Parasitology I-II

Question 1

What are the protozoa that are spread human to human?

Answer 1

• Cryptosporidiosis
• Amebiasis
• Giardiasis

Question 2

What are the protozoa that are spread animal to human?

Answer 2

• Cryptosporidiosis
• Toxoplasmosis
• Giardiasis

Question 3

What are the vector borne protozoal diseases?

Answer 3

Malaria
Leishmanias
American Trypanosomiasis
African Trypanosomiasis

Question 4

Malaria Vector

Answer 4

Anopheles Mosquito

Question 5

Leishmanias Vector

Answer 5

Sand Fly

Question 6

American Trypanosomiasis (Chagas Disease) Vector

Answer 6

Reduviid Bug

Question 7

African Trypanosomiasis (Sleeping Sickness) Vector

Answer 7

Tsetse Fly

Question 8

Plasmodium falciparum Dx

Answer 8

Blood smear

Question 9

Leishmania tropica Dx

Answer 9

Skin scraping and biopsy

Question 10

Trypanosoma cruzii Dx

Answer 10

Tissue biopsy or blood smear

Question 11

Giardia lamblia Dx

Answer 11

Stool ova & parasite exam, immunofluorescence

Question 12

Cryptosporidium Dx

Answer 12

Stool ova & parasite exam, immunofluorescence

Question 13

Entamoeba histolytica Dx

Answer 13

Stool ova & parasite screen

Question 14

Toxoplasmosis Dx

Answer 14

Tissue biopsy (brain, lymphnode, other) or serology

Question 15

What are the protozoa indigenous to the US mainland?

Answer 15

• amebiasis
• giardiasis
• toxoplasmosis
• babesiosis pneumoocystis
• cryptosporidiosis

Question 16

What is the prophylactic treatment for Plasmodium species?

Answer 16

Mefloquine or chloroquine

Question 17

What is the prophylactic treatment for Pneumocystis jiroveci?

Answer 17

TMP/SMX in AIDS patients only

Question 18

What is the prophylactic treatment for Toxoplasmosis gondii?

Answer 18

TMP/SMX in AIDS patients only

Question 19

What is the life cycle of malaria in the mosquito?

Answer 19

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

Question 20

What is the life cycle of malaria in the human?

Answer 20

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

Question 21

Sporozoite

Answer 21

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.

Question 22

Schizont

Answer 22

A mature sporozoite form that multiplies into thousands of merozoites

Question 23

Merozoite

Answer 23

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.

Question 24

Trophozoite

Answer 24

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.

Question 25

What is the RBC | Ag for P. vivax?

Answer 25

Duffy Ag

Question 26

Which of the Plasmodium has widespread resistance to chloroquine?

Answer 26

P. falciparum

Question 27

What Plasmodium are Schuffner’s dots indicative of?

Answer 27

P. vivax and P. ovale

Question 28

What Plasmodium are electron dense knobs indicative of?

Answer 28

P. falciparum

Question 29

What are some of the clinical manifestations of malaria?

Answer 29

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

Question 30

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

Answer 30

P. vivax and P. ovale

Question 31

Name the organs most severely affected in fulminant falciparum malaria.

Answer 31

– Cerebral malaria – Renal failure – Pulmonary edema

Question 32

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

Answer 32

Sporogony

Question 33

What is the treatment for P. vivax/ovale?

Answer 33

Chloroquine + primaquine

Question 34

What is the origin of Plasmodium knowlesi?

Answer 34

Monkeys

Question 35

What is the vector for Babesiosis?

Answer 35

Ixodes scapularis – Tick

Question 36

What are the clinical manifestations of babesiosis?

Answer 36

Majority have NO symptoms – Fever – Headache – Fatigue – Hemolytic anemia

Question 37

What is characteristic on the blood smear of babesiosis?

Answer 37

Tetrads

Question 38

What is the reservoir for Toxoplasma gondii?

Answer 38

Cats mainly. Also sheep, cattle and pigs.

Question 39

What is the the greatest risk for passing Toxoplasma intrauterinely?

Answer 39

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

Question 40

Name the human cell in which babesia species are found.

Answer 40

RBCs

Question 41

What is the treatment for babesiosis?

Answer 41

Atovaquone plus azithromycin

Question 42

What can T. gondii cause in immunocompromised patients?

Answer 42

- encephalitis | - myocarditis

Question 43

Where is Cryptosporidium found in a human host?

Answer 43

It carries out its life cycle in the intestinal villi

Question 44

What are the clinical manifestation of Cryptosporidium?

Answer 44

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

Question 45

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

Answer 45

The diarrhea will continue relentlessly until immunity is restored

Question 46

What is the reservoir for amebiasis?

Answer 46

Humans

Question 47

What is characteristic of E. histolytica infection?

Answer 47

“Flask” ulcers

Question 48

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

Answer 48

- cysts ingested (fecal oral) | - sex

Question 49

What are the clinical findings in amebiasis?

Answer 49

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

Question 50

What are the symptoms of Giardia infection?

Answer 50

Malabsorption type of diarrhea – Fat – Carbohydrate

Question 51

What are the transmission mechanisms of Giardia?

Answer 51

Water, food, person-person, sex

Question 52

What is a key feature of Trichomonas vaginalis on microscopy?

Answer 52

HIGHLY motile organism

Question 53

What is the transmission mechanism of Trichomonas vaginalis?

Answer 53

Sex

Question 54

What are the signs of T. vaginalis infection?

Answer 54

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

Question 55

What is the treatment for T. vaginalis infection?

Answer 55

– Metronidazole – Tinidazole ALSO TREAT MALE PARTNER

Question 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?

Answer 56

Amastigote

Question 57

What is the pathogenesis of leishmaniasis?

Answer 57

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

Question 58

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

Answer 58

Trypomastigote

Question 59

What are some of the symptoms of African trypanosomiasis?

Answer 59

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

Question 60

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

Answer 60

Trypanosoma cruzi. American Trypanosomiasis

Question 61

Which protozoan causes megaesophagus or megacolon?

Answer 61

Trypanosoma cruzi

Question 62

The insect vector of Trypanosoma cruzi is the ___________

Answer 62

Reduviid Bug

Question 63

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

Answer 63

Intestine of the cat

Question 64

What are the clinical features of Chagas' Disease?

Answer 64

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

Question 65

What are the symptoms of Pneumocystis jiroveci infection?

Answer 65

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

Question 66

Is Pneumocystis jiroveci a protozoan?

Answer 66

No it is a fungus

Question 67

How do humans acquire infection with Toxoplasma gondii?

Answer 67

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

Question 68

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

Answer 68

Encephalitis

Question 69

How is the specific diagnosis of Pneumocystis jiroveci pneumonia established?

Answer 69

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

Question 70

Name the infective form of Entamoeba histolytica.

Answer 70

Trophoziote

Question 71

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

Answer 71

Liver

Question 72

The major site of infection with Giardia lamblia is ___________________________.

Answer 72

Intestines

Question 73

Giardia lamblia causes diarrhea by | _____________

Answer 73

Fat/Carbohydrate Malabsorption

Question 74

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

Answer 74

Explosive watery diarrhea