood diarrhea. Can also go to liver from colon and cause liver abscess.

Ingested RBCs can be seen in cytoplasm

25
Q

Name the 4 protozoa that cause malaria

A

Plasmodium falciparum-most common/deadly

Plasmodium vivax- chronic liver disease

Plasmodium ovale

Plasmodium malaria

26
Q

Clinical presentation of malaria

A

fever, chills, sweats. hx of recent travel

27
Q

life cycle of malaria

A
  1. Mosquito (vector) carries organisms within its salivary glands and injects them into humans while it feeds
  2. Sporozoites enter liver and sporozoites mature into merozoites
  3. organism grows in liver and spread RBCs which then burst
  4. Can lead to anemia and sticky RBCs that clot in organs
  5. Plasmodium vivax and plasmodium ovale create hypozoites in liver (latent form) which causes relapses.
28
Q

How do we diagnosis malaria?

A

exam blood under microscope (can see trophozoites in RBCs)

antigen detection tests

29
Q

how can we prevent malaria

A

long sleeved clothes/pants

insect repellant

prophylactic drugs prior to travel

30
Q

Trichuris trichiura

A

whipworm

usually seen in tropical climates

pts often asymptomatic but may have abdominal pain and diarrhea

31
Q

Ascaris lumbricoides

A

large intestinal worm

most common helminthic infection worldwide

may be asymptomatic

worms vomited up/removed from nares

32
Q

Necator americanus

A

hookworm

causes severe nutritional deficiency

seen in sub-saharan Africa, latin america and Caribbean

33
Q

Anclyostoma duodenale

A

hookworm

causes severe nutritional deficiency

34
Q

Strongyloides stercoralis

A

can result in life-threatening, disseminated hyper infections in immunosuppressed people

35
Q

Trichinella spiralis

A

usually acquired by eating undercooked pork

36
Q

Echinococcus granulosus

A

hydatid disease- pain as cyst containing the larva grow in the liver and lung.

Intermediate hosts: sheep, goat and pigs.

Definite host: dogs

37
Q

Echinococcus multilocularis

A

alveolar disease

38
Q

Acanthamoeba

A

CNS infection. Keratitis in people who wear contacts

free living in contaminated water and soil

39
Q

Naegleria fowleri

A

trophozoite enters nasal mucosa goes to CNS. Causes amebic meningoencephalitis (fatal)

contracted during recreational water activities in fresh and warm water

40
Q

Trypanosoma brucei rhodeisense

and

Trypanosoma brucei gambiense

A

African sleeping sickness by tsetse fly

causes changes in behavior,
confusion and changes in sleeping cycle

41
Q

Trpanosoma cruzi

A

Chagas disease by reduviid (kissing bug)

42
Q

Leishmania

A

sandfly bites human, transmitting promastigote, infecting macrophages

43
Q

Cryptosporidium parvum/hominis

A

severe chronic diarrhea in HIV patients

44
Q

Cyclospora cayetanensis

A

severe diarrhea in immunocompromised

acid-fast stain