Parasitology I-II Flashcards Preview

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Flashcards in Parasitology I-II Deck (74):
1

What are the protozoa that are spread human to human?

- Cryptosporidiosis
- Amebiasis
- Giardiasis

2

What are the protozoa that are spread animal to human?

- Cryptosporidiosis
- Toxoplasmosis
- Giardiasis

3

What are the vector borne protozoal diseases?

Malaria
Leishmanias
American Trypanosomiasis
African Trypanosomiasis

4

Malaria Vector

Anopheles Mosquito

5

Leishmanias Vector

Sand Fly

6

American Trypanosomiasis (Chagas Disease) Vector

Reduviid Bug

7

African Trypanosomiasis (Sleeping Sickness) Vector

Tsetse Fly

8

Plasmodium falciparum Dx

Blood smear

9

Leishmania tropica Dx

Skin scraping and biopsy

10

Trypanosoma cruzii Dx

Tissue biopsy or blood smear

11

Giardia lamblia Dx

Stool ova & parasite exam, immunofluorescence

12

Cryptosporidium Dx

Stool ova & parasite exam, immunofluorescence

13

Entamoeba histolytica Dx

Stool ova & parasite screen

14

Toxoplasmosis Dx

Tissue biopsy (brain, lymphnode, other) or serology

15

What are the protozoa indigenous to the US mainland?

- amebiasis
- giardiasis
- toxoplasmosis
- babesiosis pneumoocystis
- cryptosporidiosis

16

What is the prophylactic treatment for Plasmodium species?

Mefloquine or chloroquine

17

What is the prophylactic treatment for Pneumocystis jiroveci?

TMP/SMX in AIDS patients only

18

What is the prophylactic treatment for Toxoplasmosis gondii?

TMP/SMX in AIDS patients only

19

What is the life cycle of malaria in the mosquito?

Sporogony - gametocytes are formed which lead to a zygote then and oocyst and a sporozoite.

20

What is the life cycle of malaria in the human?

Schizogony - sporozoites are injected which can enter into one of two cycles:

- Exoerythrocytic - Liver -> the sporozoite will become a hepatic schizont which is then converted to a merozoite.

- Erythrocytic -> the sporozoite become a trophozoite then a RBC schizont before it is converted to a merozoite or a gametocyte before it is taken up by a mosquito again in a blood meal

21

Sporozoite

A motile sporelike stage in the life cycle of some parasitic sporozoans (e.g., the malaria organism) that is typically the infective agent introduced into a host.

22

Schizont

A mature sporozoite form that multiplies into thousands of merozoites

23

Merozoite

Merozoites infect red blood cells and then rapidly reproduce asexually. The red blood cell host is destroyed by this process, which releases many new merozoites that go on to find new blood-borne hosts. Merozoites are non-motile.

24

Trophozoite

It is the activated, intracellular feeding stage in the apicomplexan life cycle. After gorging itself on its host, the trophozoite undergoes schizogony and develops into a schizont, later releasing merozoites.

25

What is the RBC
Ag for P. vivax?

Duffy Ag

26

Which of the Plasmodium has widespread resistance to chloroquine?

P. falciparum

27

What Plasmodium are Schuffner’s dots indicative of?

P. vivax and P. ovale

28

What Plasmodium are electron dense knobs indicative of?

P. falciparum

29

What are some of the clinical manifestations of malaria?

• Chills, fever, headache, myalgias, nausea, splenomegaly
- cycles of fever with hemolytic anemia
• Anemia, thrombocytopenia

30

Which malaria species can persist in the liver and relapse in the blood after treatment?

P. vivax and P. ovale

31

Name the organs most severely affected in fulminant falciparum malaria.

– Cerebral malaria
– Renal failure
– Pulmonary edema

32

The sexual phase of the malaria life cycle in which gametocytes mature to the sporozoite is known as ________

Sporogony

33

What is the treatment for P. vivax/ovale?

Chloroquine + primaquine

34

What is the origin of Plasmodium knowlesi?

Monkeys

35

What is the vector for Babesiosis?

Ixodes scapularis – Tick

36

What are the clinical manifestations of babesiosis?

Majority have NO symptoms

– Fever
– Headache
– Fatigue
– Hemolytic anemia

37

What is characteristic on the blood smear of babesiosis?

Tetrads

38

What is the reservoir for Toxoplasma gondii?

Cats mainly. Also sheep, cattle and pigs.

39

What is the the greatest risk for passing Toxoplasma intrauterinely?

The greatest risk is when it is acquired by mother in 3rd trimester

40

Name the human cell in which babesia species are found.

RBCs

41

What is the treatment for babesiosis?

Atovaquone plus azithromycin

42

What can T. gondii cause in immunocompromised patients?

- encephalitis
- myocarditis

43

Where is Cryptosporidium found in a human host?

It carries out its life cycle in the intestinal villi

44

What are the clinical manifestation of Cryptosporidium?

– Explosive, watery diarrhea
– Abdominal pain
– Lasts one to two weeks

45

What is the difference in the infection of the immunocompromised with Cryptosporidium?

The diarrhea will continue relentlessly until immunity is restored

46

What is the reservoir for amebiasis?

Humans

47

What is characteristic of E. histolytica infection?

“Flask” ulcers

48

What is the transmission of amebiasis (E. histolytica)?

- cysts ingested (fecal oral)
- sex

49

What are the clinical findings in amebiasis?

– Asymptomatic
– Nonspecific diarrhea
– Dysentery (pain, fever, blood, pus)
– Spread – liver, pleural (lung), pericardium

50

What are the symptoms of Giardia infection?

Malabsorption type of diarrhea – Fat – Carbohydrate

51

What are the transmission mechanisms of Giardia?

Water, food, person-person, sex

52

What is a key feature of Trichomonas vaginalis on microscopy?

HIGHLY motile organism

53

What is the transmission mechanism of Trichomonas vaginalis?

Sex

54

What are the signs of T. vaginalis infection?

• Damages squamous mucosa of female genital tract
– Neutrophilic inflammatory reaction
– Petechial hemorrhages

55

What is the treatment for T. vaginalis infection?

– Metronidazole
– Tinidazole

ALSO TREAT MALE PARTNER

56

Which morphologic stage of leishmania is seen within macrophages in skin biopsy in the cutaneous form or in the liver or spleen in the visceral form?

Amastigote

57

What is the pathogenesis of leishmaniasis?

• Injected promastigotes opsonized with complement
• Taken up by macrophages; amastigotes multiply intracellularly
• Released to another cell or fly

58

Which morphologic stage of trypanosome circulates in the blood of people infected with Trypanosoma cruzi or Trypanosoma brucei gambiense?

Trypomastigote

59

What are some of the symptoms of African trypanosomiasis?

– Local lesion (chancre)
– Acute illness with fever
– Encephalopathy

60

What is Chagas’ Disease caused by? What is it AKA?

Trypanosoma cruzi.

American Trypanosomiasis

61

Which protozoan causes megaesophagus or megacolon?

Trypanosoma cruzi

62

The insect vector of Trypanosoma cruzi is the ___________

Reduviid Bug

63

The sexual phase of the life cycle of Toxoplasma gondii takes place in the _________________

Intestine of the cat

64

What are the clinical features of Chagas' Disease?

– Acutefebirle
– Chronic heart failure, arrhythmia
– Megaesophagus and megacolon

65

What are the symptoms of Pneumocystis jiroveci infection?

– Fever
– Dry cough
– Severe dyspnea
• CXR Diffuse interstitial infiltrates

66

Is Pneumocystis jiroveci a protozoan?

No it is a fungus

67

How do humans acquire infection with Toxoplasma gondii?

Transmission by ingestion of oocysts (cat feces) or undercooked meat

68

What is the most common manifestation of toxoplasmosis in persons with AIDS?

Encephalitis

69

How is the specific diagnosis of Pneumocystis jiroveci pneumonia established?

See cysts in lung tissue and secretions with silver stain or DFA

70

Name the infective form of Entamoeba histolytica.

Trophoziote

71

The organ most commonly involved in extra-intestinal amebiasis is the ______________

Liver

72

The major site of infection with Giardia lamblia is ___________________________.

Intestines

73

Giardia lamblia causes diarrhea by
_____________

Fat/Carbohydrate Malabsorption

74

The clinical manifestation caused by cryptosporidium if it is acquired by healthy people is _________________

Explosive watery diarrhea

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