My instinct HAHAHAHAH

What is the etiologic agent of Chagas disease?**

   - a) Plasmodium falciparum

   - b) Leishmania donovani

   - c) Trypanosoma brucei

   - d) Trypanosoma cruzi

D

Which is the only trypanosome that has an intracellular amastigote stage?**

   - a) Trypanosoma brucei

   - b) Trypanosoma congolense

   - c) Trypanosoma vivax

   - d) Trypanosoma cruzi

D

What is the arthropod vector for Trypanosoma cruzi?**

   - a) Tsetse fly

   - b) Sand fly

   - c) Anopheles mosquito

   - d) Reduviid bug

D

8. Which of the following is a mode of transmission for Trypanosoma cruzi?

   - a) Inhalation of spores

   - b) Bite of an infected Anopheles mosquito

   - c) Blood transfusion

   - d) Contact with contaminated water

D

Which of the following hosts are considered zoonotic reservoirs for Trypanosoma cruzi?**

    - a) Fish and amphibians

    - b) Armadillos and raccoons

    - c) Birds and reptiles

    - d) Insects and spiders

B

What is the only stage of Trypanosoma cruzi found in the blood of an infected person?**

   - a) Epimastigotes

   - b) Promastigotes

   - c) Amastigotes

   - d) Trypomastigotes

D

Which of the following structures is (are) typical in trophozoites of E. histolytica? (Objective 3-9A) 

A. Single nucleus with a small karyosome

B. Unevenly distributed peripheral chromatin

C. Chromatoid bars 

D. Glycogen mass

a

E. histolytica infection is traditionally diagnosed by finding which of the following? (Objective 3-8) 

A. Adult and egg forms of the parasite in a suspected stool sample 

B. Trophozoites and/or cysts in a suspected stool sample 

C. Larvae in a suspected CSF sample 

D. Adult form of the parasite in suspected tissue samples

b

The infective stage of E. histolytica is which of the following? (Objective 3-5)

A. Trophozoite

B. Cyst

b

Which of the following factors is not responsible for the asymptomatic carrier state of a patient infected with E. histolytica? (Objective 3-7A)

A. Low virulence strain

B. Low inoculation into host

C. Intact patient’s immune system

D. Patient’s blood type

d

Which of the following prevention measures can control the spread of E. histolytica? (Objective 3-7C)

A. Drinking tap water

B. Using human feces as fertilizer

C. Boiling water or treat with iodine crystals

D. Practicing unsafe sex

c

A main difference between the trophozoites of E. hartmanni and E. histolytica is which of the follow ing? (Objective 3-11A)

A. Trophozoites of E. histolytica are smaller in size.

B. Presence of pseudopods

C. Trophozoites of E. hartmanni do not contain ingested red blood cells.

D. Nuclear structure and peripheral chromatin

c

The trophozoites of E. coli: (Objective 3-9A)

A. Have eight nuclei

B. Have a typical nucleus consists of a large, often irregularly shaped karyosome that is eccentrically located

C. Are characterized by a karyosome that is sur rounded by evenly distributed peripheral chromatin

D. Contain red blood cell inclusions

b

which of the following is not true about E. coli? (Objectives 3-2, 3-5, and 3-7C)

A. The parasite is found worldwide.

B. It is considered to be a pathogen.

C. The infection is transmitted through the ingestion of the infected cyst through contaminated food or drink.

D. The infection can be prevented by adequate dis posal of human feces and good personal hygiene practices.

b

Which of the following statements is not true about the cysts of E. polecki? (Objective 3-9A)

A. Cysts vary in shape from spherical to oval.

B. Cysts contain at least four nuclei.

C. The typical cyst nucleus resembles that of E. histolytica.

D. A diffuse glycogen mass may be present in the cytoplasm of cysts.

b

The appearance of an E. nana karyosome is usually which of the following? (Objective 3-9A)

A. Granular

B. Large and round

C. Small and round

D. Blotlike

d

Which of the following statements is true regarding E. nana? (Objectives 3-2 and 3-7)

A. E. nana is found primarily in cold regions of the world.

B. E. nana is prevalent in areas in which poor hygiene and substandard sanitary conditions exist.

C. E. nana is considered as a human pathogen, so treatment is mandatory.

D. Humans can obtain protection from E. nana via vaccination.

b

Iodamoeba bütschlii cysts typically

A. Contain four nuclei

B. Have a small karyosome in a central position

C. Lack chromatoid bars

D. Lack a glycogen mass

c

Transmission of I. bütschlii occurs when: (Objective 3-5A) A. The infective cysts are ingested in contaminated food or drink.

B. The infective trophozoites are ingested in con taminated food or drink.

C. Examining stool specimens from infected individuals D. An infected mosquito vector bites an unsuspect ing human.

a

Which of the following is a unique characteristic of E. gingivalis? (Objectives 3-5B, 3-9A, and 3-9C)

A. The trophozoites exhibit active motility via their pseudopods.

B. There is no known cyst form of this parasite.

C. The trophozoite has a single nucleus with charac teristics that resemble those of E. histolytica.

D. E. gingivalis is the only ameba that may ingest white blood cells.

d

E. gingivalis:

A. Is an intestinal ameba

B. Is a pathogen and must be treated with metronidazole C. Can be found in the mouth and in the genital tract

D. Has a typical amebic life cycle (i.e., trophozoites and cysts)

c

The known morphologic forms of Naegleria fowleri are: (Objective 3-5B)

A. Ameboid trophozoites, flagellate forms, and cysts

B. Ameboid trophozoites, immature cysts, and mature cysts

C. Eggs, larvae, and adults

D. Flagellate forms, cysts, and larvae

a

the specimen of choice for the recovery of N. fowleri is which of the following? (Objective 3-8)

A. Sputum

B. Stool

C. Cerebrospinal fluid

D. Urine

c

The ameboid trophozoites of N. fowleri enter the human body through all of the following routes except: (Objective 3-5B)

A. Entry through the nasal mucosa

B. Inhalation of contaminated dust

C. Sniffing contaminated water

D. Ingesting contaminated food and drink

d

The specimen of choice for diagnosing Acantham oeba species trophozoites and cysts is which of the following? (Objective 3-8)

A. Urine

B. Sputum

C. Cerebrospinal fluid

D. Stool

c

Humans may acquire Acanthamoeba species by which of the following? (Objective 3-5B)

A. Aspiration or nasal inhalation of the organisms

B. Direct invasion of the parasites in the eye

C. Swimming or bathing in contaminated water

D. A or B

d

Infections with Acanthamoeba species are encountered in which of the following anatomical parts?

A. Eye

B. Large intestines

C. Lungs

D. Liver

a

To prevent infection with Acanthamoeba species, contact lens wearers should avoid which of the fol lowing?

A. Strenuous exercise

B. Foods with high carbohydrate content

C. Wearing clothing made of cotton

D. Using homemade nonsterile saline solutions

d

Which of the following statements is not true about amebic trophozoites? (Objec tive 3-1)

A. Trophozoites are delicate and motile.

B. Trophozoites are easily destroyed by gastric juices.

C. Trophozoites are resistant to the envi ronment outside the host.

D. Replication occurs in the trophozoite stage.

c

3-7. Amebic dysentery is caused by: (Objec tive 3-6)

A. Entamoeba histolytica

B. Entamoeba coli

C. Entamoeba gingivalis

D. Endolimax nana

a

True/False. Treatment for patients with asymptomatic intestinal amebiasis is not recommended. (Objective 3-7)

A. True

B. False

a

Primary amebic meningoencephalitis is primarily caused by: (Objective 3-6)

A. Entamoeba histolytica

B. Naegleria fowleri

C. Entamoeba gingivalis

D. Acanthamoeba spp.

b

All flagellate life cycles possess trophozoite and cyst morphologic forms. (Objectives 4-5A and 4-5B)

A. True

B. False

b

The junvenile stage of developing nematode worms is referred to as: (Objective 8-1)

A. Eggs

B. Cysts

C. Larvae

D. Adults

c

Adult nematodes are never recovered in clinical samples. (Objective 8-6)

A. True B. False

b

hese individuals are prone to experiencing severe nematode infections: (Objective 8-7)

A. Completely healthy individuals with a heavy worm burden

B. Unhealthy individuals who are asymptomatic

C. Healthy individuals with a light worm burden

D. Unhealthy individuals with a heavy worm burden

d

The specimen of choice for the recovery of Enterobius vermicularis is: (Objective 8-9)

A. Stool

B. Urine

C. Cellophane tape prep

D. Tissue biopsy

c

The most likely individual to contract pinworm infec tion is(are) a(an): (Objective 8-7)

A. Older adult

B. Child

C. Adult prisoner

D. Military personnel

b

The morphologic forms recovered in cases of pinworm infection are which of the following? (Objective 8-6)

A. Eggs and adult females

B. Adult males and females

C. Eggs and larvae

D. Larvae and adult males

a

Trichuris trichiura eggs are characterized by the pres ence of which of the following? (Objective 8-10A)

A. Triple-layer cell wall

B. Flattened side

C. Hyaline polar plugs

D. Prominent cytostome

c

Of the following choices, the best laboratory diagno sis technique for the recovery of Trichuris trichiura eggs is which of the following? (Objective 8-9)

A. Zinc sulfate flotation

B. Modified acid-fast stain

C. Ethyl acetate concentration

D. Wright-Giemsa stain

a

Children infected with Trichuris trichiura commonly suffer from: (Objective 8-7)

A. Mental confusion

B. Hemoglobinuria

C. Severe anemia

D. Rectal prolapse

d

individuals contract Ascaris lumbricoides via which of the following? (Objective 8-6)

A. Inhalation

B. Insect bite

C. Ingestion

D. Inappropriate sexual practices

c

The term that describes the lack of an outer mammil lated albuminous coating is called which of the fol lowing? (Objective 8-1)

A. Unfertilized

B. Fertilzed

C. Corticated

D. Decorticated

d

The specimen of choice for the recovery of Ascaris lumbricoides eggs is which of the following? (Objec tive 8-9)

A. Stool

B. Gallbladder biopsy

C. Urine

D. Sputum

a

This adult hookworm is characterized by a buccal cavity that contains teeth. (Objective 8-10A)

A. Ancylostoma

B. Necator

C. Both Ancylostoma and Necator

D. Neither Ancylostoma nor Necator

a

Individuals contract hookworm via which of the fol lowing? (Objective 8-6)

A. Contaminated water

B. Skin penetration

C. Insect bite

D. Contaminated food

b

Which of the following are appropriate Ascaris lum bricoides prevention and control strategies?

A. Proper water treatment

B. Appropriate food handling

C. Use of insect repellent

D. Proper sanitation practices

d

This diagnostic stage of Strongyloides stercoralis is best seen in stool using fecal concentration tech niques: (Objective 8-9)

A. Eggs

B. Rhabditiform larvae

C. Filariform larvae

D. Adult worms

b

The life cycle of Stronglyoides most resembles that of which of the following? (Objective 8-12)

A. Pinworm

B. Whipworm

C. Hookworm

D. Threadworm

E. Human roundworm

c

The two clinical symptoms most commonly associated with Trichinella spiralis are which of the following? (Objective 8-7)

A. Constipation and abdominal pain

B. Vomiting urticaria

C. Diarrhea and vomiting

D. Abdominal pain and diarrhea

d

The specimen of choice for the identification of Trichi nella spiralis is which of the following? (Objective 8-9)

A. Cerebral spinal fluid

B. Stool

C. Skeletal muscle

D. Urine

c

The diagnostic stage of Trichinella spiralis is which of the following?

A. Encysted larvae

B. Cysts

C. Eggs

D. Adult worms

a

Trichinosis is acquired via which of the following?

A. Swimming in contaminated water '

B. Consuming contaminated water

C. Ingestion of contaminated food

D. Inhalation of contaminated air droplets

c

The two morphologic stages present in the Dracun culus medinensis are which of the following? (Objec tive 8-6) A. Eggs and larvae

B. Larvae and adults

C. Eggs and adults

D. None of the above

b

The specimen of choice for the recovery of Dracun culus medinensis is which of the following? (Objec tive 8-9)

A. Infected ulcer

B. Skeletal muscle

C. Stool

D. Blood

a

when humans contract Dracunculus medinensis, the parasite’s life cycle ceases to continue. (Objective 8-6)

A. True

B. False

C. Unable to determine

b

The eggs of which group of nematodes are indistinguishable? (Objective 8-12)

A. Whipworm and trichina worm

B. Hookworm and threadworm

C. Guinea worm and roundworm of man

D. Pinworm and whipworm

b

Once inside a human, these two nematodes take up residence outside the intestinal tract. (Objective 8-12)

A. Enterobius vermicularis and Strongy loides stercoralis B. Necator americanus and Ancylostoma duodenale

C. Dracunculus medinensis and Trichi nella spiralis

D. Trichuris trichiura lumbricoides

c

These two nematodes are similar in that they are both suspected of being transport hosts of Dientamoeba fragilis. (Objective 8-12)

A. Trichinella and Dracunculus

B. Necator and Trichuris

C. Strongyloides and Ancylostoma

D. Ascaris and Enterobius

d

he eggs of these two nematodes are never to rarely seen in stool samples. (Objective 8-12)

A. Trichina and threadworm

B. Whipworm and roundworm of man

C. Guinea worm and pinworm

D. Threadworm roundworm hookworm

a

1. Flattened on one side

2. Obvious albuminous coating

3. Surrounded by a nurse cell

4. Thin shell surrounding embryonic cleavage

5. Polar plug on each end

• A. Ascaris B. Anyclostoma C. Enterobius D. Trichuris

c, a, b, d

1. Hookworm

2. Guinea worm

3. Trichina worm

4. Pinworm

5. Roundworm of man

6. Whipworm

7. Threadworm

• A. Trichinella spiralis B. Trichuris trichiura C. Enterobius vermicularis D. Dracunculus medinensis E. Necator americanus

e. d. a. c. b

Differences in which of the following morphologic forms serve as criteria neces sary to speciate the hookworms? (Objec tive 8-12)

A. Eggs

B. Rhabditiform larvae

C. Encysted larvae

D. Adult worms

c

2. Surface covering

3. Fertilized

4. Absence of an outer albuminous coating

5. Pregnant

7. Formation without fertilization

• cuticle

• embryonated

• decorticated

• gravid

• parthenogenic

Speciation of the microfilariae can be done by recog nition of the distribution of nuclei in the tip of the tail and the presence or absence of a delicate transparent covering known as the: (Objective 9-1)

A. Flilariform

B. Cuticle

C. Sheath

D. Nucleus

c

What type of periodicity is exhibited if microfilariae appear in the blood of an individual at 2:00 p.m. each day? (Objective 9-1)

A. Nocturnal

B. Diurnal

C. Subperiodic

D. Biannual

b

Which of the following is similar for all microfilariae discussed?

A. Presence of a sheath

B. Ability to exhibit periodicity

C. Location of the adult worms

D. The basic life cycle

d

Diagnosis of infection with Wuchereria bancrofti is best accomplished by: (Objective 9-8)

A. Examination of stained peripheral blood taken during the night

B. Examination of stained tissue biopsy taken during the night

C. Use of serologic testing with blood taken during the day

D. Examination of stained lymph fluid taken during the day

a

Which of the following, in combination with alben dazole, has proven to be an important drug for the treatment of Bancroft’s filariasis? (Objective 9-9C)

A. Doxycycline

B. Ivermectin

C. Metronidazole

D. None of the above

b

Which of the following can be used in the differentia tion and identification of Brugia malayi? (Objective 9-13) A. Absence of a sheath

B. Absence of nuclei in the tail

C. Presence of a sheath that is very difficult to observe on Giemsa stain

D. Presence of two terminal nuclei in the tail

c

Select the ideal time period to collect blood samples for examination for the presence of the microfilariae of Brugia malayi. (Objective 9-8)

A. 10:00 p.m. to 4:00 a.m.

B. 10:00 a.m. to 4:00 p.m.

C. 4:00 p.m. to 8:00 p.m.

D. Any time of the day or night

a

A small threadlike worm is observed under the con junctiva of the eye. What organism and form is most likely? (Objective 9-8)

A. Wuchereria bancrofti adult

B. Brugia malayi microfilaria

C. Onchocera volvulus larva

D. Loa loa adult

d

What type of periodicity does Loa loa exhibit? (Objec tive 9-8)

A. Nocturnal

B. Subperiodic

C. Diurnal

D. None

c

how do the microfilariae of Onchocerca volvulus differ from those of other filarial? (Objective 9-13)

A. The presence of a sheath.

B. Nuclei are present continuous to the end of the tail

C. They exhibit diurnal periodicity

D. They are found in the skin rather than blood

d

Skin snips are the specimen of choice for diagnosis of infection with: (Objective 9-8)

A. Loa loa

B. Onchocerca volvulus

C. Brugia malayi

D. Wuchereria bancrofti

b

You live by a fast moving river in Eastern Africa. Which of the following filarial nematodes poses the greatest risk of infec tion for you? (Objective 9-5)

A. Brugia malayi

B. Onchocerca volvulus

C. Wuchereria bancrofti

D. Loa loa

b

Which of the following filarial nematodes is known as the blinding filaria? (Objective 9-3)

A. Brugia malayi

B. Onchocera volvulus

C. Loa loa

D. Mansonella ozzardi

b

The microfilariae of Brugia malayi are rec ognized by the: (Objective 9-11)

A. presence of a sheath and two distinct terminal nuclei in the tail

B. presence of a sheath and absence of nuclei in the tail C. absence of a sheath and nuclei continu ous to the tip of the tail

D. absence of a sheath and absence of nuclei in the tail

a

which of the filarial nematodes uses the mosquito as its vector?(Objective 9-5)

A. Loa loa

B. Onchocera volvulus

C. Wuchereria bancrofti

D. Mansonella ozzardi

c

Swelling of the lower extremities due to obstruction of the lymphatic system by adult filarial nematodes is known as: (Objective 9-1)

A. Periodicity

B. Lymphangitis

C. Eosinophilia

D. Elephantiasis

d

All of the following microfilariae lack a sheath except: (Objective 9-13)

A. Mansonella ozzardi

B. Mansonella perstans

C. Onchocera volvulus

D. Brugia malayi

d

Diagnosis of infection with Wuchereria bancrofti can be accomplished by all of the following methods except: (Objective 9-8)

A. Serologic testing

B. Tissue biopsies

C. Knott technique

D. Thick and thin peripheral blood smear

b

Which of the following filarial nema todes is transmitted by the Chrysops fly? (Objective 9-6)

A. Onchocerca volvulus

B. Mansonella ozzardi

C. Loa loa

D. Brugia malay

c

Which of the following filarial nematode infections is diagnosed by using skin snips rather than a peripheral blood smear? (Objective 9-8)

A. Onchocerca volvulus

B. Loa loa

C. Mansonella perstans

D. Wuchereria bancrofti

a

If an individual was planning to visit Africa, which of the following filarial nem atodes would not be a concern for poten tial infection? (Objective 9-2)

A. Loa loa

B. Wuchereria bancrofti

C. Brugia malayi

D. Mansonella ozzardi

c

The cestode morphologic form characterized by a segmented appearance that houses male and female reproductive structures is referred to as a(an): (Objec tive 10-1)

A. Scolex

B. Proglottid

C. Egg

D. Cyst

b

Characteristics of the cestodes include all the follow ing except: (Objective 10-9)

A. They are hermaphroditic.

B. They generally require intermediate host(s).

C. Their laboratory diagnosis consists of finding larvae in feces.

D. Their anatomic regions include the scolex, neck, and strobila.

c

A persistent cough, localized pain, and liver and lung involvement are associated with an infection with which of the following cestodes? (Objective 10-6)

A. Diphyllobothrium latum

B. Echinococcus granulosus

C. Both A and B

D. Neither A nor B

b

Which of the following are key distinguishing factors in differentiating an infection between T. saginata and T. solium? (Objective 10-9)

A. Egg morphology and number of uterine branches in proglottid

B. Presence of hooklets on scolex and egg morphology C. Presence of hooklets and number of uterine branches in proglottid

D. Egg morphology and presence of suckers on scolex

c

The primary means of developing an intestinal infec tion with Taenia spp. is via which of the following? (Objective 10-5)

A. Skin penetration of larvae

B. Ingestion of raw or poorly cooked meat

C. Egg consumption

D. Drinking contaminated water

b

Which is the preferred drug for treating intestinal infection by Taenia spp.? (Objective 10-7)

A. Praziquantel

B. Penicillin

C. Nicolasamide

D. Pentamidine

a

Which of the following is characteristic of an H. diminuta egg? (Objective 10-10A)

A. Spherical, with radial striations

B. Ellipsoid, with terminal polar plugs

C. Oval, with thin shell and polar filaments

D. Oval, with polar thickenings and no filaments

d

The infective stage of H. diminuta for humans is which of the following? (Objective 10-5)

A. Rhabditiform larva

B. Cysticeroid larva

C. Embryonated egg

D. Encysted form

b

Prevention and control measures against H. diminuta include all except which of the following? (Objec tive 10-7B)

A. Vaccination program

B. Effective rodent control

C. Inspection of food prior to consumption

D. Protection of food from rodent

a

A primary differential feature between an H. nana egg and H. diminuta egg is which of the following?

A. A flattened side for H. diminuta egg

B. A thick shell for H. nana egg

C. Polar filaments in H. nana egg

D. Radial striations in H. diminuta egg

c

The characteristic of the life cycle of H. nana that differentiates it from the other cestodes is which of the following? (Objective 10-9)

A. Lack of an intermediate host.

B. Infective larval stage.

C. Need for external environment

D. Larval passage through the lungs

a

Which of the following does not apply to H. nana?

A. Dwarf tapeworm

B. Steatorrhea

C. Proper hygiene and sanitation procedures

D. Praziquantel therapy

b

A unique characteristic of Dipylidium caninum is which of the following? (Objective 10-10A)

A. Lack of suckers on the scolex

B. Formation of egg packets

C. Proglottid resemblance to Taenia solium

D. Alternation of female and male proglottids

b

A 2-year-old girl and her pet dog were diagnosed with D. caninum infection. This infection was acquired by which of the following? (Objective 10-5)

A. Ingestion of the parasite’s egg

B. Penetration of soil larva

C. Ingestion of a flea

D. Consumption of poorly cooked beef

c