CLS review: Parasitology

In a patient w/ 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. PMNs c. epithelial cells d. eosinophils

b. PMNs

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

Examination of 24-hr unpreserved urine specimen is sometimes helpful in the recovery of: a. Trichomonas vaginalis trophs b. Schistosoma haematobium eggs c. Enterobius vermicularis eggs d. Strongyloides stercoralis larvae

b. Schistosoma haematobium eggs

Balantidium coli

This ciliate is considered the largest intestinal protozoan to parasitize humans. The large-kidney shaped macronucleus and cytostome aid in the identification of this trophozoite, which is ___ in trichrome stain.

Fasciola hepatica

This trematode egg recovered from feces is difficult to distinguish from "Fasciolopsis buski". The parasite is referred to as the SHEEP LIVER FLUKE. Which ovum is present?

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 caninum

b. Trichuris trichiura

Cryptosporidium spp.

oocysts 4-8 μm, colorless, transparent, difficult to see on fecal slides. Acid-fast staining is used

Hookworm

Diagnosis of this roundworm depends on demonstration of the eggs or larvae in stool specimens. Identify the roundworm egg shown

Plasmodium falciparum

Name the Plasmodium species based on the following information: No persistent liver stage or relapse; blood smear shows multiple ring forms and crescent-shaped gametes; irregular febrile pattern; associated with cerebral malaria

Schistosoma mansoni

The Schistosoma species with a prominent lateral spine is

Clonorchis sinensis

The adult trematode lives in the liver and is found in China, Japan, Korea, and Vietnam. What ovum is present?

Eating poorly cooked pork can lead to an infection with: a. Taenia solium and Trichinella spiralis b. Taenia saginata and Hymenolepsis nana c. Trichuris trichiura and Hymenolepsis diminuta d. Diphyllobothrium latum and Ascaris lumbricoides

a. Taenia solium and Trichinella spiralis

Visceral larva migrans is associated w/ which of the following organisms? a. Toxocara - serology b. Onchocerca - skin snips c. Dracunculus - skin biopsy d. Angiostrongylus - CSF exam

a. Toxocara - serology

Oocysts of Cryptosporidium spp can be detected in stool specimen using: a. modified Ziehl-Neelsen acid-fast stain b. Gram's stain c. Methenamine silver stain d. Trichrome stain

a. modified Ziehl-Neelsen acid-fast stain

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. short buccal capsule and large genital primordium

Select the most sensitive recovery method for Acanthamoeba spp from the lens care solutions or corneal biopsies: a. trichrome stain b. monoclonal reagents for the detection of Ab c. non-nutrient agar cultures seeded w/ E. coli d. Giemsa stain

c. non-nutrient agar cultures seeded w/ E. coli

Diphyllobothrium latum

This operculated "fish tapeworm" (cesatode) egg can be recovered from fecal specimens if pickled or raw freshwater fish are ingested. Which ovum is present?

Babesia microti

This organism mimics "Plasmodium falciparum" because many can infect a single RBC. It usually infects domestic and wild animals, but can cause human infection. The tetrad or "Matese cross" forms a characteristics. What parasites are present?

Entamoeba histolytica

This trophozoite represents the major amoebic pathogen for humans. The characteristic BULL's EYE nucleus, consisting a central karyosome and even, fine peripheral chromatin, helps identify this protozoan as:

Babesia is an organism that 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. Pneumocystis carinii cysts

a. Plasmodium falciparum rings

The incorrect match between the organism and one method of acquiring the infection is: a. Trypanosoma brucei rhodiense - 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. Trypanosoma brucei rhodiense - bite of sand fleas

An Entamoeba histolytica trophozoite has the following characteristics: a. central karysome 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 karysome, ingested WBCs, and granular pseudopods

a. central karysome in the nucleus, ingested RBCs, and clear pseudopodia

The microsporidia are protozoans that have been implicated in human disease primarily in: a. immunocompromised patients b. pediatric patients under the age of 5 c. adult patients w/ congenital immunodeficiencies d. patients who have been traveling to the tropics

a. immunocompromised patients

Within the U.S., sporadic mini-outbreaks of diarrheal disease have been associated w/ the ingestion of strawberries, raspberries, fresh basil, and mesclun (baby lettuce leaves). The most likely causative agent is: a. Dientamoeba fragilis b. Cyclospora cayetanensis c. Schistosoma mansoni d. Isospora belli

b. Cyclospora cayetanensis

An operculated cestode egg that can be recovered from human feces is: a. Clonorchis sinensis b. Diphyllobothrium latum c. Paragonimus westermani d. Dipylidium caninum

b. Diphyllobothrium latum

Charcot-Leyden crystals in stool may be associated w/ an immune response and are thought to be the breakdown products of: a. Neutrophils b. Eosinophils c. Monocytes d. Lymphocytes

b. Eosinophils

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 parvum c. Cryptosporidium parvum, Trichomonas vaginalis, and Entamoeba coli d. Trichomonas hominis, Dientamoeba fragilis, and Endolimax nana

b. Giardia lamblia, Dientamoeba fragilis, and Cryptosporidium parvum

Humans can serve as both the intermediate and definitive host in infections caused by: a. Enterobius vermicularis b. Hymenolepsis nana c. Schistosoma japonicum d. Ascaris lumbricoides

b. Hymenolepsis nana

The incorrect match between method and method objective is: a. direct wet examination and detection of organism motility b. Knott's concentration and the recovery of operculated helminth eggs c. Baermann's concentration and the recovery of Strongyloides d. permanent stained fecal smear and confirmation of protozoa

b. Knott's concentration and the recovery of operculated helminth eggs

A transplant patient on immunosuppressive drugs developed increasing shortness of breath and cyanosis. The most likely combination of disease and diagnostic procedure is: a. Strongyloidiasis and trichrome stain b. Pneumocystosis and silver stain c. Toxoplasmosis and Gram stain d. Paragonimiasis and wet prep

b. Pneumocystosis and silver stain

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

An immunosuppressed man has several episodes of pneumonia, intestinal pain, sepsis w/ gram-negative rods, and a history of military service in Southeast Asia 20 yrs earlier. The most likely cause is infection with: a. Trypanosoma cruzi b. Strongyloides stercoralis c. Naegleria fowleri d. Paragonimus westermani

b. Strongyloides stercoralis

Which of the following is the best technique to identify Dientamoeba fragilis in stool? a. Formalin concentration b. Trichrome-stained smear c. modified acid-fast-stained smear d. Giemsa's stain

b. Trichrome-stained smear

When staining Isospora belli oocysts w/ modified acid-fast stains, the important difference between these methods and the acid-fast stains used for AFB is: a. staining time is much longer w/ regular AFB acid-fast stains b. decolorizer is weaker than acid alcohol used for AFB decolorizing c. counterstain must be used for modified methods d. stain is more concentrated when staining for AFB

b. decolorizer is weaker than acid alcohol used for AFB decolorizing

BAL specimens have become much more widely used in: a. any suspect patient w/ both toxoplasmosis and cryptosporidiosis b. pediatric patients w/ pulmonary paragonimiasis c. AIDS patients w/ suspected Pneumocystis pneumonia d. Immunocompromised patients w/ disseminated strongyloides

c. AIDS patients w/ suspected Pneumocystis pneumonia

Organisms (and infections) that under normal conditions cannot be transmitted in the lab are: a. Cryptosporidium - cryptosporidiosis b. Taenia solium - cysticercosis c. Ascaris lumbricoides - ascariasis d. Enterobius vermicularis - pinworm infections

c. Ascaris lumbricoides - ascariasis

Patients w/ severe diarrhea should use enteric precautions to prevent nosocomial infections with: a. Giardia lamblia b. Ascaris lumbricoides c. Cryptosporidium parvum d. Isospora belli

c. Cryptosporidium parvum

The term internal autoinfection can be associated with the following parasites: a. Cryptosporidium parvum and Giardia lamblia b. Isospora belli and Strongyloides stercoralis c. Cryptosporidium parvum and Strongyloides stercoralis d. Giardia lamblia and Isospora belli

c. Cryptosporidium parvum and Strongyloides stercoralis

Protozoan cysts were seen in a concentrate sediment and tentatively identified as Entamoeba coli. However, the organisms were barely visible on the permanent stained smear because: a. 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

The incorrect match between organism and the appropriate diagnostic procedure is: a. Ochocerca volvulus - examination of skin snips b. Cryptosporidium - modified acid fast stain c. Echinococcus granulosus - routine ova and parasite exam d. Schistosoma haematobium - examination of urine sediment

c. Echinococcus granulosus - routine ova and parasite exam

A Gram stain from a gum lesion showed what appeared to be amoebae. A trichrome smear showed amoebae w/ a single nucleus and partially digested PMNs. The correct ID is: a. Trichomonas tenax b. Entamoeba histolytica/E. dispar c. Entamoeba gingivalis d. Entamoeba polecki

c. Entamoeba gingivalis

One of the following protozoan organisms has been implicated in waterborne and foodborne outbreaks within the U.S. The suspect organism is: a. Trichomonas hominis b. Dientamoeba fragilis c. Giardia lamblia d. Balantidium coli

c. Giardia lamblia

The incorrect match between organisms and characteristic is: a. Chilomastix mesnili and Shepherd's crook and lemon shape b. Plasmodium malariae and band troph c. Hymenolepsis nana and striated shell d. Wuchereria bancrofti and sheathed microfilariae

c. Hymenolepsis nana and striated shell

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

When malaria smears are requested, what patient info should be obtained? a. diet, age, sex b. age, antimalarial medication, date of return to U.S. c. Travel history, antimalarial medication, date of return to U.S. d. fever patterns, travel history, diet

c. Travel history, antimalarial medication, date of return to U.S.

Parasitic organisms that are most often transmitted sexually include: a. Entamoeba gingivalis b. Dientamoeba fragilis c. Trichomonas vaginalis d. Diphyllobothrium latum

c. Trichomonas vaginalis

Cysts of Iodamoeba butschlii typically have: a. Chromatoidal bars w/ rounded ends b. a heavily vacuolated cytoplasm c. a large glycogen vacuole d. many ingested bacteria and yeast cells

c. a large glycogen vacuole

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 hrs 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

A 12-yr-old girl is brought to the ER w/ meningitis and a history of swimming in a warm-water spring. Motile amoebae that measure 10 um in size are seen in the CSF and are most likely: a. Iodamoeba butschlii trophs b. Endolimax nana trophs c. Dientamoeba fragilis trophs d. Naegleria fowleri trophs

d. Naegleria fowleri trophs

The incorrect match between organism and characteristic is: a. Dientamoeba fragilis and tetrad karysome in the nucleus b. Toxoplasma gondii and diagnostic serology c. Echinococcus granulosus and daughter cysts d. Schistosoma mansoni and egg w/ terminal spine

d. Schistosoma mansoni and egg w/ terminal spine

A 45-yr-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. Hymenolepsis nana d. Trichinella spiralis

d. Trichinella spiralis

Paragonimus westermani

Operculated eggs in sputum or feces. It's also called a lung fluke- adults live in the lung parenchyma. get it from eating undercooked crab meat.

Giardia lamblia

The cysts of this flagellate survive in food and water and can be missed in stool samples if a permanent stain smear is not included. Which flagellate is present? (It is also the most often diagnosed protozoan flagellates)

Plasomodium vivax

The most frequent and widely distributed cause of recurring malaria. This peripheral blood film depicts which organism?

Plasmodium vivax

The presence of ring form trophozoites and Schuffner's dots may indicate:

Trichuris trichiura

"whipworm" roundworm (nematodes). The adult worms are rarely seen, but the eggs of this intestinal nematode are characteristic and readily diagnosed in fecal specimen. Which roundworm is this?

There are few procedures considered stat in parasitology. The most obvious situations would be: a. ova and parasite exam for giardiasis b. Baermann's concentration for strongyloidiasis c. blood films for malaria d. culture of amoebic keratitis

c. blood films for malaria

Which of the following statements is true regarding onchocerciasis? a. adult worm is present in blood b. microfilariae are in the blood during the late evening hrs c. diagnostic test of choice is the skin snip d. parasite resides in the deep lymphatics

c. diagnostic test of choice is the skin snip

In infections w/ Taenia solium, humans can serve as the: a. definitive host b. intermediate host c. either the definitive or the intermediate host d. none of the above

c. either the definitive or the intermediate host

Primary infections w/ microsporidia may originate in: a. the lung b. the nervous system c. the GI tract d. mucocutaneous lesions

c. the GI tract

Eye infections w/ 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

The following organisms are linked w/ specific, relevant information. The incorrect combination is: a. Strongyloides stercoralis - internal autoinfection b. Echinococcus granulosus - hydatid examination c. Pneumocystis carinii - more than 50% of population Ab-pos by age 4 d. Balantidium coli - common w/in the U.S.

d. Balantidium coli - common w/in the U.S.

An immunocompromised patient continues to have diarrhea after repeated ova and parasites exam (sedimentation concentration, trichrome permanent stained smear) were reported as negative; organisms that might be responsible for the diarrhea include: a. Cryptosporidium parvum, Giardia lamblia, and Isospora belli b. Giardia lamblia, microsporidia, and Endolimax nana c. Taenia solium and Endolimax nana d. Cryptosporidium parvum and microsporidia

d. Cryptosporidium parvum and microsporidia

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 - dysentary

d. Enterobiasis - dysentary

A 60-yr old Brazilian patient w/ cardiac irregularities and CHF suddenly dies. Examination of the myocardium revealed numerous amastigotes, an indication that the cause of death was most likely: a. Leishmaniasis w/ Leishmania donovani b. Leishmaniasis w/ Leismania braziliense c. Trypanosomiasis w/ Trypanosoma gambiense d. Trypanosomiasis w/ Trypanosoma cruzi

d. Trypanosomiasis w/ Trypanosoma cruzi

Toxoplasma gondii is characterized by: a. possible congenital infection and ingestion of oocysts b. cosmopolitan distribution and possible difficulties w/ interpretation of serological results c. none of the above d. both A and B

d. both A and B

Which specimen is the LEAST likely to provide recovery of Trichomonas vaginalis? a. urine b. urethral discharge c. vaginal discharge d. feces

d. feces

Humans can acquire infections w/ 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

d. ingestion of raw freshwater fish

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

The incorrect match between symptoms & disease is: a. dysentery and amebiasis b. malabsorption syndrome and giardiasis c. cardiac involvement and chronic Chagas' disease d. myalgias and trichuriasis

d. myalgias and trichuriasis

In a non-AIDS patient, the recommended clinical specimen for recovery of Pneumocystis carinii is the: a. tracheobronchial aspirate b. BAL c. bronchial brushings d. open-lung biopsy

d. open-lung biopsy

Hookworm eggs and Ascaris lumbricoides

Mixed infections with these two parasites are often seen in fecal specimens. Which two ova are present?

Plasmodium vivax and Plasmodium ovale are similar because they: a. Exhibit Schuffner's dots and have a true relapse in the life cycle b. Have no malarial pigment and multiple rings c. Commonly have applique forms in RBCs d. have true stippling, do not have a relapse stage, and infect old RBCs

a. Exhibit Schuffner's dots and have a true relapse in the life cycle

The examination of sputum may be necessary to diagnose infection w/: a. Paragonimus westermani b. Trichinella spiralis c. Wuchereria bancrofti d. Fasciola hepatica

a. Paragonimus westermani

The adult tapeworm of Echinococcus granulosus is found in the intestine of: a. dogs b. sheep c. humans d. cattle

a. dogs

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

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

Upon examination of stool material for Isospora belli, one would expect to see: a. Cysts containing sporozoites b. Precysts containing chromatoidal bars c. Oocysts that are acid-fast d. Sporozoites that are hematoxylin-positive

c. Oocysts that are acid-fast

After returning from a 2-yr stay in India, a patient has eosinophilia, an enlarged left spermatic cord, and bilateral inguinal lymphadenopathy. Most likely clinical specimen and organism match is: a. thin blood films and Leishmania b. urine and concentration for Trichomonas vaginalis c. thin blood films and Babesia d. thick blood films and microfilariae

d. thick blood films and microfilariae

Schistosoma japonicum

The eggs of this blood flukes are mainly in Southeast Asia and are passed in the stool. Which ovum is present in this field?

Toxoplasma gondii

The trophozoite form of this parasite is ingested by humans through infected meat. It can also be a parasite from the house cat. What organism is present?

Trypanosoma cruzi

The trypomastigote stage found in peripheral blood is diagnostic for the identification of Chagas disease, a disorder caused by which organism?

Enterobius vermicularis

The eggs seen here of this nematode usually are detected by the "cellophane tape" or "Scotch tape" test because the eggs are deposited around the perianal region and are not found in stool specimen. The ova of which roundworm is present?

Ascaris lumbricoides

The fertilized egg of this large intestinal nematode sometimes with thick, mammilated coating. The eggs of which roundworm are present?

Entamoeba coli

The protozoan displayed is a cyst of ____

Taenia solium

These eggs were recovered from a stool specimen from a patient who repeatedly ate undercooked pork. Which tapeworm eggs are present?

Schistosoma haematobium

This characteristic (trematode) egg was recovered from centrifuged urine. The patient was a recent traveler to the Nile River Valley. Adult flukes (flatworm) reside in the veins of the bladder and adjacent organs. :Blood Fluke. What ovum is present?

In an outbreak of diarrheal disease traced to a municipal water supply, the most likely causative agents are: a. Cryptosporidium parvum and Giardia lamblia b. Giardia lamblia and Isospora belli c. Isospora belli and Entamoeba histolytica d. Entamoeba histolytica and Dientamoeba fragilis

a. Cryptosporidium parvum and Giardia lamblia

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 Hymenolepsis nana d. Ascaris lumbricoides and Trichostrongylus

a. Diphyllobothrium latum and Paragonimus westermani

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

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

Organisms that should be considered in a waterborne outbreak of diarrheal disease include: a. Giardia lamblia and Cryptosporidium parvum b. Endolimax nana and Entamoeba histolytica c. Blastocystis hominis and Trichomonas vaginalis d. Toxoplasma gondii and Schistosoma mansoni

a. Giardia lamblia and Cryptosporidium parvum

Eosinophilic meningoencephalitis is a form of larva migrans, causing fever, headache, stiff neck, and increased cells in the spinal fluid. It is generally a mild and self-limited infection and is caused by: a. Necator americanus b. Angiostrongylus cantonensis c. Ancylostoma braziliense d. Strongyloides stercoralis

b. Angiostrongylus cantonensis

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