HARR EE1 Flashcards
1
Q
The incorrect match between organism and the
appropriate diagnostic procedure is:
A. Onchocerca volvulus—examination of skin snips
B. Cryptosporidium—modified acid-fast stain
C. Echinococcus granulosus—routine ova and parasite
examination
D. Schistosoma haematobium—examination of urine
sediment
A
C. Echinococcus granulosus—routine ova and parasite
examination
2
Q
In a patient with diarrhea, occasionally Entamoeba
histolytica/E. dispar (four nucleated cysts, no
chromatoidal bars) are identified as being present;
however, these cells, which are misdiagnosed as
protozoa, are really:
A. Macrophages
B. Polymorphonuclear leukocytes
C. Epithelial cells
D. Eosinophils
A
B. Polymorphonuclear leukocytes
3
Q
Charcot–Leyden crystals in stool may be associated
with an immune response and are thought to be
formed from the breakdown products of:
A. Neutrophils
B. Eosinophils
C. Monocytes
D. Lymphocytes
A
B. Eosinophils
4
Q
Parasitic organisms that are most often transmitted sexually include: A. Entamoeba gingivalis B. Dientamoeba fragilis C. Trichomonas vaginalis D. Diphyllobothrium latum
A
C. Trichomonas vaginalis
5
Q
The incorrect match between the organism and
one method of acquiring the infection is:
A. Trypanosoma brucei rhodesiense—bite of sand
fleas
B. Giardia lamblia—ingestion of water
contaminated with cysts
C. Hookworm—skin penetration of larvae from soil
D. Toxoplasma gondii—ingestion of raw or rare
meats
A
A. Trypanosoma brucei rhodesiense—bite of sand
fleas
6
Q
Upon examination of stool material for
Cystoisospora belli, one would expect to see:
A. Cysts containing sporozoites
B. Precysts containing chromatoidal bars
C. Oocysts that are modified acid-fast variable
D. Sporozoites that are hematoxylin positive
A
C. Oocysts that are modified acid-fast variable
7
Q
Which specimen is the least likely to provide recovery of Trichomonas vaginalis? A. Urine B. Urethral discharge C. Vaginal discharge D. Feces
A
D. Feces
8
Q
Which of the following is the best technique to identify Dientamoeba fragilis in stool? A. Formalin concentrate B. Trichrome-stained smear C. Modified acid-fast–stained smear D. Giemsa’s stain
A
B. Trichrome-stained smear
9
Q
One of the following protozoan organisms has
been implicated in waterborne and foodborne
outbreaks within the United States. The suspect
organism is:
A. Pentatrichomonas hominis
B. Dientamoeba fragilis
C. Giardia lamblia
D. Balantidium coli
A
C. Giardia lamblia
10
Q
A Gram stain from a gum lesion showed what appeared to be amoebae. A trichrome smear showed amoebae with a single nucleus and partially digested PMNs. The correct identification is: A. Trichomonas tenax B. Entamoeba histolytica/E. dispar C. Entamoeba gingivalis D. Entamoeba polecki
A
C. Entamoeba gingivalis
11
Q
An Entamoeba histolytica trophozoite has the
following characteristics:
A. Central karyosome in the nucleus, ingested
RBCs, and clear pseudopodia
B. Ingested RBCs, clear pseudopodia, and uneven
chromatin on the nuclear membrane
C. Ingested RBCs, clear pseudopodia, and large
glycogen vacuoles in cytoplasm
D. Large, blotlike karyosome, ingested white blood
cells (WBCs), and granular pseudopods
A
A. Central karyosome in the nucleus, ingested
RBCs, and clear pseudopodia
12
Q
A 12-year-old girl is brought to the emergency
department with meningitis and a history of
swimming in a warm-water spring. Motile
amoebae that measure 10 μ in size are seen in
the CSF and are most likely:
A. Iodamoeba bütschlii trophozoites
B. Endolimax nana trophozoites
C. Dientamoeba fragilis trophozoites
D. Naegleria fowleri trophozoites
A
D. Naegleria fowleri trophozoites
13
Q
Characteristics of the rhabditiform (noninfective)
larvae of Strongyloides stercoralis include a:
A. Short buccal capsule and large genital
primordium
B. Long buccal capsule and pointed tail
C. Short buccal capsule and small genital
primordium
D. Small genital primordium and notch in tail
A
A. Short buccal capsule and large genital
14
Q
Visceral larva migrans is associated with which of the following organisms? A. Toxocara—serology B. Onchocerca—skin snips C. Dracunculus—skin biopsy D. Angiostrongylus—CSF examination
A
A. Toxocara—serology
15
Q
The following organisms are linked with
specific, relevant information. The incorrect
combination is:
A. Strongyloides stercoralis—internal autoinfection
B. Echinococcus granulosus—hydatid examination
C. Toxoplasma—serology
D. Balantidium coli—common within the
United States
A
D. Balantidium coli—common within the
United States
16
Q
Examination of 24-hour unpreserved urine specimen is sometimes helpful in the recovery of: A. Trichomonas vaginalis trophozoites B. Schistosoma haematobium eggs C. Enterobius vermicularis eggs D. Strongyloides stercoralis larvae
A
B. Schistosoma haematobium eggs
17
Q
The examination of sputum may be necessary to diagnose infection with: A. Paragonimus westermani B. Trichinella spiralis C. Wuchereria bancrofti D. Fasciola hepatica
A
A. Paragonimus westermani
18
Q
Two helminth eggs that may resemble one
another are:
A. Diphyllobothrium latum and Paragonimus
westermani
B. Opisthorchis sinensis and Fasciolopsis buski
C. Taenia saginata and Hymenolepis nana
D. Ascaris lumbricoides and Trichostrongylus
A
A. Diphyllobothrium latum and Paragonimus
westermani
19
Q
Eating poorly cooked pork can lead to an
infection with:
A. Taenia solium and Trichinella spiralis
B. Taenia saginata and Hymenolepis nana
C. Trichuris trichiura and Hymenolepis diminuta
D. Diphyllobothrium latum and Ascaris lumbricoides
A
A. Taenia solium and Trichinella spiralis
20
Q
An operculated cestode egg that can be recovered from human feces is: A. Clonorchis sinensis B. Diphyllobothrium latum C. Paragonimus westermani D. Dipylidium caninum
A
B. Diphyllobothrium latum
21
Q
The adult tapeworm of Echinococcus granulosus is found in the intestine of: A. Dogs B. Sheep C. Humans D. Cattle
A
A. Dogs
22
Q
In infections with Taenia solium, humans can
serve as the:
A. Definitive host
B. Intermediate host
C. Either the definitive or the intermediate host
D. None of these options
A
C. Either the definitive or the intermediate host
23
Q
Humans acquire infections with Diphyllobothrium latum adult worms by: A. Ingestion of freshwater crabs B. Skin penetration of cercariae C. Ingestion of water chestnuts D. Ingestion of raw freshwater fish
A
D. Ingestion of raw freshwater fish
24
Q
Humans can serve as both the intermediate and definitive host in infections caused by: A. Enterobius vermicularis B. Hymenolepis nana C. Schistosoma japonicum D. Ascaris lumbricoides
A
B. Hymenolepis nana
25
Babesia has been implicated in disease from both
splenectomized and nonsplenectomized patients.
Morphologically, the parasites resemble:
A. Plasmodium falciparum rings
B. Leishmania donovani amastigotes
C. Trypanosoma cruzi trypomastigotes
D. Microsporidial spores
A. Plasmodium falciparum rings
26
Organisms (and infections) that under normal
conditions cannot be transmitted in the
laboratory are:
A. Cryptosporidium—cryptosporidiosis
B. Taenia solium—cysticercosis
C. Ascaris lumbricoides—ascariasis
D. Enterobius vermicularis—pinworm infections
C. Ascaris lumbricoides—ascariasis
27
Toxoplasma gondii is characterized by:
A. Possible congenital infection and ingestion of
oocysts
B. Cosmopolitan distribution and possible
difficulties with interpretation of serological
results
C. Neither A nor B
D. Both A and B
D. Both A and B
28
Oocysts of Cryptosporidium spp. can be detected
in stool specimens using:
A. Modified Ziehl–Neelsen acid-fast stain
B. Gram stain
C. Methenamine silver stain
D. Trichrome stain
A. Modified Ziehl–Neelsen acid-fast stain
29
```
Which microfilariae are usually not found
circulating in the peripheral blood?
A. Brugia malayi
B. Wuchereria bancrofti
C. Onchocerca volvulus
D. Loa loa
```
C. Onchocerca volvulus
30
Massive hemolysis, blackwater fever, and
central nervous system involvement are most
common with:
A. Plasmodium vivax
B. Plasmodium falciparum
C. Plasmodium ovale
D. Plasmodium malariae
B. Plasmodium falciparum
31
Organisms that should be considered in a nursery
school outbreak of diarrhea include:
A. Endolimax nana, Giardia lamblia, and
Entamoeba coli
B. Giardia lamblia, Dientamoeba fragilis, and
Cryptosporidium spp.
C. Cryptosporidium spp., Trichomonas vaginalis,
and Entamoeba coli
D. Pentatrichomonas hominis, Dientamoeba fragilis,
and Endolimax nana
B. Giardia lamblia, Dientamoeba fragilis, and
| Cryptosporidium spp.
32
```
The incorrect match between disease and
symptoms is:
A. Paragonimiasis—hemoptysis
B. Cryptosporidiosis—watery diarrhea
C. Toxoplasmosis in compromised host—central
nervous system symptoms
D. Enterobiasis—dysentery
```
D. Enterobiasis—dysentery
33
The formalin–ether (ethyl acetate) concentration
procedure for feces is used to demonstrate:
A. Motility of helminth larvae
B. Protozoan cysts and helminth eggs
C. Formation of amoebic pseudopods
D. Trophozoites
B. Protozoan cysts and helminth eggs
34
Cysts of Iodamoeba bütschlii typically have:
A. Chromatoidal bars with rounded ends
B. A heavily vacuolated cytoplasm
C. A large glycogen vacuole
D. Many ingested bacteria and yeast cells
C. A large glycogen vacuole
35
```
The miracidial hatching test helps to demonstrate
the viability of eggs of:
A. Taenia species
B. Schistosoma species
C. Hookworm species
D. Opisthorchis species
```
B. Schistosoma species
36
Organisms that should be considered in a
waterborne outbreak of diarrheal disease include:
A. Giardia lamblia and Cryptosporidium spp.
B. Endolimax nana and Entamoeba histolytica
C. Blastocystis hominis and Trichomonas vaginalis
D. Toxoplasma gondii and Schistosoma mansoni
A. Giardia lamblia and Cryptosporidium spp.
37
Fecal immunoassays have become more commonly
used to diagnose infections with:
A. Endolimax nana and Blastocystis hominis
B. Giardia lamblia and Cryptosporidium spp.
C. Ascaris lumbricoides and Trichuris trichiura
D. Strongyloides stercoralis and Trichomonas vaginalis
B. Giardia lamblia and Cryptosporidium spp
38
```
Primary infections with the microsporidia may
originate in:
A. The lung
B. The nervous system
C. The gastrointestinal tract
D. Mucocutaneous lesions
```
C. The gastrointestinal tract
39
Eye infections with Acanthamoeba spp. have most
commonly been traced to:
A. Use of soft contact lenses
B. Use of hard contact lenses
C. Use of contaminated lens care solutions
D. Failure to remove lenses while swimming
C. Use of contaminated lens care solutions
40
Select the most sensitive recovery method for
Acanthamoeba spp. from lens care solutions or
corneal biopsies.
A. The trichrome staining method
B. The use of monoclonal reagents for the detection
of antibody
C. The use of non-nutrient agar cultures seeded
with Escherichia coli
D. The Giemsa’s stain method
C. The use of non-nutrient agar cultures seeded
| with Escherichia coli
41
The microsporidia are protozoans (now classified
with the fungi) that have been implicated in
human disease primarily in:
A. Immunocompromised patients
B. Pediatric patients under the age of 5 years
C. Adult patients with congenital
immunodeficiencies
D. Patients who have been traveling in the tropics
A. Immunocompromised patients
42
When staining Cystoisospora belli oocysts with
modified acid-fast stains, the important difference
between these methods and the acid-fast stains
used for acid-fast bacilli (AFB) is:
A. The staining time is much longer with regular
AFB acid-fast stains
B. The decolorizer is weaker than acid alcohol used
for AFB decolorizing
C. A counterstain must be used for the modified
methods
D. The stain is more concentrated when staining
for AFB
B. The decolorizer is weaker than acid alcohol used
| for AFB decolorizing
43
```
The incorrect match between symptoms and
disease is:
A. Dysentery—amebiasis
B. Malabsorption syndrome—giardiasis
C. Cardiac involvement—chronic Chagas disease
D. Myalgias—trichuriasis
```
D. Myalgias—trichuriasis
44
The incorrect match between organism and
characteristic is:
A. Chilomastix mesnili—Shepherd’s crook and
lemon shape
B. Plasmodium malariae—“band troph”
C. Hymenolepis nana—striated shell
D. Wuchereria bancrofti—sheathed microfilariae
C. Hymenolepis nana—striated shell
45
The incorrect match between method and method
objective is:
A. Direct wet examination—detection of organism
motility
B. Knott’s concentration—the recovery of
operculated helminth eggs
C. Baermann’s concentration—the recovery of
Strongyloides
D. Permanent stained fecal smear—confirmation
of protozoa
B. Knott’s concentration—the recovery of
| operculated helminth eggs
46
The incorrect match between organism and
characteristic is:
A. Dientamoeba fragilis—tetrad karyosome in the
nucleus
B. Toxoplasma gondii—diagnostic serology
C. Echinococcus granulosus—daughter cysts
D. Schistosoma mansoni—egg with terminal spine
D. Schistosoma mansoni—egg with terminal spine
47
There are few procedures considered STAT in
parasitology. The most obvious situation would be:
A. Ova and parasite examination for giardiasis
B. Baermann’s concentration for strongyloidiasis
C. Blood films for malaria
D. Culture of amoebic keratitis
C. Blood films for malaria
48
An immunosuppressed man has several episodes
of pneumonia, intestinal pain, sepsis with
gram-negative rods, and a history of military
service in Southeast Asia 20 years earlier. The
most likely cause is infection with:
A. Trypanosoma cruzi
B. Strongyloides stercoralis
C. Naegleria fowleri
D. Paragonimus westermanI
B. Strongyloides stercoralis
49
In a pediatric patient, the recommended clinical
specimen for recovery of Enterobius vermicularis
is the:
A. Stool specimen
B. Sigmoidoscopy scrapings
C. Duodenal aspirates
D. Series of Scotch tape preparations
D. Series of Scotch tape preparations
50
```
Which parasite causes eosinophilic
meningoencephalitis, a form of larva
migrans causing fever, headache, stiff neck,
and increased cells in the spinal fluid?
A. Necator americanus
B. Angiostrongylus cantonensis
C. Ancylostoma braziliense
D. Strongyloides stercoralis
```
B. Angiostrongylus cantonensis
51
“Cultures of parasites are different from bacterial
cultures; no quality control is needed.” This
statement is:
A. True, if two tubes of media are set up for each
patient
B. True, if the media are checked every 24 hours
C. False, unless two different types of media are used
D. False, and organism and media controls need to
be set up
D. False, and organism and media controls need to
| be set up
52
Protozoan cysts were seen in a concentration
sediment and tentatively identified as Entamoeba
coli. However, the organisms were barely visible
on the permanent stained smear because:
A. The organisms were actually not present in the
concentrate sediment
B. There were too few cysts to allow identification
on the stained smear
C. E. coli cysts were present but poorly fixed
D. The concentrate and permanent stained smear
were not from the same patient
C. E. coli cysts were present but poorly fixed
53
When humans have hydatid disease, the causative
agent and host classification are:
A. Echinococcus granulosus—accidental
intermediate host
B. Echinococcus granulosus—definitive host
C. Taenia solium—accidental intermediate host
D. Taenia solium—definitive host
A. Echinococcus granulosus—accidental
| intermediate host
54
A 45-year-old hunter developed fever, myalgia, and
periorbital edema. He has a history of bear meat
consumption. The most likely causative agent is:
A. Toxoplasma gondii
B. Taenia solium
C. Hymenolepis nana
D. Trichinella spiralis
D. Trichinella spiralis
55
```
In a condition resulting from the accidental
ingestion of eggs, the human becomes the
intermediate rather than the definitive host. The
correct answer is:
A. Trichinosis
B. Cysticercosis
C. Ascariasis
D. Strongyloidiasis
```
B. Cysticercosis
56
A transplant patient on immunosuppressive
drugs developed increasing diarrhea. The most
likely combination of disease and diagnostic
procedure is:
A. Trichinosis and trichrome stain
B. Microsporidiosis and modified trichrome stain
C. Toxoplasmosis and Gram stain
D. Paragonimiasis and wet preparation
B. Microsporidiosis and modified trichrome stain
57
After returning from a 2-year stay in India, a
patient has eosinophilia, an enlarged left spermatic
cord, and bilateral inguinal lymphadenopathy.
The most likely clinical specimen and organism
match is:
A. Thin blood films—Leishmania
B. Urine—concentration for Trichomonas vaginalis
C. Thin blood films—Babesia
D. Thick blood films—microfilariae
D. Thick blood films—microfilariae
58
Patients with severe diarrhea should use
“enteric precautions” to prevent nosocomial
infections with:
A. Giardia lamblia
B. Ascaris lumbricoides
C. Cryptosporidium spp.
D. Cystoisospora belli
C. Cryptosporidium spp.
59
A 60-year-old Brazilian patient with cardiac
irregularities and congestive heart failure suddenly
dies. Examination of the myocardium revealed
numerous amastigotes, an indication that the
cause of death was most likely:
A. Leishmaniasis with Leishmania donovani
B. Leishmaniasis with Leishmania braziliense
C. Trypanosomiasis with Trypanosoma gambiense
D. Trypanosomiasis with Trypanosoma cruzi
D. Trypanosomiasis with Trypanosoma cruzi
60
When malaria smears are requested, what patient
information should be obtained?
A. Diet, age, sex
B. Age, antimalarial medication, sex
C. Travel history, antimalarial medication, date of
return to United States
D. Fever patterns, travel history, diet
C. Travel history, antimalarial medication, date of
| return to United States
61
In an outbreak of diarrheal disease traced to a
municipal water supply, the most likely causative
agent is:
A. Cryptosporidium spp.
B. Cystoisospora belli
C. Entamoeba histolytica
D. Dientamoeba fragilis
A. Cryptosporidium spp.
62
Within the United States, sporadic mini-outbreaks
of diarrheal disease have been associated with the
ingestion of strawberries, raspberries, fresh basil,
mesclun (baby lettuce leaves), and snow peas. The
most likely causative agent is:
A. Dientamoeba fragilis
B. Cyclospora cayetanensis
C. Schistosoma mansoni
D. Cystoisospora belli
B. Cyclospora cayetanensis
63
Which of the following statements is true
regarding onchocerciasis?
A. The adult worm is present in the blood
B. The microfilariae are in the blood during the late
evening hours
C. The diagnostic test of choice is the skin snip
D. The parasite resides in the deep lymphatics
C. The diagnostic test of choice is the skin snip
64
The most prevalent helminth to infect humans is:
A. Enterobius vermicularis, the pinworm
B. Ascaris lumbricoides, the large intestinal
roundworm
C. Taenia saginata, the beef tapeworm
D. Schistosoma mansoni, one of the blood flukes
A. Enterobius vermicularis, the pinworm
65
A helminth egg is described as having terminal
polar plugs. The most likely helminth is:
A. Hookworm
B. Trichuris trichiura
C. Fasciola hepatica
D. Diphyllobothrium latum
B. Trichuris trichiura
66
```
Ingestion of which of the following eggs will result
in infection?
A. Strongyloides stercoralis
B. Schistosoma japonicum
C. Toxocara canis
D. Opisthorchis sinensis
```
C. Toxocara canis
67
Plasmodium vivax and Plasmodium ovale are
similar because they:
A. Exhibit Schüffner’s dots and have a true relapse
in the life cycle
B. Have no malarial pigment and multiple rings
C. Commonly have appliqué forms in the red cells
D. Have true stippling, do not have a relapse stage,
and infect old red cells
A. Exhibit Schüffner’s dots and have a true relapse
| in the life cycle
68
The term internal autoinfection can be associated
with the following parasites:
A. Cryptosporidium spp. and Giardia lamblia
B. Cystoisospora belli and Strongyloides stercoralis
C. Cryptosporidium spp. and Strongyloides stercoralis
D. Giardia lamblia and Cystoisospora belli
C. Cryptosporidium spp. and Strongyloides stercoralis
69
Microsporidia have been identified as causing
severe diarrhea, disseminated disease in other body
sites, and ocular infections. Routes of infection
have been identified as:
A. Ingestion
B. Inhalation
C. Direct contamination from the environment
D. Ingestion, inhalation, and direct contamination
D. Ingestion, inhalation, and direct contamination
70
An immunocompromised patient continues
to have diarrhea after repeated ova and
parasites (O&P) examinations (sedimentation
concentration, trichrome permanent stained
smear) were reported as negative; organisms
that might be responsible for the diarrhea
include:
A. Cryptosporidium spp., Giardia lamblia,
and Cystoisospora belli
B. Giardia lamblia, microsporidia, and
Endolimax nana
C. Taenia solium and Endolimax nana
D. Cryptosporidium spp. and microsporidia
D. Cryptosporidium spp. and microsporidia
71
Confirmation of an infection with microsporidia
can be achieved by seeing:
A. The oocyst wall
B. Sporozoites within the spore
C. Evidence of the polar tubule
D. Organisms stained with modified acid-fast stains
C. Evidence of the polar tubule
72
```
Early ring stages of the fifth human malaria,
Plasmodium knowlesi, resemble those of:
A. Plasmodium malariae
B. Plasmodium ovale
C. Plasmodium falciparum
D. Plasmodium vivax
```
C. Plasmodium falciparum
73
Parasite stages that are immediately infective for
humans on passage from the gastrointestinal tract
include:
A. Schistosoma spp. eggs
B. Toxoplasma gondii bradyzoites
C. Giardia lamblia trophozoites
D. Cryptosporidium spp. oocysts
D. Cryptosporidium spp. oocysts
74
Older developing stages (trophs, schizonts) of the
fifth human malaria, Plasmodium knowlesi,
resemble those of:
A. Plasmodium malariae
B. Plasmodium ovale
C. Plasmodium falciparum
D. Plasmodium vivax
A. Plasmodium malariae
75
```
Autofluorescence requires no stain and is
recommended for the identification of:
A. Entamoeba histolytica cysts
B. Toxoplasma gondii tachyzoites
C. Dientamoeba fragilis trophozoites
D. Cyclospora cayetanensis oocysts
```
D. Cyclospora cayetanensis oocysts
76
Key characteristics of infection with Plasmodium
knowlesi include:
A. Rapid erythrocytic cycle (24 hr), will infect all
ages of RBCs, and can cause serious disease
B. Erythrocytic cycle limited to young RBCs and
causes a relatively benign disease
C. The possibility of a true relapse from the liver,
infection in older RBCs, and causes serious
disease
D. Extended life cycle (72 hr), will infect all ages
of RBCs, and disease is similar to that caused
by P. ovale
A. Rapid erythrocytic cycle (24 hr), will infect all
| ages of RBCs, and can cause serious disease
77
Microsporidial infections can be confirmed using:
A. Light microscopy and modified trichrome stains
B. Phase contrast microscopy and routine trichrome
stains
C. Electron microscopy and modified acid-fast
stains
D. Fluorescence microscopy and hematoxylin stains
A. Light microscopy and modified trichrome stains
78
Although the pathogenicity of Blastocystis
hominis remains controversial, newer information
suggests that:
A. Most organisms are misdiagnosed as artifacts
B. Numerous strains/species are included in the
name, some of which are pathogenic and some
are nonpathogenic
C. The immune status of the host is solely
responsible for symptomatic infections
D. The number of organisms present determines
pathogenicity
B. Numerous strains/species are included in the
name, some of which are pathogenic and some
are nonpathogenic
79
Potential problems using EDTA anticoagulant and
holding the blood too long prior to preparation of
thick and thin blood films include:
A. Changes in parasite morphology, loss of organisms
within several hours, and poor staining
B. Loss of Schüffner’s dots, poor adherence of the
blood to the glass slide, and parasites beginning
the vector cycle within the tube of blood
C. Neither A nor B
D. All of these options
D. All of these options
80
Which of the following is a key characteristic of
the thick blood film?
A. The ability to see the parasite within the RBCs
B. The ability to identify the parasites to the
species level
C. The examination of less blood than the thin
blood film
D. The necessity to lake the RBCs during or prior
to staining
D. The necessity to lake the RBCs during or prior
| to staining
